Participatory design and needs assessment for a pressure-sensitive pen and mobile application (SensoGrip) for children with handwriting problems

Abstract

Purpose

Problems with handwriting are a common referral to occupational therapy in children and are often associated with inadequate pen grip and tip pressure. Technologies providing immediate feedback on applied forces are currently not available. Therefore, the aim was to identify user’s perspectives on the optimal functionality of a pressure-sensitive pen with an integrated feedback system.

Methods

To ensure that the product meets the requirements of the users, user needs of paediatric occupational therapists, elementary or special education teachers and children were collected in two focus groups and a children’s workshops before starting the technical development process. Focus group transcripts were analyzed and rephrased as user stories to identify user-centred requirements. In a second step, user stories were merged and ranked regarding importance and feasibility.

Results

120 user story requirements were generated from the focus groups and children’s workshops, indicating requirements regarding design and functionality for the pen and mobile application. Visual feedback, appropriate size and weight, customizability, ease of settings and usability of the pen were pivotal.

Conclusions

This study comprehensively researched the requirements for a device that may facilitate children in adjusting their handwriting pressure and can guide further research and evaluation.

IMPLICATIONS FOR REHABILITATION

• Description of a participatory design process for the development of a pressure-sensitive pen.

• Understand the needs of different stakeholders for an assistive device for children with handwriting difficulties.

• Inform the further development of a pressure-sensitive pen with immediate pressure-feedback.

Keywords:

• Handwriting
• pressure
• participatory design
• pen
• occupational therapy
• technology

Introduction

Handwriting is a complex task requiring cognitive, visual-perceptual, and fine-motor skills [1,2]. Mastering handwriting is essential for a child’s academic success while learning to write is challenging for many [3]. A Norwegian study showed that 27% of first-grade children have problems with handwriting [4]. A German survey of 2000 teachers reported that 60% of children have difficulties with sustained writing [5]. The improvement of handwriting is a widespread reason for referrals to paediatric occupational therapy [2,6]. The goal of handwriting instruction and remediation is that children acquire readable, fluent, and efficient individual handwriting without getting tired [5].

An essential fine motor component in writing is the adjustment of writing forces. Some children grip too hard whereas other have a loose grip [2]. Inadequate pressure control on the pen or paper can negatively influence the writing [7]. Traditional ways for therapists to remediate force adjustment is to use, e.g., direct instructions, shading exercises or carbon paper for feedback [2]. Immediate feedback and knowledge of correct performance are essential components of motor learning and motivation for children [8]. Therefore, we aimed to develop an immediate feedback system for finger and tip force, which is reasonable and motivating for children and can be used in therapy as well as in everyday situation. Some studies already investigated finger pressure (pressure applied by the fingers to the barrel) and/or tip pressure (pressure of the pen onto the writing surface) while writing [5,7,9–14]. As measuring writing forces is a complex task, research groups developed these systems with special pens and tablets for research purposes and lab situations. A research group in Canada [7,10,15] used a graphic tablet and a special wired stylus. In the study of Lin et al [14] the children wrote with a wired sensor pen on paper. The measurement systems used in these studies are for assessment in labour situations only and cannot facilitate leaning. To the authors’ knowledge, only one writing measurement system can be used in daily occupational therapy practice, namely the ErgoPen^® from Stabilo^® [16] but it is for assessment only. We are aware of one feedback system for this purpose: a peripheral bio-feedback with electrodes attached to the forearm and upper arm [17] and therefore also using a complex apparatus and cables to measure the muscle activity, but not the forces applied on the pen or paper and not applicable at home or at school. A meta-analysis revealed promising results for technology-based interventions to improve children’s handwriting [18], questioning if technology could also influence handwriting pressure. In clinical situations therapists and teacher can identify children with are struggling with force adjustment, but there is still a lack of knowledge about the ideal or typical pressure for writing.

Therefore, our interdisciplinary study group intended to develop a pressure-sensitive pen with an integrated feedback system about applied forces on pen and paper that provides objective data and facilitates children in adjusting the pressure. To ensure that the product meets the requirements of later users, a participatory design process prior to the technical developmental process was applied.

