Designing context-based teaching materials by transforming authentic scientific modelling practices in chemistry

ABSTRACT

One of the challenges of context-based science education is to construct high quality teaching materials. This paper presents results from a study investigating the heuristic value of an activity-based instructional framework for transformation of authentic scientific practices for use in the science classroom, in line with cultural historic activity theory (CHAT). The activity-based instructional framework was used to transform the authentic practice of Modelling Human Exposure and Uptake of Chemicals in Consumer Products into a curriculum unit. The transformation was conducted by experienced chemistry teachers well informed about CHAT. The heuristic value was judged on criteria completeness, instructiveness and appreciation. Collected data are designed curriculum materials and a focus group interview. Analysis of the designed curriculum materials indicated that the framework was highly complete and instructive, except for evoking reflection in students. Most important, the framework proved successful in operationalising CHAT into concrete guidelines for educational design. Additionally, the results show that the instructional framework is highly appreciated by the users. Further development of such instructional frameworks is important, since it fosters the construction of high quality context-based curriculum materials.

KEYWORDS:

• Context-based learning
• learning activities
• cultural historical activity theory (CHAT)

Introduction

Increasingly, contexts are being introduced in science curricula in many countries across the world (George & Lubben, 2002; Pilot & Bulte, 2006; Smith, 2011). The central feature of context-based learning environments is the use of realistic contexts as starting point and anchor for learning science, thereby giving significance and meaning to the science-content (Aikenhead, 1994; Bennett, Lubben, & Hogarth, 2007), as well as offering students to become engaged in scientific thinking and practice (Schwartz, Lederman, & Crawford, 2004). However, the success of context-based education is heavily dependent on the quality of the curriculum materials and implementation in classroom. In the special issue on context-based education, Pilot and Bulte (2006) described a number of hindering and fostering factors which are summarised in three categories:

• The nature of the design and developmental process, including the cyclic nature of the design and developmental process, the influence of the attitude of teachers as a key factor for success or failure of the innovation and the use of the collected data in the cyclic developmental process;

• Key characteristics of the course-design framework, including the quality of the frameworks for context-based chemistry education and the robustness of the design in the formal curriculum;

• Conditional circumstances during the development, including the assessment of learning results, requirements from stakeholders in further education and the quality of the team of developers within a systemic organisation.

This paper will zoom in on the second category, i.e. the key characteristics of a course-design framework from the perspective of experienced chemistry teachers as designers of context-based curriculum materials. Vos, Taconis, Jochems, and Pilot (2010) studied how beginning and proficient teachers when confronted with context-based materials, failed or succeeded in actually creating context-based learning environments. They argue that for experienced science teachers besides concrete and direct instruction in using the materials, teachers are also required to have knowledge of the rationale behind the materials, and should have the skills necessary to actually create a context-based learning environment while using the materials. However, in many cases teachers do not have access to the resources and information that they need to make pedagogical decisions that reflect the goals and rationale underlying a reform of a curriculum (Loucks-Horsley, Love, Hewson, Stiles, & Mundry, 2003). A course-design framework is intended to bridge the rationale and pedagogical orientation of curriculum reform and the learning environment. Course-design frameworks, also denoted as instructional frameworks, are intended to provide guidelines of the construction of teaching materials, thereby also providing a base for evaluating classroom enactments of designed education.

Within the context-based innovation several instructional frameworks have been described and utilised. The Chemistry in Context innovation (Schwartz, 2006) presents a framework in terms of the spider-web metaphor; the information and activities that introduce each chapter, student decision-making activities, questions, and tasks; laboratory work; assessments, etc. This pattern of elements constitutes the backbone of teaching and learning. In the Salters Advanced Chemistry project (Bennett & Lubben, 2006), the need-to-know principle has been elaborated in the characteristic three course components: Storylines, Chemical Ideas and the Activity Folder. Each unit is driven by the Storyline. From this, students are referred to the Activity Folder and Chemical Ideas, which forms the backbone of the students’ mental maps of chemical knowledge through a ‘drip-feed’ approach (spiral curriculum). The context-base chemistry innovation in Germany, denoted ‘Chemie im Kontext’, explicitly prescribes a four-phase framework that is used as a guideline for the development of exemplar units (Parchmann et al., 2006). The four phases, i.e. a contact phase, a curiosity phase, an elaboration phase and a phase of deepening and connection, contain essential aspects derived from instructional theories and theories about motivation. In the Industrial Chemistry (Hofstein & Kesner, 2006) movement a pattern is used that is characteristic for all elaborations of the programme: varied-type learning methods and classroom environments (lab, excursion, computer, classroom), and diversity of resources, among others a collection of enrichment materials. In short, all above context-based innovations consider instructional frameworks important instruments in the curriculum reform process. Nevertheless, there is no in-depth empirical information available about the interaction between teachers and instructional frameworks in the construction of curriculum materials, or about the extent to which such instructional frameworks guide and facilitate the design activities of teachers (Edelson, 2001).

In previous research studies, the authors of this paper developed and used an activity-based instructional framework for the design of curriculum units (Prins, Bulte, & Pilot, 2016), founded on the cultural historic activity theory (CHAT) (Leont'ev, 1978; Vygotsky, 1978). This framework aims to support educational designers in transforming authentic science practices into contexts for learning. We envision the activity-based instructional framework as a cognitive tool to support the educational designer to understand, remember, and address important components of CHAT while developing teaching materials and planning learning activities for students to conduct. The goal of this paper is to investigate the heuristic value of the activity-based instructional framework on criteria completeness, instructiveness and acceptance. Six chemistry teachers, well informed about CHAT, transformed the authentic practice of ‘modelling human exposure and uptake of chemicals in consumer products’ into a curriculum unit for use in classroom. Their pedagogical decisions were collected during a participatory design (PD) process (Foster, Dimmock, & Bersani, 2008; Mankin, Cohen, & Sikson, 1997). This study contributes to further development of high quality instructional frameworks in line with CHAT, which are needed for further systematic development and evaluation of context-based curricula.

Theoretical background

This section first focusses on context-based approaches building on the cultural historic activity theory (CHAT). Next, it describes the activity-based instructional framework as a design tool. The section ends with a reflection on the heuristic value of instructional frameworks for educational design activities.

Contexts building on CHAT

We transform authentic practices embedded in society into contexts for use in pre-university chemistry education (Bulte, Westbroek, De Jong, & Pilot, 2006), in order to achieve coherency between knowledge, skills, activities and attitudes. An authentic practice is characterised by employees working on a defined issue according to standardised procedures using relevant knowledge and tools, and connected by shared purposes, motives and attitudes (Prins, Bulte, Van Driel, & Pilot, 2008). During the transformation process, it is essential to maintain the natural coherency residing in an authentic practice within the constraints of the science classroom. Using an authentic practice as source of inspiration provides an educational designer a set of criteria and arguments to implement essential aspects of an authentic practice in a context for use in science education.

