Prioritising design features for companion robots aimed at older adults: Stakeholder survey ranking results

Hannah Bradwell1[0000-0002-9103-1069], Rhona Winnington2[0000-0002-6504-2856], Serge Thill3[0000-0003-1177-4119] and Ray B. Jones1[0000-0002-2963-3421]

1 EPIC Project, University of Plymouth, UK,

2 Department of Nursing, Auckland Univ. of Technology, NZ,

3 Donders Centre for Cognition, Radboud Univ. NL

Abstract. Background: Companion robots are social robots often resembling animals with potential wellbeing benefits for older adults. However, some such devices have failed possibly through inappropriate design. Method: Questionnaires were completed by 113 participants at nine health and care events. Participants were predominantly relevant professionals. Participants approached our interaction station, interacted with eight companion robots or alternatives, then completed questionnaires; ranking aesthetic, behaviour, technology, feel and interaction features and estimating affordable price. To obtain approximate ranking of features, we used a variant of the Condorcet method. Results: Features ranked highly were: interactive response to vocalisations and touch, huggable size, soft fur, variety of behaviours/sounds, realistic movements, eye contact with large cute eyes, being realistic, familiar, easy to use and possessing simulated warmth. Participants thought around £225 was affordable. Conclusion: We contribute priority features for stakeholders to inform future developments. Contrasting unfamiliar embodiment of some devices, stakeholders support familiar, realistic aesthetics. Implications of improved design include potentially enhanced acceptability, widespread adoption and more consistent wellbeing outcomes.

Introduction

Background

Health and social care (H&SC) is experiencing increasing pressure and demand worldwide, partly caused by aging and dementia [1,2]. Assistive robotics to support H&SC has gathered research interest [3], including robots for companionship. Among these, robot “pets” are robots designed congruent with animal aesthetics and behaviours [3]. The most well researched example is Paro, the robot seal [3]. Research has shown potential wellbeing benefits for older adults, people with dementia and stakeholders in their care, including; loneliness, depression, agitation and quality of life [4]. Other examples include NeCoRo, AIBO, iCat [5], and comparable ‘smart toys,’ such as the Joy for All (JfA) cats and dogs, which may also help improve older adult wellbeing [6].

Despite encouraging results and increasing interest, a number of devices in this sector have failed, and literature still lacks agreement on how to best design such robots. The importance of design in overall platform success cannot be overstated: appropriate design promotes acceptability among end users [7], while inappropriate design could lead to devices falling into disuse or not delivering expected benefits [8], proving costly to society. In this context, research previously demonstrated significant differences between older adults (as end-users) and roboticists (as developers) in perceptions towards suitable robot pet design for older people [9]. Aesthetic and behavioural features are likely to impact device acceptability and thus ultimately use [7]. As embodiment and morphology help establish social expectation, and bias the subsequent interaction [10]. Design and embodiment continues to be a research topic without definitive results.

The core contribution of this paper, therefore, is to help address this situation, through data collected with key stakeholders on optimum companion robot design, allowing prioritisation of features for future robot developments. The following section first provides an overview of current robot design research. The discordance in results between the studies highlights the importance of work of this kind.

Robot design research

A number of design features remain contested, including devices’ feel, emitted behaviour, aesthetics, technological sophistication and interaction type.

Feel. Heerink et al. [11] highlighted soft-fur as desirable, with care providers suggesting it as an important feature for robots aimed at older people. Fujita [12] also found hard-shelled, visually mechanical, robot dog Aibo, encouraged less interaction than a soft-shelled, plush toy. In contrast, aged care stakeholders previously suggested mechanical, anthropomorphic features were preferred, suggesting devices should be recognisably robotic [13]. Further demonstrating lack of clarity in optimum embodiment, Odetti et al. [14] reported good acceptability of Aibo, and Heerink et al. [11] demonstrated Pleo the plastic-encased dinosaur was kissed as much by older adults as the soft, furry Paro. Soft fur may also promote infantilisation concerns, with a resident’s relative previously reporting their father was not the type to cuddle soft-toys [15].

Related to feel, is inclusion of life simulation features, involuntary, physiological expressions potentially increasing perceptions of a device being alive [8] providing an additional tactile sensation. Older adults previously suggested breathing, purring, heartbeat and warmth as desirable features for robot pets [9]. There are alternative robots available with life-simulation, such as breathing robots, shown to decrease heartrate [16], but not standard on most robot pets, warranting exploration for future designs.

