Promoting Interactive Learning: A Classroom Exercise to Explore Foraging Strategies

Abstract

We describe a classroom exercise to allow students to explore foraging strategies in higher vertebrates. The exercise includes an initial interactive session in which students act as predators and are guided through foraging simulations, and a subsequent student-led session where classmates are employed as experimental subjects. Students rated the exercise, which utilises only cheap and widely available resources, significantly more highly than another more traditional module element in terms of development of both biological understanding and transferable skills for the workplace. As current trends are towards making tertiary level bioscience teaching more challenging and engaging, our experiences with this exercise support its introduction on a larger scale to undergraduate biology and ecology curricula.

Keywords:

• Cooperative learning
• classroom activity
• enquiry-based learning
• experimental learning
• foraging strategy
• predation
• ecology

Introduction

Students across all ages and ability levels frequently identify themselves as having attention problems when listening to lectures (Hanrahan, 1998) and lectures have been described as having among the lowest information retention rates of any teaching method (Wood, 2004). Demonstrations and simulations have an important role to play in tertiary level science teaching and there is evidence that increasing the level of student involvement in such lecture activities, for example by getting students to compare actual results to predictions (an example of interactive learning), can increase student interest, enjoyment and learning of underlying scientific concepts (Milner-Bolotin et al., 2007). Cooperative learning, where students work together in small groups towards a common goal, is important in the development of teamwork skills (Lobato et al., 2010). Even moderate shifts away from passive learning, towards more interactive and cooperative learning have been demonstrated to result in significantly higher student learning gains (Knight and Wood, 2005). In addition to academic knowledge, classroom activities can also be instrumental in helping students to develop a range of transferable skills highly valued by employers (Clarkeburn et al., 2000). Student emphasis is on a desire for teacher-centred learning (Virtanen and Lindblom-Ylänne, 2009), which is the most familiar form of learning to most undergraduates. However, current trends in university bioscience programmes are towards enquiry-based learning, a form of learning by discovery which embraces the Scientific Method and includes students designing and carrying out their own experimental strategy to test a model or hypothesis (Adams, 2009).

Here we describe a two-part classroom-based simulation exercise allowing students to become involved in examining foraging strategies in higher vertebrates. During the simulations, students play the role of predators and dried chick peas represent a novel prey item. The exercise consists of two sessions, the first of which uses interactive learning to guide students through timed foraging simulations which demonstrate the formation of a search image to a novel prey item and the concept of optimal foraging. This is followed by a student-led session in which groups of students are given sequential control of the class to conduct foraging experiments they have designed based on field studies on vertebrate species reported in the literature.

The Learning Experience

This exercise was part of a first-year (level 4) module in Ecology taken by students following various bachelor degree programmes at the Universidad Especialidades Espiritu Santo, Guayaquil, Ecuador. During the 2007–2008 academic year, a total of 115 students took part in the exercise. The exercise took place over two 1 hour 40 minute sessions. Materials used in both sessions, and instructions given to students in the first section, were trialled and honed using students registered for this and other relevant modules between 2005 and 2007.

In the first session, students formed small groups and were guided through a foraging simulation which involved each student transferring as many dried chick peas (representing a novel prey item) as possible using chop sticks (feeding apparatus) from a tray to a receptacle 30 cm away in a fixed period of time (two minutes). Sufficient chick peas (300) were provided to each student to ensure the transfer rate was not influenced by the decrease in the number of prey items in the tray during the simulation. Repeating the simulation five times with each individual reporting the number of chick peas transferred each time, provided valuable data for class discussion of the implications of prey switching and development of a search image. Students then repeated the simulations transferring only chick peas with a coloured spot (applied to 40% of the chick peas prior to the exercise using nail varnish). These data encouraged students to continue the prey switching discussion and also to consider foraging techniques and foraging efficiency. In the final part of the first session, different coloured spots were assigned different relative energy values (i.e. blue spot = 2, pink spot = 10, brown spot = 50). The rarer colours were given higher relative energy values. Groups were asked to devise an optimal foraging strategy and five simulations were carried out to test the strategies.

For the second session, which took place one week after the first, the small groups were asked to design a set of simulations using the basic chick pea and chop stick set up to investigate a particular aspect of foraging of their choice using their fellow classmates as experimental subjects. Students were encouraged to base their investigations around a report in a peer-reviewed journal of the foraging activities of any vertebrate species and to be as inventive as necessary to create suitable test conditions in the classroom. Each group was given 20 minutes of class time, sufficient to explain the conditions and to conduct five simulations. Assessment of the exercise was on the basis of a written report submitted two weeks after the second session based on the foraging results collected by the student’s own group.