This view on, and use of, authentic science practices in education relates to cultural historic activity theory (CHAT) (Engestrom, 1987; Leont'ev, 1978; Van Aalsvoort, 2004) and complies to great extent to contexts defined as the ‘social circumstances’ as described by Gilbert (2006). CHAT builds on principles of sociocultural theories on learning (Van Oers, 1998) and adopts a dialectic materialist view of activity and consciousness as dynamically interrelated (Leont'ev, 1972). When we act, we gain knowledge, which affects our activities, which changes our knowledge and so on. This reciprocal process is critical to the conception of learning in CHAT. Central elements in CHAT are a goal-oriented activity, an object of the activity (mental or physical product) and a subject engaged in the activity (individual or group of actors). The activity is mediated by artefacts, such as tools (physical, such as hammers, or mental, such as heuristics, theories or concepts), and by rules and division of labour in a community. In line with other sociocultural theories on learning, CHAT emphasises learning as a result of goal-directed activity. In addition, the use of artefacts which are not associated with goal-directed activity have no meaning. Using CHAT as a basis for learning in formal science education involves the transformation of authentic scientific practices into classroom activity systems. This means that the students are assigned learning tasks that resemble characteristic activities in an authentic scientific practice. When carrying out these tasks, the learner becomes acquainted with the artefacts belonging to that authentic scientific practice. This includes the language used, via genres like talks, reports, articles, or designs. Other artefacts are the scientific procedures to be followed and, for example, laboratory equipment. Equally important are the values and attitudes that are inherent in an authentic scientific practice, as well as the quality standards. In the Methods section, an explicit example of an authentic chemical modelling practice is given, highlighting among others the characteristic modelling procedure, the content knowledge involved (i.e. the concepts and/or theories) and the societal embeddedness of the practice.

The National Academy of Science has stressed the importance of ‘developing students’ knowledge of how science and engineering achieve their ends while also strengthening their competency with related practices’ (National Academy of Sciences, 2012, p. 41). However, while the use of authentic practices in science education has gained attention (Abraham, 1998; Kelly, 2008; Kelly, Carlsen, & Cunningham, 1993) the strategy is not routinely applied in schools. This might be due to the fact that it is difficult to render complex, multifaceted practices into practically feasible learning environments within the constraints of the classroom. Currently, we lack concrete examples of curriculum units based on authentic practices and/or specific design knowledge for the transformation of authentic science practices into contexts for learning. As for the latter, however, when designing new curriculum units, this is precisely where knowledge about authentic practices, students’ learning demands and the conditions at schools is needed.

Activity-based instructional framework

During educational design processes, there is a variety of decisions to be made regarding the specific content, the type of classroom activity, the respective roles of teacher and students, the teaching resources, the various possibilities of class organisation etc. To address these questions, the ‘design-based research collective’ suggests ‘sharable theories’ that help to communicate relevant implications to educational designers (The design-based research collective, 2003). These ‘sharable theories’ should consist of guidelines, rules, heuristics and theoretical aspects at different levels of abstraction, thus linking general philosophical orientations with the actual teaching and learning in the classroom. In addition, such ‘sharable theories’ should offer opportunities to be investigated empirically in order to improve, refine or refute the ‘sharable theory’. An instructional framework can be regarded as such a ‘sharable theory’. An instructional framework relates specific instructional events to learning processes and learning outcomes, identifies instructional conditions that optimise learning outcomes, and provides a rational description of causal relationships between procedures used to teach and their behavioural consequences in enhanced human performance (Reigeluth, 1999).

The activity-based instructional framework, depicted in Table 1, consist of three components. First of all, the learning trajectory is divided into five distinct phases, with explicit modes of learning, such as orienting, planning or reflecting, which we developed in earlier studies (Bulte et al., 2006; Prins et al., 2016). The five learning phases are listed in the left-hand column. The pedagogical functions (PFs), listed in the second column from the left in Table 1, describe the desired pedagogical outcomes of the learning activities in each learning phase. The pedagogical functions link the design guidelines (third column from the left) with a spectrum of learning objectives, such as motivation, sense making or knowledge demand (Mettes, Pilot, & Roossink, 1981; Vermunt & Verloop, 1999). In the third column from the left in Table 1, prescriptive design guidelines on how to render complex, multifaceted, authentic scientific practices into contexts for learning in science education are described. In line with CHAT, the design guidelines describe learning tasks to be conducted by students, mediated by selected artefacts from the reflected authentic scientific practice.

Table 1. Activity-based instructional framework for the transformation of authentic modelling practices into contexts.

Learning phases	Pedagogical functions (PFs)	Design guidelines
I. Orient towards and connect with the practice: - Contextual bounds - Subjects, community, objects	PF_a: Evoke motivation to study the practice PF_b: Connect to the prior conceptual knowledge base PF_c: Connect to the prior procedural knowledge base PF_d: Evoke motivation to study exemplary problems or questions	i. Let students outline and schematise the issue at hand to activate students’ prior knowledge base (PF_b; PF_c). ii. Let students find out for themselves which major questions or problems exists in the authentic practice concerning the issue above, such that they become interested (PF_a; PF_d). iii. Let students analyze the method adopted in the authentic practice in response to the reported questions or problems, such that students become informed about the what, why and how experts work and what kind of solutions they strive for (PF_c). vi. Let students observe and conceptualise the exemplary modelling question or problem, such that they feel the need to obtain more (theoretical) knowledge to familiarise themselves with the issue at hand (Pf_b; PF_c; PF_d).
II. Focus on an exemplary problem or question: - Purpose of activity system - Writings and language used	PF_e: Make explicit and build on the prior conceptual knowledge base PF_f: Make explicit and build on the prior procedural knowledge base PF_g: Evoke an incentive to handle the exemplary problem or question	v. Let students study an assignment, related to the exemplary modelling question or problem posed in the authentic practice, to induce ownership among students (PF_g). vi. Let students analyse a worked-out analogous modelling question or problem posed in the authentic practice, such that students become informed about the activities to conduct and the knowledge and skills to learn to solve their exemplary question or problem (PF_e; PF_f). vii. Let students take notice of and orient towards the product to be delivered, related to an artefact that is used in the authentic practice and fits the exemplary modelling question or problem, such that they become aware of the criteria for assessment (PF_g).
III. Solve the exemplary problem or answer the question: - Activity structure, actions and operation - Theories, mental & physical tools	PF_h: Proceed through the sequence of activities and learn/apply knowledge until a solution or answer can be presented	viii. Let students think about different modelling approaches for the exemplary question or problem at hand, so that they become informed about the various ways to deal with the issue (PF_h). ix. Let students study real writings used in the authentic practice, such as articles, reports or manuals, such that they become acquainted with and understand the scientific theories related to the exemplary question or problem (PF_h). x. Let students conduct a series of actions, analogous to the modelling procedure experts performed in the authentic practice, such that students constantly have sight on why and what to do at every step in the trajectory (PF_h). xi. Let students carry out experiments, analyze the obtained empirical data and construct the model, such that they experience the working of the model, obtain insight in the advanced model features and underlying assumptions (PF_h). xii. Let student report on the progress to look ahead toward future activities related to the exemplary question or problem (PF_h).
IV. Evaluate and reflect on the findings: - System dynamics	PF_i: Evaluate the learned conceptual and procedural knowledge PF_j: Reflect on the procedural knowledge	xiii. Let students apply their constructed model in a real-world setting it was designed for, so that they feel the need to express and evaluate to what extent the exemplary question or problem has been solved (PF_i). xiv. Let students recall the different modelling approaches and let them reflect on the assumptions and estimations made and the possible effect of neglected variables so that they gain insight into the pros and cons of the applied modelling approach (PF_j) xv. Let students propose a modelling procedure for a similar question or problem posed in the authentic practice, such that students focus on the broader applicability of the learned conceptual and procedural knowledge (PF_i; PF_j).
V. Express the findings: - Means of communication	PF_k: Make explicit the learned conceptual and procedural knowledge	xvi. Let students report on the exemplary modelling question or problem worked on and hand in the product they have studied in learning phase II, so that students share and communicate about the learned conceptual and procedural knowledge (PF_k).