The human-centered design process (HCD), as defined by the DIN EN ISO 9231-210 [19], is commonly used to ensure the user experience of a future product before and during development by involving all relevant stakeholders at the different stages of the process. It consists of four phases: (1) understand the context of use, (2) define the user requirements, (3) develop design solutions, and (4) evaluate design solutions.

In a first step, focus groups can help to understand the context of use and collect user needs before defining user requirements. Using focus groups as an interactive survey method, allows deep insights into the experiences and intentions of users in a particular situation [20]. Furthermore, design workshops [21] can be used as a specific method within the HCD phases two and three to involve users in designing a product that focuses on creating meaningful patient benefits. Within design workshops, future users develop a version of the product themselves that fits their personal needs. Often this method is implemented for early prototyping of tangible objects using workshop materials, such as cardboard, modelling materials, or LEGO bricks [22,23]. Within a healthcare context, design workshops allow future users to bring in their perspectives by relating to their individual health needs [24,25].

The study presented in this paper, aimed to gather user requirements for a pressure-sensitive pen with an integrated feedback system.

Methods

Participatory design workshops and in-depth needs assessments were conducted to engage the most relevant stakeholders in our study and set the requirements for a technical system containing a pressure-sensitive pen and an accompanying mobile application.

Based on two workshops with children, one interdisciplinary workshop with project members, one focus group with paediatric occupational therapists and one focus group with elementary and special education teachers, requirements for the so called SensoGrip system were derived.

Participants

In the context of a children’s university day for children of the fourth grade, two design workshops in a classroom at the FH Campus Wien, University of Applied Sciences, were conducted. Twenty-three children, aged nine or ten years (10 male, 13 female), participated in the workshops. Additionally, seven members of the SensoGrip project team (two occupational therapists, one sociologist, one specialist in embedded systems, one specialist in medical computing, and two experts in high-tech manufacturing) participated in a design workshop to brainstorm design ideas for a pressure-sensitive pen. Four non-project member occupational therapists (all female), working with children with handwriting difficulties, were recruited via social media and email to attend a focus group. Therapists were between 26 and 47 years old and had four to 12 years of experience in the paediatric field. Four teachers (one male, three female) were contacted directly based on a list of teachers from a previous project and took part in another focus group. They were between 25 and 33 years old and had between five and six years of working experience. One teacher did not provide information about age and working experience. Informed consents were signed by all therapists and teachers beforehand.

Procedure

Children’s design workshop

The workshop’s scope was to design a “perfect pen” using pens, paper, and coloured modelling clay to address specific design needs of the primary target group for the SensoGrip system. In phase one, children were invited to try out a variety of commercially available pens and to critically appraise how and why they liked them or not. Phase two aimed at drawing an individual “perfect” pen that also contained some sort of lamp or glowing functionality giving feedback of the applied forces. Finally, in phase three children were asked to craft the perfect pen with modelling clay (FIMO). In all phases notes and pictures were taken by the research team to document children’s preferences and dislikes. Children were additionally asked if they sometimes recognize any pain when writing with commercially available pens.

Interdisciplinary workshop

Based on the model of cognitive-behavioural game design [26] the project team gathered a variety of ideas regarding the implementation of feedback modalities and gamification elements. This model is a framework that incorporates Social Cognitive Theory and Multiple Intelligences with game design principles to create a game design blueprint for serious games. Non-functional prototypes to demonstrate design ideas were built with coloured modelling clay and design ideas were documented with text and pictures.

Focus groups with paediatric occupational therapists and teachers

Due to the Covid-19 pandemic, the focus groups were held via Zoom as a videoconference. Based on a semi-structured guideline one researcher with experience in paediatric occupational therapy conducted the focus group interview. Two further researchers accompanied the focus group interview and took notes. The focus groups were audio and video recorded. The participants were given a short presentation of the project and its goals. Topics discussed were design of the pen, provision of pressure feedback, settings of the SensoGrip system, and assessment and evaluation report methods for the SensoGrip system. The participants were asked to share experiences, brainstorm ideas in terms of functionalities and design, and express important needs of therapists, teachers, and children with handwriting difficulties. The interview questions were for example “What do you think is important in terms of design of the pen? or “How should the children receive feedback about the applied pressure?”, “Which settings would you like to be able to adjust and where would you like to do it?”, “How should the measured pressure data be presented?”.