An anonymous questionnaire completed at the end of the last taught session of the module consisted of seven statements and two open-ended questions for each of two exercises. Students were requested to rate their response to the statements on a scale of 1 (strongly disagree) to 5 (strongly agree) in a similar design to that used by Chang and Barufaldi (1999). The questionnaire was administered in Spanish. Translations of the statements and questions are shown in Appendix 1. The questionnaire was carried out in the last taught session of the module and students absent from the session were e-mailed the questionnaire in an attempt to reduce the effect of this on questionnaire validity.

The questionnaire was designed to compare student opinion on the foraging exercise (which was supported interactive learning), to an exercise on cetaceans (which was supported by passive learning). Students were asked to rate their agreement with the statements with respect to two pieces of assessed coursework; a write-up of the foraging exercise and an essay exercise based on humpback whales (Megaptera novaeangliae) in Ecuadorian waters. The essay exercise was based around two 1 hour 40-minute classroom sessions covering “An introduction to cetaceans” and “Humpback whale ecology”, both traditional passive learning sessions. The essay theme “Humpback whales in Ecuador” was assigned in the second of these sessions with a submission date two weeks after the second session. Both the foraging and the humpback whale assignments were supported by the same amount of classroom time. Each assignment contributed 30% towards the coursework component of the module, which itself contributed 50% to the overall module mark. For both assignments, students were required to consult and cite relevant scientific literature.

In the cetacean sessions, the students were required to listen and watch the materials presented in the form of PowerPoint slides and video clips. Students could raise their hands and ask questions, however, no specific interaction was required. In the first foraging session, all students were required to move chick peas using chopsticks and report their data to the class. They were also required to predict results, compare expected and actual results, and devise and test optimal foraging strategies. While group work was not explicitly prohibited for the essay exercise, all students appeared to work on the assignment individually. Group work was required for the foraging exercise. The educational approaches being compared can be described as learning about biology (cetacean exercise) and learning how to do biology (foraging exercise). A total of 89 students returned a completed questionnaire.

Results and Discussion

This exercise requires dried chick peas, chop sticks, nail varnish and student ingenuity, and the 115 students that took part proved to have the latter in abundance. All 23 student groups involved in this exercise during the 2007–2008 academic year arrived at the second session with a workable idea for their use of class time, a result due at least in part to the fact that the write-up of the activity constituted a mandatory piece of assessed coursework for the module. The ideas selected for testing by the groups displayed a wide range of adaptations to the original simulation set up and can be placed into three general categories:

1. Changing the availability of prey: A number of groups chose to change the abundance of different coloured chick peas, or introduce a new coloured chick pea. These simulations were designed to examine foraging responses to the natural temporal changes in the abundance of prey that can occur within and between seasons. As an example, one group flooded the foraging trays with chick peas of a high relative energy value during their simulations to examine subsequent changes in foraging strategies, based on observations reported for common seals (Phoca vitulina; Tollit et al., 1997).

2. Changing the background: Variously patterned and coloured paper sheets were placed behind the chick pea prey items to alter crypticity. For example, one group chose to examine the relationship between crypticity and scrounging which involved the introduction of an additional ‘transfer plate’ between the foraging tray and the final receptacle. Two chick peas had to be on the transfer plate before they were allowed to be moved to the final receptacle. Producers (defined as those searching for prey) had to share the chick peas being transferred from the transfer plate with Scroungers (defined as those waiting for the producers to find the prey), if a Scrounger was present at the transfer plate at the time of transfer. During simulations, individuals were free to switch between the Producer and Scrounger roles. In nutmeg manikins (Lonchura punctulata), increased crypticity of prey has been reported to reduce the number of group members actively searching for food (Barrette and Giraldeau, 2006) and using brown, spotted background sheets of paper, this was also demonstrated in the class simulations.

3. Introducing a higher predator: Groups came up with a variety of strategies to investigate the effects on foraging of the introduction of a top predator. For example, one group employed a single class member (‘the eagle’) to place stickers on participants’ backs. Each sticker in place at the end of a simulation represented a loss of 10 chick peas from the transferred total of that participant. Stickers could only be placed when the participant had their back to the eagle. The group videoed the simulations and subsequently calculated the distribution of time between vigilance and foraging for each participant. No significant difference was detected between the vigilance of male and female humans, unlike the findings for white-faced capuchins (Cebus capucinus; Rose and Fedigan, 1995).