Below, the rationale underpinning the activity-based instructional framework is briefly described. The activity-based instructional framework strives to support educational designers to develop teaching materials and setting up learning environments that engages students in real-world societal issues embedded in the authentic scientific practices at hand. In terms of the context models of Gilbert (2006), this can be interpreted in terms of a setting, behavioural environment, specific language and extra-situational background knowledge. In designing learning environments that engages students in issues posed in authentic scientific practices,, we need to account for significant differences between experts, who in general are well-informed in the field in which they are employed, and students, who lack basic affinity and essential background information. In addition, the school environment is completely different from the environments in which experts work, both in aims, cultural role and function in society. In short: what is authentic for experts is not equally authentic for the students. Thus, one of the first stages in transforming authentic scientific practices is a careful analysis of the attributes which are already known and mastered by students, and the attributes which are within the ‘zone of proximal development’ of students. Using this information, students need to be introduced to the authentic practice such that object-related motives for carrying out an activity will arise.

In general, experts have clear content-related motives to go from one action to the next, inspired by relevant background information on the modelling issue. The experts’ chain of actions provides a basic outline for the sequence of teaching-learning tasks. However, the challenge for educational designers is to construct a sequence of learning tasks such that students (1) experience coherency between the different tasks (each task builds on the previous one and prepares the next one) and (2) are able to give meaning to each task to conduct, i.e. indicate why the task is needed to arrive at an answer or solution for the problem posed (Klaassen, 1995; Lijnse & Klaassen, 2004). Finally, using authentic scientific practices as contexts for learning, it is tempting to regard the experts’ mastered knowledge and skills as intended learning outcomes for students. However, while some of what the experts do is very specific for their work and is best taught by ‘on-the-job’ training, there is also likely to be a core of generic content which is common to all scientific practices within a given domain (Gott, Duggan, & Johnson, 1999). Educational designers need to identify the generic core content within a particular authentic scientific practice. Following, during and after their learning process students should be given opportunities to evaluate and reflect on this core generic content.

Instructional framework for scaffolding educational design activities

Teachers are considered the most important agents in shaping a new curriculum and bringing about change in educational practice. Researchers and policy makers increasingly advocate having teachers to participate in the design of innovative teaching materials (Bulte & Seller, 2011; Magnusson, Krajcik, & Borko, 1999; Shulman, 1987; Stolk, Bulte, De Jong, & Pilot, 2016). These studies have identified a number of conditions for involving teachers in educational design, such as the importance of working with a group of teachers to enhance teachers’ ability to work collaboratively, sufficient time for reflection on the design process, and access to relevant information and expertise during the design process to enable teachers to make well informed and argued decisions (Guskey, 2000). As for the latter, instructional frameworks are regarded as highly beneficial for helping teachers attend important components (Bybee et al., 2006; Edelson, 2001; Lawson, 1995). In addition, instructional frameworks can play an important role in social learning within a community, helping to provide a concrete representation and direction for teaching that can be reflected on, argued against, and applied in specific teaching situations (Schwarz & Gwekwerere, 2007).

An instructional framework directs, guides and provides an outlook to educational design, for which we apply Gal’perin’s theory on learning (Talyzina, 1973). That is, using the instructional framework for the guidance of the teachers’ design, three distinct phases provide the required outlook, namely (1) orientation on the activity, (2) carrying out a sequence of actions and (3) reflection on the performance. The quality of the first phase, namely orientation on the activity, is emphasised by Gal’perin, because it outlines the conditions which are objectively necessary to perform the activity successfully. As described by Arievitch and Haenen (2005, p. 162)

To enhance the learners potential to learn in the ZPD (zone of proximal development), Galperin focussed on improving the qualities of their orienting activity within their stepwise teaching-learning procedure.

An instructional framework as part of the orientation phase should contain all information necessary for a perfect performance of the educational design process, such as the goal of the design activity, the composition of all action links, the conditions in which the action can and cannot be performed.

However, the quality of the orientation phase is subject to debate for activities that are complex in nature, ask for creativity and/or involve problem solving aspects. Several studies have investigated the set-up and filling-in of the orientation phase, in domains such as handwriting, calculus, language and thermodynamics (Mettes et al., 1981). Curriculum design can be typified as an activity which evokes, among others, creativity and allows for multiple routes and approaches (Stolk, Bulte, De Jong, & Pilot, 2009b). In addition, the curriculum designer must be able to estimate whether the educational design in the classroom will function as expected in classroom. Regarding instructional frameworks, some key aspects are what kind of information should be delivered and how to ensure sufficient guidance whilst at the same time leave space for the designers own ideas and plans. Instructional frameworks should balance a number of criteria to enable the user to perform the design activity in sufficient quality. According to Mettes and Pilot (1980), the criteria can be ordered in two sets, namely (1) related to the nature of the framework, such as the completeness, generality and form of presentation, and (2) related to the practical feasibility, such as instructiveness and acceptance. In this study we focussed on three criteria, namely completeness, instructiveness and appreciation, which are briefly elaborated below.

1. The heuristics provided by the instructional framework have to be as complete as possible from the perception of the educational designer. Gal’perin distinguishes four components with respect to completeness, namely (1) explicating the aim of the activity, (2) explicating the sequence of actions, (3) explicating the resources and objects that are used as tools and (4) explicating the way a check is organised. However, an instructional framework for curriculum design cannot be complete, as it involves creativity and argued heuristic decisions. Related to the activity-based instructional framework, this comes down to identification of possible missing information, either in the learning phases, pedagogical functions or design guidelines. In addition, it is needed to investigate to what extent the framework helps the designer in selecting artefacts from the authentic practice at hand to be used in an educational environment. Finally, the fourth component is focussed on the extent the framework can be used as a checklist by the designer for self-control and reflection on own decisions.