Data analysis

Design ideas of the children’s workshop and interdisciplinary workshop were reformulated as user stories. User stories are short stories describing the interaction between the user and the application as well as the context of use [27]. They follow the scheme of “As a… (role), I want… (goal), to… (benefit)”, for example “As a therapist, I want to see the finger and tip pressure data in a line graph on a tablet application, to assess the handwriting pressure within therapy”. By using a web-based ranking tool (www.forcerank.it) all project members conducted a priority ranking of the gathered user stories. Video and audio transcripts of the teachers’ and therapists’ focus group were transcribed fully verbatim, using pseudonyms for the participants based on the transcription rules of Kuckartz [28]. Non-verbal cues as nodding or head shaking were documented as consent, respectively disapproval. Laughing or hesitations were noted to put certain statements into context. The transcripts were imported into the data analysis software MAXQDA 2018 (www.maxqda.com) for further qualitative content analysis based on Kuckartz [28]. The data was analyzed by using a deductive coding scheme, based on the interview guideline. The deductive topics comprised: design and colour; shape; haptics; size and weight; mine; pressure feedback; settings—which; settings—how; and assessment and evaluation. Complementary inductive codes and subcodes for further structuring were developed (e.g., settings—synchronization). One researcher coded both transcripts and a second researcher reviewed the assigned codings. Based on the review, both researchers discussed the code assignment until consent was built. All codings were screened by three researchers for requirements of the SensoGrip system. If a requirement was expressed by a participant, the coding was reformulated as a user story. If applicable, single user stories with equivalent meaning were merged. Three researchers reviewed if all requirements that were expressed in the focus groups were transferred into user stories without loss. This list of requirements was uploaded to www.forcerank.it and structured into thirteen categories while combining it with the three highest-ranked user stories of the interdisciplinary workshop. Two participants of the therapists focus group, as well as the project members, made a final priority ranking of each category, resulting in a final list of requirements for the SensoGrip system.

Results

Children’s design workshop

Phase 1 of the participatory design process gave an insight in the context of use. Ten of the 23 participating children reported that they sometimes felt pain in their hand or fingers while writing. Children preferred pens that had a small diameter, good grip, and no grip moulds to ensure self-determined grip type. Most of them favoured pencils or roller pens over filler pens. It was mentioned that pens should not scratch over the paper while writing. Phase two resulted in a variety of “perfect pens” in different colours as well as lamps or lights on different parts of the pen (Figure 1). No agreement was reached whether a light should flash when the pressure was correct or if it should light up when the pressure was inadequate. Concerning the colour of the light, many personal preferences were mentioned and ranged from white to multiple colours.

Figure 1. Crafted pens from the children’s workshop.

Nine pen designs made of coloured clay by children.

Interdisciplinary workshop

Based on the Cognitive Behavioural Game Design Model [26] various design features and functionalities for the SensoGrip system were created (Table 1). Visual design ideas and ways of implementation of drafted features were crafted with modelling clay (Figure 2).

Figure 2. Crafted pens from the interdisciplinary workshop.

Seven pen designs with accessories made of coloured clay by project team members.

Table 1. Creative design and feature ideas from the interdisciplinary workshop according to the Cognitive Behavioural Game Design Model.