Behaviour. Jones et al. [17] explored the impact of aesthetics and behaviours, providing a Roomba robot vacuum with zoomorphic, dog-like behaviour. Results suggested behaviour and appearance did not impact participant ratings of performance, frustration, excitement or persistence. In previous work however, playful behaviours of Pleo created engagement, despite participant dislike of the plastic, unfamiliar embodiment [9]. Related to behaviour, is vocalisations used, a further feature without consensus. Previously, care providers noted appropriate sounds were important [11], although limited understanding of most appropriate emitted noise exists. Perhaps surprisingly, older adults previously reported interest in robot pets speaking human language [9]. However, contradictory research suggests, congruent with Mori’s uncanny valley theory, human acceptability of sounds depends on the realism of the context [17], therefore suggesting zoomorphic robots should vocalise animal sounds rather than human language.

Aesthetics. A robots appearance is another important issue. Of particular interest here is a debate on using familiar or unfamiliar forms. Previously, older adult care providers perceived ‘looking like a real-life pet’ as important, and suggested robots with familiar forms met requirements for older people more adequately than unfamiliar forms [11]. Conversely, familiar form contrasts the intentionally unfamiliar design of Paro [18], for the purpose of reducing expectations. However, familiar alternatives to Paro may actually be more acceptable to older adults [9], prompting further exploration into suitable aesthetic design. For example, it is possible variable responses to Paro [1], are a consequence of the design not being accepted by all [9].

Technology. Further technological additions exist for which there currently is no consensus on importance, for example, detachable/washable fur. This was previously identified by care providers as a requirement, although only by three participants, being the third least important feature for inclusion [11]. However, other studies have specifically highlighted infection control as significant for these devices [19], with detachable/washable fur a feasible solution. Another factor impacted by technology included, and often overlooked in literature, is economic cost of such platforms. Many robots can be expensive for settings such as care homes; for example Paro currently costs over £5000. Although Mervin et al. [20] demonstrated Paro can provide a cost-effective intervention for agitation in older people, the initial outlay is reported as too much by H&SC stakeholders in contact with us, while affordability is also a key concern of older adult relatives [21]. Alternative platforms vary in price (e.g. NeCoRo originally ~£1250, AIBO ~£2300, JfA cat ~£100), however the literature still lacks a stakeholder-driven understanding of appropriate costs, even though this factor is highly influential in real-world purchase and adoption decisions. It is also relevant for designers and manufactures when selecting included technology, which would impact affordability.

Interaction Type. Related to technology used is the interaction method of the device itself. Currently available devices vary in use of sensors and level of intelligence provided to the robot’s response. Moyle et al. [1], conducted research comparing Paro to an inert plush toy. Paro demonstrated no superiority over the plush toy for improving mood or agitation. The toy had no responsiveness, yet could arguably have been a more economical alternative to Paro. Similarly, research previously identified requirements for further enquiry on suitable level of interactivity [9], as older adults responded more positively to less sophisticated interaction of JfA pets (limited pre-programmed movements in response to touch and sound), than more technologically advanced interactivity of Paro (artificial intelligence, response adaption, touch, light, sound, posture, temperature sensors).

While some research has explored design previously, limitations include a lack of Paro as a comparison [11] and small sample sizes. Comparing a range of devices would allow more informed opinions, as participants would have direct experience of a range of aesthetic, behavioural, and technological features. Some previous research relied on passive materials (booklets/PowerPoints/TV) rather than live robot demonstrations [11,13], which limits assessment of robot capabilities. A further issue is use of devices not designed as companions [17]. From the literature, it seems clear there is no current agreement on optimum companion robot design for older people. This, therefore, is our core contribution, allowing insight into priority design features for future robots.

Methods

Setting and procedure

We held interaction stations at nine UK events: conferences on eHealth, dementia, aging and psychiatry, two dementia-specific health-professional meetings, a nursing workshop, a care awards event and a care home meeting. Attendees who approached our stand had the opportunity to interact with eight devices (Fig. 1), then complete a questionnaire. The University of Plymouth Faculty of Science and Engineering Ethics Committee granted ethical approval, participants provided written informed consent.

Fig. 1. Devices. From left, Paro, Miro, Pleo, JfA dog, JfA cat, Furby, Perfect Petz dog, Hedgehog.