2. In order to provide guidance to the design actions, the instructional framework must be as instructive as possible, i.e. well understood by the educational designer. The guidelines in the activity-based instructional framework should be formulated such that they support the designer to act according to the nature of CHAT. In addition, It is worthwhile to investigate whether the framework builds on the designers prior design expertise and extents their abilities to design context-based curriculum units.

3. The instructional framework should be appreciated by the educational designers. This means that the users should accept the guidance provided by the framework and the framework should fit their role as curriculum designer (Stolk, Bulte, De Jong, & Pilot, 2009a). The framework should not be perceived by the users as a ‘fixed tension’ forcing them to do all kinds of design actions in prescribed order, but be experienced as a valuable design tool providing suggestions and new views on how to operationalise CHAT in classroom practice.

Scope

This project is part of a larger research programme on the use of authentic scientific practices as contexts for learning in pre-academic chemistry education. In the previous studies, two practices were selected as feasible: ‘Modelling drinking water treatment’ and ‘Modelling human exposure and uptake of chemicals from consumer products’ (Prins, Bulte, Van Driel, & Pilot, 2009). Next, we transformed the practice ‘Modelling drinking water treatment’ into a context for learning that was applied in classrooms. The curriculum unit fostered students’ epistemic views on models and modelling in this particular practice (Prins, Bulte, & Pilot, 2011). During the research cycles we identified major design decisions, collected teachers’ and students’ experiences and conceptualised the findings in an activity-based instructional framework (Prins et al., 2016). In the current study, the practice ‘Modelling human exposure and uptake of chemicals from consumer products’ is transformed into a context for learning. The aim is to gain insight into the heuristic value provided by the activity-based instructional framework from the perspective of chemistry teachers as principle designers of the curriculum unit. The heuristic value is captured on three criteria, namely completeness, instructiveness and appreciation. The central research question addressed here is: To what extent does the activity-based instructional framework provides heuristic guidance for transforming an authentic scientific modelling practice into a context for pre-university chemistry education?

Methods

In this section we first present an overview of the authentic practice ‘Modelling human exposure and uptake of chemicals from consumer products’. Next, we focus on the research design, participants, the procedure, data collection and analysis in this study.

Authentic practice ‘modelling human exposure and uptake of chemicals from consumer products’

The authentic scientific practice at hand was ‘Modelling human exposure and uptake of chemicals from consumer products’, selected as suitable for use as context in chemistry education. The authentic practice ‘Modelling human exposure and uptake of chemicals from consumer products’ has been studied in detail in our previous study (Prins et al., 2008). This practice is aimed at developing models to describe exposure and uptake of hazardous chemicals from consumer products, and to assist in conducting a quantitative risk assessment.

Motives for modelling human exposure and uptake

There is a wide diversity of consumer products, ranging from shoe polish to detergents and pesticides that may contain hazardous chemicals. Consumers use all kinds of products for their personal convenience on a daily basis. In the Netherlands, the manufacturers themselves are responsible for the safety of their products, for which they use different systems. A commonly used method is expert judgement. However, when a product is encountered with questionable health risks, a quantitative judgement about the actual human health risks is also needed. For such assessment, one needs to calculate the total uptake of potentially hazardous chemicals from consumer products, based on detailed information on the composition of the product itself and on the exposure and contact routes. In response to this need, the National Institute of Public Health and the Environment developed the ‘Consumer Exposure’ (CONSEXPO) tool (Van Veen, 2001) to be able to calculate exposure and uptake of chemicals from consumer products, and to assist in conducting a quantitative risk assessment.

Content knowledge and modelling procedure involved

As may be clear from the above description, the CONSEXPO tool comprises a wide diversity of consumer products, exposure and contact routes, and mathematical models. Prior to transforming this practice into a context for learning, we decided to reduce the complexity (Prins et al., 2009) by focussing merely on the uptake of chemicals from consumer products through the contact route ‘mouth’. For the contact route ‘mouth’ several physical models are available, like single ingestion and leaching from product. In these models E is the amount of the compound taken up. Both models contain empirical parameters, like the initial leaching rate (R), parameters specific for the product at hand, such as the initial amount of compound (E₀), weight fraction (w_f), surface (A) and volume (V), and parameters related to type of use, like amount of product (q), dilution (D) and duration (t). The main content knowledge involved and the modelling procedure and are shown in Figure 1.

Figure 1. The modelling procedure and content knowledge in the authentic scientific practice ‘Modelling human exposure and uptake of chemicals from consumer products’. Arrows indicate the direction of the modelling process.

Procedure & participants

Six chemistry teachers (indicated T1 till T6) participated in the transformation of the authentic practice ‘Modelling human exposure and uptake of chemicals from consumer products’ into a context for learning. Each one of the teachers had over 10 years’ experience in secondary chemistry education, from grade 8 to grade 12. All six teachers participated in earlier phases of this research project in which the authentic practice ‘Modelling drinking water treatment’ was transformed into a context for learning and subsequently enacted in classroom. The teachers, therefore, were well informed about CHAT. The teachers came together in three meetings of three hours each, in which the authentic practice at hand was elaborated and the instructional framework was used to transform the practice into a context for learning. Given the purpose of this study, the data collected are essentially qualitative.

In meeting 1, the participants were informed about the authentic scientific practice at hand and familiarised oneself with the activity-based instructional framework (depicted in Table 1). The participants studied the motives and purposes, the modelling procedure and the content knowledge of the authentic practice ‘Modelling human exposure and uptake of chemicals from consumer products’. After the first meeting, all teachers individually studied the received information and transformed the authentic practice ‘Modelling human exposure and uptake of chemicals from consumer products’ into a context for learning.

In meeting 2, the six teachers were paired. Teachers T1 and T2 formed pair I, teachers T3 and T4 pair II and teachers T5 and T6 pair III, Each pair outlined a curriculum unit, guided by the activity-based instructional framework. The discussions of pairs at work were audio-taped. At the end of the second meeting, three outlines for a curriculum unit were available. During the design activities, each pair captured the usage of the components of the activity-based instructional framework in a logbook. The three outlines units were brought back to the teachers in the third meeting.

In meeting 3, the teachers first discussed the three outlines and compared the pedagogical decisions made by each pair. Subsequently, they designed a preliminary curriculum unit based on the outlines, again guided by the activity-based framework. This design task prepared for reflection among the participants on the guidance provided by the framework. Finally, a focus group interview, chaired by the first author, was organised to reflect on the heuristic value of the framework. The starting questions of the group interview are listed in Table 2. The plenary discussion was audio-taped.