Graphics	Visualization of the pressure curve of the SensoGrip pen on a tablet Visualization could be shown in the context of a street. Correct pressure should be expressed as “staying on the street” without crossing the borders. Display an evaluation of the written text with colour-coding of low, middle, and high pressure in green, yellow and red. Display green, yellow or red LED on SensoGrip pen according to low, middle, and high pressure Display different smileys on the SensoGrip pen according to pressure Colour of the pencil should be gender-neutral Tablet app with animation that is controlled by the SensoGrip pen (e.g., maze that should be traversed by applying different pressures on the pen)
Music/sound	Sound output on the SensoGrip pen according to pressure (e.g., applause, music) Sound output volume depending on the pressure (e.g., high pressure—loud, low pressure—quiet) Sound output when pressure is correct over a predefined period (e.g., one beep after 10 s, two beeps after 20 s)
Physical movement	Small toy figure that vibrates when pressure is too high or correct (individual settings) SensoGrip pen vibrates when pressure is correct for a certain period
Humor	Funny sounds when pressure is too high (e.g., “ouch”, “boing”) Tablet application with toy figure that is becoming thicker or thinner according to applied pressure on SensoGrip pen Small toy figure that laughs or giggles when pressure on SensoGrip pen is correct
Space/positioning	All-round sensitive grip area
Narrative	Accompanying tablet app with a story mode with specific tasks for adjusting writing pressure Exercises with stories—what happens at high or low pressure
Logic/patterns	Display with rising or sinking pressure on a scale Several LEDs that light up according to pressure (e.g., one LED—low pressure, all LEDs—high pressure) Display on SensoGrip fills up with colour according to time of correct pressure applied
Nature	Leaves on SensoGrip pen illuminate one after another according to a period of correct pressure applied
Relationships/role models	Replaceable toy figures as pendants of the SensoGrip pen with individual settings for each child Accompanying story for exercises with SensoGrip pen with role model (e.g., “pen hero”)
Math/numbers	Visual display of applied pressure with digits on SensoGrip pen or external display or tablet app
Words/language	Feedback output about applied pressure in words (e.g., “a little less”, “much more”, “too high”) Sound output of a story that is read faster or slower according to higher or lower pressure
Personal reflection	Adjustable pressure range that is defined as correct SensoGrip pen or tablet app displays the amount of time SensoGrip was used Selectable smileys that give feedback about pressure according to the child’s preferences

Focus groups with paediatric occupational therapists and teachers

The findings of the focus groups were categorized into the following themes: pen design, provision of pressure feedback, settings of the SensoGrip system, assessment, and evaluation report method, as well as further requirements.

Pen design

Diameter, weight, and point of gravity

The SensoGrip pen should have a diameter that is suitable for a child’s hand. Therapists and teachers observed that a pen with a slightly increased diameter offers a better grip. It should not be too long to suit small hands. For a good sensation of the pen, it should have a balanced weight that prevents exhaustion but still offers enough sensory input. The centre of gravity should be towards the tip of the pen. It was mentioned that the SensoGrip pen must not be too different from a conventional pen to ensure the transferability of the acquired skills.

Grip area

The participants preferred interchangeable grip surfaces or two versions, one round-shaped and one triangle-shaped surface, to meet individual pen grips of children. The pressure-sensitive grip surface should be highlighted in colour to clearly distinguish it from the rest of the pen. A tactile or visual boundary towards the tip of the pen also might help to guide the fingers of the child in the right place. Developers should consider that children with handwriting difficulties might show a variety of grip styles. Therefore, the grip zone should be up to 7 cm long. Pens with grip moulds were considered not to be suitable for all children, still, it helps some of them to write with a functional grip. It should be noted that if grip moulds would be applied on the SensoGrip pen, they should not be too deep to prevent the distal interphalangeal joint from hyperextension. Therapists and teachers emphasized that a good grip on the surface must be ensured by rubber coating or small nubs. The pen should be of a neutral design, as the integrated technology already offers stimulative nature and overstimulation needs to be prevented. Most participants preferred grey, green, or blue colour shades while one therapist suggested a neon colour.

Mine

The participants felt that a pencil mine would be suitable for younger children and a roller pen mine for children at a higher age. If they had to decide for one of both options, all but one preferred the roller pen mine. The group discussed that pencil mines have the disadvantage of getting shorter with sharpening. Most importantly, the friction of the pen on the paper should ensure smooth writing. The mine should allow for producing thicker or thinner lines according to applied pressure on the paper. One therapist also mentioned that the sound of the mine on the paper should be considered as some children are sensitive to sound. Teachers also emphasized that the ink should be erasable and not sensitive to heat.