When asked to respond to the statement “This exercise helped me to understand biological material”, 76.4% of questionnaire respondents agreed or strongly agreed with relation to the foraging exercise, compared to 34.8% for the essay exercise (Figure 1a). Rating the responses as 5 (strongly agree), 4 (agree), 3 (neutral), 2 (disagree) and 1 (strongly disagree), the foraging exercise scored significantly higher than the essay exercise on this statement (paired t (176) = −7.33, p < 0.001). This correlates well with the opinions of teaching staff as to the quality of answers to exam questions in the areas covered by the foraging exercise and the essay. Students also rated the foraging exercise significantly more highly than the essay exercise when considering development of skills they will need in the workplace. When asked to respond to the statement “This exercise developed skills I will need in employment”, 88.8% of respondents agreed or strongly agreed with relation to the foraging exercise, compared to 59.3% for the essay exercise (Figure 1b). Rating the responses as above, the foraging exercise again scored significantly higher than the essay exercise on this statement (paired t (176) = −6.19, p < 0.001).

The results suggest that students find exercises using interactive and cooperative learning beneficial in the classroom in terms of both subject understanding and transferable skills development. As the two exercises examined different areas of the module syllabus, it is possible that the results reflect a pre-existing level of interest in one area of the syllabus over another. In selecting the humpback whale coursework, an element that many students on previous delivery of this module have expressed particular interest in, we hoped to reduce this possibility. As students were comparing an individual activity (the essay) with a group activity (the foraging exercise), it would be interesting in future to examine how the students rate the foraging exercise against other group activities. This would help determine the contribution to the success of the foraging exercise of the interactive learning in the first session and the cooperative learning in preparation for and delivery of the second session.

Figure 1 Responses to two questionnaire statements on students’ perceptions of exercises. a: ‘This exercise helped me to understand underlying biological material’. b: ‘This exercise developed skills I will need in employment’. n = 89. Significant differences observed between essay and foraging exercise responses. For statistical analyses, Strongly agree = 5, Agree = 4, Neutral = 3, Disagree = 2, Strongly disagree = 1.

Questionnaire comments on how to improve the foraging exercise included requests for more class time for preparation and further simulations, and the inclusion of a formal oral presentation session to hear all groups report their findings. General comments on the exercise suggested that students particularly enjoyed the freedom given to them when designing simulations. Eleven respondents made specific positive comments about how well groups had functioned during this activity, confirming the observations made during the exercise by teaching staff.

Several authors have published details of innovative interactive classroom activities designed to develop an understanding of optimal foraging including Lauer (2000) who uses the taste of jelly beans, and Ray (2010) who uses two types of dried beans and a hula hoop. The activity reported here differs from previously reported simulations in that the initial interactive activity is used as a base from which students are encouraged to design and conduct their own experiments to explore optimal foraging under different conditions. As students are required to work in small groups and use their fellow classmates to recreate a foraging experiment from a published paper, a deeper level of understanding of the study that has been conducted in the field is required than might be necessary for an essay writing exercise. Working in small groups encourages cooperative learning to reach the deeper level of understanding required. In a comment on the questionnaire, one student mentioned that a member of their group had not made any meaningful contribution to the work: a common complaint where group work is concerned. However, the same student then went on to say how sad the student who had not made a contribution looked when it was clear how successfully the group had conducted their class experiment without her help: “She really looked like she wished she had been part of it”. Students had clearly developed a strong sense of ownership of the experiments they designed, which may be an important factor in the higher scores they awarded this exercise for skill development and biological understanding when compared to an essay writing exercise.

We believe this exercise represents an economical yet effective classroom activity to help students develop a deeper understanding of a complex biological theme while concurrently gaining confidence in transferable skills such as working in groups, making oral presentations, summarising key issues clearly and coping under pressure, skills highly valued by employers. Peer group discussions have proved effective in encouraging high quality decision-making in other areas of biological science (Grace, 2009), and minimal teaching input while groups prepare for the second session may be an important factor in the student-evaluated success of the exercise. Student feedback, together with our experience, support introduction of such exercises on a larger scale to undergraduate biology and ecology curricula.

Appendix 1

• This exercise was enjoyable.

• This exercise developed skills I will need in employment.

• This exercise helped me develop the ability to cope under pressure.

• This exercise helped me develop the ability to summarize key issues clearly.

• This exercise helped me develop the ability to work in groups.

• This exercise helped me to develop the ability to make oral presentations.

• This exercise is something I would like to see more of in other modules.

• This exercise helped me to understand underlying biological material.

• What changes would you recommend to this exercise for next year’s students?

• Any other general comments about the exercise?

Acknowledgements

The authors wish to thank Luis Chavez, Universidad Espeicialidades Espiritu Santo, Guayaquil, Ecuador, for invaluable assistance with class scheduling and questionnaire administration.