Table 2. Questions to start the semi-structured group interview.

1. Please reflect on the completeness of the activity-based instructional framework. Please take into consideration the three components, i.e. learning phases, pedagogical functions and the design guidelines.

a. Do you ‘lack’ any information and/or clues?   b. Did you use the framework generally in a prescribed manner or as a tool for checking?   c. To what extent do the design guidelines support in selecting artefacts from the authentic practice?

2. Please reflect on the instructiveness of the activity-based instructional framework Please take into consideration the three components, i.e. learning phases, pedagogical functions and the design guidelines.

a. Was the meaning of the components clear?   b. Do the heuristics provided by the framework complied with your view on CHAT?   c. To what extent is the framework aligned with your design experiences?

3. Please reflect on your appreciation of the activity-based instructional framework

a. Do you consider the framework a helpful design tool?   b. Were you satisfied designing a curriculum unit guided by the framework?   c. To what extent does the framework foster or hinder your design activities?

4. Do you have any suggestions or remarks, not mentioned before, regarding the activity-based instructional framework?

Data collection & analysis

The collected data sources are (1) three written outlines of curriculum units, including logbooks of the pairs summarising the usage of components of the activity-based instructional framework, (2) audio-taped conversations of the pairs at work and (3) audio-taped focus group interview on the guidance provided by the instructional framework. The audio-taped conversations and interview were transcribed verbatim. The data was analysed from an interpretative perspective (Smith, 1995).

Based on the logbooks, the first author of this paper counted the usage of the design guidelines i – xvi (see Table 1) by each pair. Next, the first author analysed the conversations of the pairs to reveal information on how the pedagogical functions and design guidelines were interpreted. The group interview was analysed by two researchers independently (first author and a researcher in the department). First, all statements regarding the completeness, instructiveness and/or appreciation were selected and interpreted. Second, the interpretations of the researchers were compared. Differences in interpretations were discussed until consensus was reached. Finally, all findings and results were discussed by the complete research team (three authors of this paper).

Results

Below, we report on the heuristic value of the activity-based instructional framework, i.e. the criteria of completeness, instructiveness and appreciation. The valuations of the instructional framework are based on the outlines and curriculum unit designed by the teachers. In Appendix A the designed preliminary curriculum unit is presented.

Criterion completeness

To assess the level of completeness we identified:

• whether or not the learning phases, pedagogical functions and/or design guidelines have been implemented;

• use of the framework, i.e. as a design tool and/or as an instrument for check;

• support for selecting relevant artefacts from the authentic practice.

The group interview revealed that all of the pairs were confident about the sequence and filling in of the five learning phases (see Table 1). The teachers unanimously reported that the sequence of learning phases was largely according to their view of the learning trajectory of students. They also reported that the learning phases helped them in deciding which artefacts of the authentic practice to select. The teachers reported that they did not miss any information regarding the learning phases. The learning phases were predominantly followed as prescribed. Teachers started with thinking about the first learning phase, and then the following four phases in sequence. After having completed the fifth learning phase, teachers reported to revisit each learning phase to align planned activities for students and to plan for content knowledge to be delivered (just-in-time) to students. Regarding the pedagogical functions, the teachers reported that this component of the framework has been used the least often (compared to the learning phases and design guidelines). The pedagogical functions were regarded helpful to check whether all learning objectives, such as motivation, sense making or knowledge demand, have been addressed. Regarding the design guidelines, the teachers reported that they actually did not miss specific guidelines, but that they constructed learning activities that could not be linked to any design guideline. While designing the curriculum unit, the teachers reported that the design guidelines brought them to rethink decisions and consider alternatives. The analysis of the three outlines revealed insight in the implementation of the design guidelines by each pair. Pair I suggested to start with an orientation on the production process of consumer products (design guideline i), followed by an introduction of the Dutch governmental institute, Voedsel & Waren Autoriteit (VWA), responsible for risk assessment and public communication regarding products with questionable health risks (design guideline ii). The pair suggested to let students orientate themselves on the VWA, as exemplified by the following statement.

T1: … because the task of VWA is stated clearly on their website. The employees working [there] have three major tasks: supervision, risk assessment of new and/or suspected products and communication about health risks. Regardless of the exact type of products, you would like students to perform a risk assessment … 

Next, pair I decided to pick the release of dyes from the tops of water bottles, which are used daily by students, as an example problem (design guideline iv). Students should formulate a modelling procedure for determining the total uptake of dyes from the tops of water bottles (design guideline iii). The pair proposed to (1) discuss in class the formulated modelling procedures, (2) make an inventory of empirical data to be collected and (3) point out the type of end product to be delivered by students (design guideline vii). Pair I planned a demonstration in class to visualise the leaching out of chemicals, to inform students about the what and how to do in the lessons to come (design guideline iv), and decided to use an analogous problem to give students an idea about the type of activities to conduct (design guideline vi). For this, an already written risk assessment for another type of consumer product with a different contact route was proposed. Pair I used the general procedure followed by experts as the backbone of the sequence of students’ activities (design guideline x), as indicated by the statement below.

T1: … you can see that they [experts] analyse the release [of chemicals] followed by the actual harmfulness of the chemicals, the exposure and finally the actual risk assessment and conclusions. And this is eventually also what we expect students to do … 

Pair I examined the modelling procedure with special emphasis on the role and position of the experimental part in the sequence from the students’ perspective. From this, a chain of motives was proposed (design guideline xi and xvi), as exemplified by the statement below:

T2: … the order should be (1) clarify need for modelling, (2) focus on contact routes, (3) study available models describing contact routes and (4) conduct experiments to collect empirical data.

Teacher pair II, instead, decided to start with focussing students on the potentially hazardous chemicals in non-food products by means of (1) newspaper items, (2) internet search and (3) label analysis of some consumer products (design guideline ii). By reading, comparing and discussing products with questionable health risks, it was expected that students would come to ask themselves ‘Who is responsible of the health safety of the products?’ (design guideline iii). As a response to this students’ question, pair II suggested to introduce the governmental organisations controlling and/or authorising the health safety of non-food products, as well as the basic working procedure applied. The experts’ modelling procedure was taken as the frame for outlining the sequence of activities (design guideline x). Pair II selected the leaching of phthalates as an example problem, to be visualised in class by the leaching of dyes (design guideline v). The leaching of dyes was thus considered as a ‘model’ for the leaching of phthalates. Pair II considered it important to demonstrate to students the leaching of dyes (design guideline iv). To evoke a modelling procedure among students, pair II suggested orientating students on an analogous example dealing with another type of consumer product, such as toothpaste (design guideline vi). The analogous example should be presented such that students would easily identify the major steps in the procedure. After students would have collected all the (empirical) data, pair II proposed to evaluate in class the (1) quality of the gathered results for a risk assessment, (2) limitations of the employed model and (3) followed modelling procedure (design guideline xii). To keep track on the knowledge involved, pair II decided to let students construct a list of concepts as they went along during the teaching-learning process (design guideline xvi).