Provision of pressure feedback

Therapists agreed that grip pressure and tip pressure are both important parameters in children with handwriting problems. If combined feedback about both pressures (pen and tip pressure), both pressure values, or only one of them should be shown to the child, led to some discussion. Finally, they agreed that therapists should decide the feedback setting based on the individual requirements. Teachers preferred combined value feedback. Both groups agreed that showing both single values with two displays or outputs would be overwhelming and confusing to the child. Different modalities for the feedback were suggested: visual, auditory, and vibratory. The therapists preferred to choose the feedback modality for each child individually or they would decide for the visual feedback. Teachers rejected auditory feedback in the classroom as it might disturb other children. In other contexts, auditory feedback could be helpful. Positive feedback as reinforcement was clearly favoured over negative feedback by therapists while teachers were non-committal. Preferred colours for visual feedback varied from neutral light to signal lights in green, yellow, and red. A led should be positioned in the front part of the pen to prevent from losing sight of the written text when looking at the light. In the case of auditory feedback, individual sounds or texts could be recorded that serve the child’s needs. One example given by a therapist was that animal sounds could be connected to light or high pressure with the sound of a mouse or elephant, respectively. Another suggestion was that a melody is played when the correct pressure is applied and stops when the child should make pressure adjustments. Teachers thought of verbal and appraising feedback by the pen. Some participants said that vibration feedback could be added if good pressure was applied over a specific period to give an extra reinforcement, while others declined it because they thought it might negatively influence pen strokes.

Settings of the SensoGrip system

The participating therapists emphasized that it should be possible to set an individual range of target pressure for each child. They mentioned that also minor improvements must be recognized and fed back. This could be realized in an application, where the upper and lower limit of the desired pressure value can be set. Still, they wished there would also be generic settings based on standard values for age groups. Teachers felt that an occupational therapist primarily should set the parameters. The SensoGrip pen should have an on/off button and could also contain a setting dial for selecting different feedback modalities or other settings. Further settings should be realized on an external device like a tablet, smartphone, computer, or remote control with inconsistent preferences by the therapists. Considerations included which settings should be done on the external device and which should be located on the pen itself. Settings on the pen would interrupt the writing process but an external device otherwise could pull the attention of the child. In the case of more than one child using the SensoGrip pen, profiles should be implemented to allow individualized settings. Automatic identification of the person using the pen, for example by writing their name or a specific symbol, would be appreciated. Otherwise, it should be simple to switch profiles.

Assessment and evaluation report method

The therapists group felt that data from the SensoGrip pen should be automatically transferred and synchronized with the external device via Bluetooth, while teachers had a wire connection in mind. Both groups wished to see grip and tip pressure values separately and as a combined value in a graph. Additionally, a colour scheme based on traffic lights could highlight areas with low, middle, and high values. The participants emphasized that it was important to save data to compare values over the course of therapy sessions. An export function to add data or graphs to therapeutical reports would be helpful. Teachers also wanted to have access to writing pressure data of the child and preferred to see them on the computer and have the possibility to export or print them.

Further requirements

The battery of the SensoGrip pen should last at least 8–10 h to ensure functionality over a whole working day without the need for charging it between therapy sessions. It should be robust, as well as intuitive, and easy to use. Teachers emphasized that the SensoGrip pen should not cost more than 60 Euros. Sustainability aspects mentioned were replaceable mines and renting models. The teachers also suggested that there could be two versions of SensoGrip, one that only gives feedback while writing and another that can be used for detailed assessment and therapy.

User stories

The 394 coded segments of the qualitative analysis resulted in 120 user stories clustered in 13 categories. Each story has the schema: “As a… (role) I want… (goal) to… (benefit)”. The user stories with the highest priority ranking are listed in Table 2.

Table 2. User stories with the highest priority ranking.