Data collection

Questionnaires gathered demographic data (age, gender, occupation), and established i) priority design features, ii) preferred animal for target audience, iii) most appealing eyes, iv) most appropriate size, v) most appropriate volume and frequency of vocalisations, vi) reason for preferred animal, vii) reason for most appealing eyes and viii) realistic price. While priority feature ranking aimed to assess most and least important features for inclusion on devices for this target audience, the questions on preferred animal, eyes, size, vocalisation and prices aimed for greater understanding of design preferences in relation to currently available devices, with these features in particular selected due to discordance and discussion in previous literature. To establish i) priority features, each questionnaire was different and individually printed to include a specific combination of 10 features for participants to rank, picked from a total of 42 features related to aesthetics, behaviour, technological ability, feel and interactivity type (Table 1). The five categories were based on the discordance demonstrated around these aspects in previous literature. The 42 features were arrived at through combination of those previously reported by Heerink et al. [11], and inclusion of additional features highlighted during our previous study (to be reported elsewhere) on perceptions of care home residents, relatives and staff after interaction with the devices in Fig 2. A computer script was used to inform which 10 features appeared on each questionnaire, to produce a set of questionnaires where all features appeared with comparable frequency. To establish ii) preferred animal, participants selected from a row of pictures under the appropriate question. This was also the case for iii) – v). For vi) – viii), establishing reasons behind choices and reasonable price, free text boxes were used.

Table 1. Five design categories showing 42 features of interest included on questionnaires.

Category	Features of interest for each design category
Feel	Soft pettable fur; Huggable (right size to cuddle); Portable (ease to take with you); Solid/robust (can withstand rough handling); Realistic animal weight; Simulated warm feeling; Hard/plastic shell (eg. Pleo or Miro); Simulated breathing; Simulated heartbeat
Behaviour	Animal-appropriate responses/sounds (eg. Dog barking); Variety of behaviours and sounds; Active; Looks at user (animal provides eye contact/attention); Can talk to user (human speech); Vocalisations not too loud; Playful; Facial movements/expressions; Waggy tail; Animal appropriate behaviours
Aesthetics	Looks like a real life pet; Young or innocent looking; Nice/not scary; Cartoonish appearance; Flash/draws attention; Mythical animal; Cute eyes; Familiar animal (eg. Dog/cat); Unfamiliar animal; Cute; Customisable look/animal for each user
Technology	Mechanical parts are noiseless; Realistic movements (fluent/natural); Adaptable (shut functions on/off); Autonomous system; Easy to use; Fur is detachable (to be washed); Long battery life; Cleanable
Interaction Type	Interactive: Obeys some commands (eg. Sit/paw); Interactive: Looks at me or vocalises when I am near; Interactive: Looks at me or vocalises when I stroke or touch it; Interactive: Looks at me or vocalises when I talk to it

Data analysis

To explore i) priority design features, establishing an exact ranking of all items is computationally and prohibitively expensive, requiring evaluating all 42 factorial possible rankings against consistency with the data. To obtain an approximate ranking, we used a variant of the Condorcet method [22]: for each feature, we counted how often it is ranked higher than other features across all questionnaires. Note this ranking is approximate – while there is reasonable confidence high-ranked items would indeed be high-ranked and low-ranked items low-ranked in an exact ranking, it does not allow strong claims as to precise ranks. For data on ii) preferred animal, iii) most appealing eyes, iv) most appropriate size, v) vocalisations and viii) price, we report descriptive statistics. For vi) reason for preferred animal and vii) reason for most appealing eyes we provide most common free text comments. Although we collected participant age, gender and occupation, this was to contextualise results, and these factors were not used in analysis.

Results

Participants

In total, 113 questionnaires were completed. Participants were mainly H&SC professionals within gerontology, dementia, psychiatry, psychology and nursing (n=68), although other stakeholders participated (9 academic/researchers, 5 informal carers, 24 other, 7 missing). Participants included 87 females, 17 males and 9 cases of missing gender, average age being 48.1 (range=18-75, SD=14.2).

Priority design features

The most important features were considered to be interactivity (in response to talking to or touching the robot), being the right size to hug, having soft fur, a variety of behaviours/sounds, realistic movement and providing eye contact (Table 2). A hard/plastic shell, cartoonish appearance, and a mythical or unfamiliar design ranked lowest.

Table 2. Showing i) the features ranked in order of importance, based on the number of times they were scored higher than the features presented alongside them.