Teacher pair III decided to start with an orientation on the various exposure routes, and to represent the routes schematically (design guideline i). Pair III appointed students in the role of a manufacturer with the task of writing an allowance report for a new administration route (design guidelines v and vii), exemplified by the statement below.

T5: … let’s position students in the role of a manufacturer who would like to introduce a new administration route on the market. Preceding such introduction, the new administration route should be argued, empirically tested and justified. The specifications should be known ..

Students were to be given an assignment to ‘develop and investigate a new administration route for medicines for humans’ (design guideline v). The procedure to follow (as outlined in Figure 1) was considered in line with students’ common sense notions (design guideline x). Pair III considered it necessary to expose students to the different actors involved, such as the manufacturers, experts, civil servants and researchers (design guideline iii). Pair III planned a stage in which students orientate themselves on the procedure to follow for their example problem (design guideline vi). For this they suggested using a worked-out analogous problem (design guideline viii): a report summarising the findings concerning the release of phthalates out of personal decoration. It was emphasised that the modelling approach in both the example problem and the analogous problem should be the same on a conceptual level. To give students a view of the expected end product, pair III discussed the opportunities to bring in as teaching material an allowance report dealing with another administration route (design guideline ix). After having conducted all the experimental work and studied all knowledge, students were expected to be able to evaluate their findings (design guideline xiii). This should motivate students to make explicit their conclusions (write allowance report), reflect on the procedure (limitations and uncertainties) and formulate future research (design guidelines xiv and xvi).

Taken together, in Table 3 an overview of the usage of the design guidelines per teacher pair is presented .

Table 3. The usage of the design guidelines in the activity-based instructional framework based on the teachers’ logbooks.

Design guidelines	Used (Yes | No)			Major findings
	Pair I	Pair II	Pair III
i	Y	N	Y	Design guidelines in learning phases I and II (i till vii) more often used than the design guidelines in learning phases III, IV and V (viii till xvi). Design guidelines focussed on evoking evaluation and reflection in students (viii, xiii, xiv and xv) hardly used. All pairs used an analogous problem as advanced organiser (design guideline vi). The experts’ modelling procedure is regarded a valuable design guideline for outlining a sequence of teaching-learning activities (design guideline x). All pairs used design guideline xvi in combination with design guideline v, focussed on the end-product for students to deliver.
ii	Y	Y	N
iii	Y	Y	Y
iv	Y	Y	N
v	Y	Y	Y
vi	Y	Y	Y
vii	Y	N	Y
viii	N	N	Y
ix	N	N	Y
x	Y	Y	Y
xi	Y	Y	Y
xii	N	Y	N
xiii	N	N	Y
xiv	N	N	Y
xv	N	N	N
Xvi	Y	Y	Y

The results show that all design guidelines are used, although not necessarily by all pairs. The design guidelines in learning phase I were used intensively by all pairs. This phase predominantly contains guidelines for introducing students in the practice and motivating them to zoom in on problems posed. All pairs reported the guidelines made them think about ways to engage students for the practice. In addition, all pairs adopted design guideline vi, suggesting to use an worked-out analogous problem as advanced organiser, as well as guideline x, which is focussed on using the experts’ modelling procedure as backbone for a series of modelling actions for students to conduct. On the other hand, the analysis revealed that the design guidelines which focussed on evoking reflection in students (viii, xiii, xiv and xv) were hardly used.

During the group interview, all six teachers reported that the framework helped in selecting essential elements from the authentic practice to use in educational environment. The framework focussed teachers on the primary purpose and motives embedded within the practice and the type of knowledge and modelling skills used by the experts.

Criterion instructiveness

To assess the level of instructiveness, we focussed on:

• the extent to which the components of the framework are clear and understood;

• the extent to which the framework complies with teachers’ interpretations of CHAT;

• the extent to which the framework is aligned with teachers’ design experiences.

The learning phases were regarded clear to all teachers. As for the pedagogical functions, two teachers (T4 and T6) were of opinion that categorising the functions per learning phase was unsuited. They claimed that all pedagogical functions should be fulfilled to some extent in all learning phases. According to these two teachers, it is more about the degree of depth with which each function is addressed than the strict order. Regarding the design guidelines, the results show that the majority of the guidelines (11 out of 16) was clear and well understood by the teachers. Below we highlight some major findings based on the three outlines of the pairs as well as the group interview.

The design of the first learning phase (orientate on the practice) posed many design issues and choices, probably due to the variety of pedagogical effects to fulfil at the same time, e.g. evoke motivation, activate prior content and procedural knowledge in students. This is reflected to some extent in the different choices each pair made for introducing students in the authentic practice. However, there was consensus regarding the objectives of the first learning phase, as put forward by the teachers during the group interview:

• to make students aware that chemicals which are put into consumer products might also come out during use;

• to point out to students that some chemicals are necessary to give consumer products desirable properties;

• to rule out the ‘easy’ solution which students may come up with: ‘just don’t use the potential hazardous chemicals in consumer products’ or ‘use harmless alternatives’.

For the second learning phase of the curriculum unit, it was noteworthy that all pairs paid attention to select a suitable exemplary problem posed in the authentic practice for students to work on, as well as formulating an end product to be delivered by the students matching the exemplary problem (design guidelines v and vii). The studying of an analogous problem (design guideline vi), with the aim of identifying the type of knowledge to learn and activities to conduct by students was adopted by all the pairs. For the third learning phase, especially design guideline x, focussed on the experts’ modelling procedure, was used by all the pairs for outlining a sequence of teaching-learning activities. The statement below is indicative for teachers’ views on using the experts’ modelling procedure.

T4: … the method of the professionals … that is the main frame, also for me to understand [what exactly is going on] … not all is obvious [for students] … for instance … the contact routes and employed models … we need to design extra teaching-learning tasks to pay attention to this.

The guideline for using adapted authentic documents to communicate situated knowledge (design guideline ix) evoked discussion about which concepts students actually need to master to solve the example problem. Teacher pair III concentrated on outlining the relevant knowledge for students (design guideline xi):

• orientate on the model employed (What is the meaning of each parameter involved? How do we measure each parameter?);

• study the laboratory work (read through prescripts, consult literature, analyse data);

• study and formulate a contact scenario, summarising estimations about the type, frequency and duration of use;

• calculate the uptake with use of the model and contact scenario.

A point of discussion was the timing to bring in the models to be employed, and the background knowledge regarding contact routes and scenarios. Pair II discussed the benefits and disadvantages of (1) simply supply the employed models, or (2) deduce or construct a model themselves, as well as experiments to conduct, i.e. (1) provide laboratory prescripts (deduced from the authentic practice) or (2) let students design their own experiment (design guideline xi). The following statements are indicative for teachers’ arguments brought forward.