Category	Number of user stories	Example (highest priority ranking)
Design and colour	10	As a therapist, I want the pressure-sensitive grip area of SensoGrip to be of contrasting colour, to show the child where to position the fingers for writing.
Shape	8	As a therapist, I want the shape of the grip area to be individualized (round-shaped, triangle-shaped, grip recess) to suit the preferences of each child.
Haptics	2	As a therapist, I want that the grip is medium soft and rubberized, to ensure a good and stable grip.
Size and weight	5	As a therapist, I want the SensoGrip pen to be comparable with a common pen in terms of size and weight, to ensure that children have enough tactile input (not too light) and don’t show fatigue (not too heavy).
Mine	9	As a therapist, I want an exchangeable pencil and roller pen mine, to meet age-specific needs.
Feedback	23	As a therapist, I want the SensoGrip to give visual feedback about the applied pressure in the front part of the pen, to make sure that children don’t lose sight of their written text.
Settings—general	6	As a therapist, I want that settings can be changed quickly to allow smooth application of SensoGrip in the therapy setting.
Settings—what?	5	As a therapist, I want to set an individual pressure feedback range, to ensure motivating feedback for children with various handwriting pressure severity.
Settings—on pen	6	As a therapist, I want that settings, which can be made directly on the pen do not negatively influence the weight of the pen, to prevent the child’s hand from fatigue.
Settings—how?	7	As a therapist, I want that individual settings can be made on an external device, such as a computer, tablet or smartphone, to make them independent from the pen.
Settings—synchronization	5	As a therapist, I want a wireless connection between the pen and the external device, so I do not need a cable.
Assessment and evaluation	22	As a therapist, I want to view pressure changes over a longer period of time, to get an impression of therapy progress.
Others	12	As a therapist, I want the usage of SensoGrip to be intuitive and easy, to reduce learning efforts.

Discussion

The aim of this study was to gather the requirements for a pressure-sensitive pen with an integrated feedback system. The human-centred design process allowed for gathering a comprehensive list of user story requirements. Perspectives and opinions were collected from important stakeholders of the target groups. Bringing together the views of children, therapists, and teachers, practice-focussed and client-centred requirements were collected. More and more published participatory design studies rely on the input of occupational therapists to design devices and apps intended for use in occupational therapy [29–31]. The results of this needs assessment study guide the further development of a pressure sensitive pen that can easily be used in therapy or school. Previous studies in this field used complex equipment as digitized tablets and wired or wireless writing utensils for pressure measurements that cannot be used in everyday practice [14,15].

The 120 user stories represent the manifold ideas and requirements and show that different stakeholders have partly coinciding but also divergent views. Occupational therapists mainly focussed on individualization to make the SensoGrip suitable for all children with handwriting difficulties in terms of shape, feedback, and settings. Teachers gave important input regarding the use in schools, focussing on reducing the risk of distracting other children in the classroom by the feedback feature of the pen. The children’s workshops revealed that a perfect pen is something individual, supporting the opinion of the occupational therapists. Consensus was found in terms of weight and size, the grip zone, and usability of the technical device. The weight and size of the pen should be comparable with a common pen, a requirement previously described by another research group [10]. The surface of the gripping zone should be made of non-slip material to facilitate an easy grip and avoid tense gripping because of a slippery surface. In our experience, many children are open to using special devices within therapy sessions but refuse to use them at school. To seek children’s acceptance might be one reason why stakeholders want the pen to look like a typical pen. Furthermore, a regular size, weight and gripping zone might facilitate the child’s typical pen grip, thus enabling the transfer of skills from the SensoGrip to a usual pen. Considering the implementation of necessary technology (e.g., sensor, battery, microprocessor), technical development is challenged.

A few limitations of our study should be mentioned. We included a relatively small sample of therapists and teachers. Their opinion does not necessarily represent the view of other therapists and teachers universally. Due to the COVID-19 pandemic, we conducted focus groups via videoconferencing, which may cause the risk of decreased participation due to an unfamiliar situation. The prioritization of the user stories was mainly done by project members and only accompanied by two independent occupational therapists, which might have promoted bias. Finally, we did not include children who receive occupational therapy services due to handwriting problems in the study process. Their point of view could differ from the opinion of the children that were interviewed and observed in the workshop. Further research must evaluate if the requirements addressed in this study as well as a resulting prototype match the needs of children with handwriting difficulties in a real-life setting. Feasibility studies, as well as studies with a representative sample of children with handwriting difficulties and their occupational therapists will have to examine the acceptance, usability and effectiveness of a future SensoGrip system prototype.

To our knowledge, this is the first study comprehensively researching the requirements for a device that may facilitate children in adjusting their handwriting pressure and can guide further development.

Conclusions

User story based requirements for the development of the SensoGrip system were gathered. We included occupational therapists’, teachers’, children’s, and engineering specialists’ ideas regarding the design, functionalities, feedback modalities, and settings of the system. Based on the identified needs, next steps will include a review of the technical feasibility of the favoured features, iterative prototyping, and evaluation.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by the City of Vienna, Magistratsabteilung 23, Austria.