T4: These models seem to originate from theories about condensed matter … do we want students to learn how these models are realised, or do they have to learn the authentic modelling procedure? That is my question. You do not pick a model from some predefined list.

T3: … students should ask themselves ‘Which model is appropriate for use in this case?’. Afterwards, you [teacher] can clear up the model and discuss the origins in class. At the end [of the teaching-learning process] students evaluate the model employed: What are the limitations? … and maybe compare with the experts’ approach: What are the differences with our approach?

According to teachers’ remarks in their logbooks the following guidelines were insufficient clear:

• inducing a content-related motive for modelling an example problem by students themselves (design guideline iv);

• organising an evaluation and reflection on the modelling approach and procedure by students themselves (design guidelines (viii, xiii, xiv and xv).

Especially for the latter, all the teachers were of opinion that the guidelines for how to bring students to evaluate and reflect on the conducted modelling procedure themselves were insufficiently clear. Only pair III thought of ways to apply the model in a real-world setting (design guideline xiii) and to summarise the pros and cons of the applied modelling procedure (design guideline xiv), However, the specific outcome(s) of the evaluation and reflection stage was a major point of discussion. As for the last design guideline xvi, all the pairs stressed the importance of selecting an end-product matching the example problem.

In the focus group interview, the teachers reported that the framework did comply with their interpretation of CHAT. The teachers claimed that the framework brought them to pay attention to the social embedding of the practice, i.e. the relevant stakeholders. According to their own judgement, the framework complied with their prior design expertise.

Criterion appreciation

To assess the level of appreciation, we focussed on:

• the extent to which the framework was considered as a helpful design tool;

• the extent of satisfaction evoked by conducting design activities guided by the framework;

• fostering or hindering aspects regarding the design activities to be conducted.

In general, the instructional framework was highly appreciated by all participants. In the group interview the teachers emphasised the usefulness of the framework. The framework structured the ‘creative’ design process and focussed the teachers on essential learning objectives to take into account. One of the benefits brought forward by the teachers was that, because of the guidance by the framework, each of the three outlines had the same overall structure, thus facilitating comparison. In addition, because the framework prescribed a set of learning objectives to be addressed in sequence, the teachers said that it was relatively easy to check how and in what way the learning objectives were implemented in each outline. These two outcomes were said to facilitate the collaborative design approach.

No hindering aspects regarding design activities were reported, although the components from the framework were used in different ways and not all design guidelines were implemented by all pairs. A fostering aspect mentioned was the availability of in depth information about the specific authentic practice at hand, as well as some insight about students’ views on this practice. The teachers reported that the authentic practice is a powerful source of inspiration for outlining the curriculum unit, but also evokes many questions about what to keep, what to remove and what to modify.

Conclusion and discussion

The present study focussed on the heuristic value provided by the activity-based instructional framework in transforming the authentic scientific practice ‘Modelling human exposure and uptake of chemicals from consumer products’ into a context. The heuristic value was captured on three criteria: completeness, instructiveness and appreciation. The central research question addressed is ‘To what extent does the activity-based instructional framework provides heuristic guidance for transforming an authentic scientific modelling practice into a context for pre-university chemistry education?’. In this section we first summarise and reflect on the major conclusions. Secondly, we evaluate the employed procedure, reflect on some limitations and formulate future research.

The findings show that the activity-based instructional framework, in general, provided useful heuristic guidelines for the transformation of the authentic scientific practice into a context. The instructional framework was highly appreciated by all participants. The overall completeness was deemed high. The findings reveal that the five learning phases in the design framework comply to a large extent with teachers’ view on the general course of the teaching-learning process in class. Teachers retained to the general backbone and did not question the sequence of learning phases. The instructiveness, however, can be enhanced when it comes to incorporating more explicit guidelines for evoking evaluation and reflection among students, as well as suggestions to evoke students’ motives to become engaged in an example problem. One of the benefits of using an instructional framework is that the designer(s) start with focusing on the overall structure of a teaching-learning process, before going into details related to single, isolated learning activities. Such an intermediate step in the design process enables identification of key pedagogical decisions in the overall teaching-learning trajectory, which can be empirically investigated in latter stages.

The activity-based instructional framework appeared a valuable tool in the educational design process conducted by the teachers. Other valuable tools in the educational design process, besides the activity-based instructional framework, was the authentic practice itself as source of inspiration. These tools proved successful to empower the teachers for context-based curriculum design. Stolk, Bulte, De Jong, and Pilot (2012) have described a number of conditions and recommendations for engaging teachers in curriculum unit design, among which explicating teachers’ professional knowledge regarding curriculum unit design, delivery of relevant resources and tools for the designer, and the availability of a framework for curriculum unit design. In our study the resources and tools to engage teachers in curriculum unit design were delivered by the authentic practice, which was elaborated intensively in the first meeting. The activity-based instructional framework proved to connect to teachers’ educational design expertise, as well as and teachers’ interpretations of CHAT. According to the teachers, the framework proved successful in operationalising the underlying CHAT into concrete guidelines.

The employed procedure in this study (participatory design) functioned well. The role of the teachers as designers was clear at all stages. Many curriculum innovation projects emphasise the essential role of teachers as developers of innovative curriculum materials. At the same time, many projects struggle to find ways to involve teachers such that they can contribute in a valuable way. The procedure outlined in this study might serve as a model for effective co-design. Future research is needed to gain insight whether this collaborative design helps to reduce discrepancies between curriculum design and actual classroom environments (Könings, Brand-Gruwel, & Van Merriënboer, 2005; Könings, Van Zundert, Brand-Gruwel, & Van Merriënboer, 2007).

The results obtained in this study are subject to certain limitations. Firstly, it should be noted that this particular authentic practice was selected after a thorough evaluation and was well documented. The teachers could immediately focus on transforming the authentic practice into a context for learning, instead of figuring out what the practice is all about and revealing its essentials. Secondly, the presented activity-based instructional framework has only been used to transform authentic scientific practices in which modelling is the key-activity. The criterion of generality, i.e. using the instructional framework to transform other authentic scientific practices, either within the chemistry or broader science domain, needs to be studied. In addition, also other criteria need further elaboration, such as the form of presentation and practical feasibility. Thirdly, the participating teachers were well informed about CHAT, because of their involvement to this research project in earlier stages. For teachers who are not familiar with CHAT, it seems necessary to invest time to become acquainted with CHAT as well as the employed activity-based instructional framework.

This activity-based instructional framework provides a more detailed guidance to transform authentic practices into contexts for learning then many other frameworks discussed in the theoretical section. So far, this frameworks proved successful in designing a curriculum unit aligned with CHAT. From a curriculum perspective, however, it is needed to develop frameworks to transform other authentic scientific practices emphasising different kinds of activities next to modelling, such as production of foods and/or design of materials. Having available a collection of instructional frameworks aligned with CHAT, embodying different kind of activities commonly employed in science, enables research-informed, large scale curriculum innovation (Sevian & Bulte, 2015). This calls for well-tested, practical feasible and validated instructional frameworks, complying with teachers’ educational design expertise, in order to further develop and implement context-based curricula.

Acknowledgements

The authors wish to thank the Dutch chemistry teachers Rens Bijma (Griftland College, Soest), Wijnand Rietman (Het Streek, Ede), Jan de Vries (Oosterlicht College, Nieuwegein), Jeannine Acampo (St. Bonifatius College, Utrecht), Frans Teeuw (Koningin Wilhelmina College, Culemborg) and Sanne Spijker (ORS Lek & Linge, Culemborg) for their contribution to this research project.

Disclosure statement

No potential conflict of interest was reported by the authors.

ORCID

Gjalt T. Prins http://orcid.org/0000-0002-7041-567X

Astrid M.W. Bulte http://orcid.org/0000-0002-5097-081X

Albert Pilot http://orcid.org/0000-0003-2168-6825

Appendix A. Preliminary curriculum unit based on the authentic practice ‘Modelling human exposure and uptake of chemicals from consumer products’ designed by the teachers

Learning Phase	Description of teaching-learning activity	Considerations
Orient towards and connect with the practice: • Contextual bounds • Subjects, community, objects	1. Uptake of chemicals from consumer products. Examples: • phthalates in water from synthetic bottles; • dyes from synthetic materials; • preservatives in plastics; • nickel in jewellery; • cosmetics. Student activities: • Search for suspected consumer products; • Make overview of production process of suspected consumer products; • Find news items reporting on potentially harmful products.	• Pick examples that align with the ‘world as experienced’ by students. • Emphasise that certain chemical additives are needed to give the products desirable properties. • Additives give products desirable properties. • Legally set norms for chemicals, such as accepted daily intake (ADI).
	2. ‘Zoom in’ on actors involved Government institutes, manufacturers, consumers, etc. Student activities: • Describe the tasks and responsibilities of each actor concerning public health in relation to consumer products. • Describe the general stages in risk assessment and evaluate their pros and cons: ○ Expert judgement; ○ Spot check of product; ○ Quantitative research on occasion.	• General overview of actors involved in risk assessment. • Students should become aware that not all (single) product(s) can be tested.
	3. Conceptual analysis Visualise the problem: Student activities: • Think about what you need to know from the product, contact route and consumer in order to conduct a risk assessment.	• Activate students’ own pre-existing knowledge base. • Emphasise that on conceptual level the problems are similar, regardless the type of problem, contact route and consumer. • Use picture as ‘roadmap’ during teaching-learning process. • Recall in latter phases to induce evaluation and reflection.
	4. Present exemplary problem Conduct risk assessment concerning exposure and uptake of dyes from synthetic products. Contact route: swallow through mouth. Student activities: • Search for legally set norms (ADI) of the dyes; • Think about the modelling procedure to apply.	• Demonstrate the leaching of dyes in class.
Focus on an exemplary problem or question: • Purpose of activity system • Writings and language used	5. Study a worked-out analogous problem Bring in an authentic risk assessment, adapted for use in education. The risk assessment concerns another type of chemicals/products and contact routes (not swallow through mouth). Student activities: • Study the (adapted) risk assessment with aim to identify: o Type of knowledge to learn; o Sequence of modelling activities to conduct; o End product to deliver. • Start by writing risk assessment for own example problem (take over the basic structure).	• Build on students’ pre-existing knowledge base • Students’ gain clear sight of sequence of modelling activities to conduct. • Students learn to select the main points, also of value for their own example problem, and leave out the details. • In authentic practices it is common use to reflect on previously conducted work.
Solve the exemplary problem or answer the question: • Activity structure, actions and operation • Theories, mental & physical tools	6. Consumer product Students make a list of information needed on each consumer product: • Composition, especially dyes; • Contact surface; • Volume; • Weight. Student activities: • Scan labels of consumer products; • Search composition on internet/ask manufacturer.	• Corresponds with the first step in modelling procedure in authentic practice.
	7. Contact route Students make a list of information needed on the contact route ‘swallow through mouth’: • Mathematical formula; • Parameters to measure. Student activities: • Select proper mathematical formula from pre-formulated list; • Think over the meaning of each parameter and how to measure; • Study the theoretical foundation of the mathematical formula; • Practice application of the model by means of assignments.	• Corresponds with second step in modelling procedure in authentic practice. • Introduce the mathematical formula by means of an adapted authentic document summarising all available models per contact route.
	8. Consumer Students make a list of information needed on the consumer: • Age; • Frequency of use; • Duration of use. Student activities: • Describe the use of the product by a (average) consumer.	• Corresponds with third step in modelling procedure in authentic practice.
	9. Collect empirical data By means of laboratory work (prescripts) and literature: • Measure initial release rate R; • Measure other parameters involved. Student activities: • Study theory underlying the experimental methods; • Study the laboratory prescripts; • Conduct laboratory work, analyse the data and evaluate the results.	• Corresponds with third step in modelling procedure in authentic practice. • Supply additional information about laboratory methods. • Explicitly evaluate the results and discuss limitations and assumptions.
	10. Total uptake Combine all (empirical) data and calculate the total uptake. • Distinguish average use and intensive use (worst case). Student activities: • Calculate the total uptake of the dye for two types of use for different consumers.	• Corresponds with the fifth step in modelling procedure in authentic practice. • Discuss the results in class.
Evaluate and reflect on the findings: • System dynamics	11. Evaluate the results Evaluate the calculated total uptake on the aspects: • accuracy; • reliability; • validity; • limitations; • assumptions. Student activities: • Evaluate the quality of the results.	• Students gain sight of the advanced features of employed models.
	12. Compare with legally set norms Draw conclusion about the possible health risks by comparing the calculated total uptake with the legally set norms (ADI). Student activities: • Evaluate two scenarios: average use and intensive use (worst case).	• Corresponds with the sixth step in modelling procedure in authentic practice.
	13. Evaluate modelling procedure Evaluate each step in the modelling procedure followed: • Successful steps; • Possible improvements. Student activities: • Recommendation for future research; • Compare with the experts’ approach; • Propose an approach for other chemicals/contact routes/consumers based on your own experiences.	• Students realise that the applied modelling procedure is applicable to other (related) problems. • Students make explicit the main points in the modelling procedure.
Express the findings: • Means of communication	14. Write report Students make explicit their learning gain by writing a risk assessment concerning the uptake of dyes from synthetic consumer products. Student activities: • Write risk assessment according to format; • Advice for future research.	• Explicitly recall the basic format for writing a risk assessment.