Ranking (Scores)	42 Features listed in order of importance
Highly rated 1-15 (190-130)	Interactive: Looks at me or vocalises when I talk to it; Huggable (right size to cuddle); Soft pettable fur; Variety of behaviours/sounds; Realistic movements (fluent/natural); Interactive: Looks at me or vocalises when I stroke or touch it; Looks at user (provides eye contact/attention); Easy to use; Looks like a real life pet; Simulated warm feeling; Nice/not scary; Animal appropriate sounds; Familiar animal; Facial movements/expressions; Cleanable
Middle ranking 16-29 (127-82)	Active; Autonomous system (works on its own); Interactive: Looks at me or vocalises when I am near; Long battery life; Animal appropriate behaviours; Cute; Cute eyes; Waggy tail; Portable (easy to take with you); Vocalisations not too loud; Playful; Adaptable (switch functions on/off); Solid/robust (can withstand rough handling); Young/innocent looking
Low rated 30-42 (41-23)	Interactive: Obeys some commands (eg. Sit/paw); Simulated breathing; Simulated heart beat; Fur detachable (to be washed); Realistic animal weight; Customisable look/animal for each user; Can talk to user (human speech); Mechanical parts are noiseless; Flashy/Draws attention; Unfamiliar animal; Mythical animal; Cartoonish appearance; Hard/plastic shell

The preferred currently available device was the JfA cat, followed by the JfA dog, then Paro (Fig 2). The least preferred options were Miro, the knitted Hedgehog and Furby. When asked reasons for preferences, frequent responses included being realistic, soft, cuddly lifelike, and familiar. Fig 2 shows the JfA cat was considered to have most appropriate vocalisations while Paro had the most appealing eyes. When asked what made the eyes appealing respondents used words like large, big, cute and eyelashes. Stakeholders thought Paro (~57cm X 35cm) was too large for older people and JfA cat (~39cm X 26cm) was most appropriately sized (Fig 2). (There were missing values for most questions: 15 did not respond to preferred animal, 27 to appropriate vocalisations, 23 to most appealing eyes, 36 to most appropriate size).

Fig. 2. Percentage of responders selecting each animal as ii) preferred, iii) most appealing eyes, iv) most appropriate size, v) most appropriate vocalization volume/frequency

Price

For viii) reasonable price, an example range was provided from £10-£5000 for devices on display. For participants who responded with a range (e.g. £100-£150), we took the highest figure as the maximum they consider appropriate. The average price participants felt was appropriate was £226.30 (SD=245.80, range=£25-£1000).

Discussion and Conclusion

Although participants in this study were generally stakeholders in the H&SC professional category, the features included in the questionnaires were derived from prior work with end-users, care staff and family members, and combined with those reported by Heerink et al. [11]. Heerink et al. [11] noted their acquired list of requirements provided the basis for further research, suggesting attributions of weight to measure importance of each feature among stakeholders. We have furthered this initial work. Thus, the results of this study provide overall insights from collective opinions of key stakeholders in the real-world adoption of companion robots, having implications for future robot development, particularly considering importance of user-centred design specifically for robot pets [9]. Supporting Heerink et al. [11], our stakeholders confirmed, with a relatively large sample, the importance of soft fur for companion robot shells, although of course care must be taken in cleaning [19]. The findings also strongly support familiar-realistic animal embodiment. Previous work with a small sample similarly demonstrated, contrary to the intentionally unfamiliar design of Paro [18], older people preferred familiar animal designs [9]. Here, our sample of stakeholders scored ‘looks like a real life pet’ and ‘familiar animal’ within the top 15 most important features, and top three specific to aesthetics. In contrast, ‘unfamiliar animal,’ ‘mythical’ and ‘cartoonish’ were all features receiving low priority. Participants also selected devices with familiar embodiment as preferable with older adults in mind (JfA cat/dog), rather than unfamiliar options, and commonly reported realistic, life-like and familiar in free-text reasons for device preference. The continued support for familiar animal embodiment has implications for future robot design, and also selection of devices for real-world implementation, perhaps explaining some variation in response towards Paro [1]. Research into these alternate devices may even demonstrate more consistent wellbeing outcomes than Paro [1], should a familiar design be more acceptable to intended users. This study, and prior work [9] suggest requirement for more research with alternate robots rather than just Paro [3]. As companion robots can support wellbeing [4,5], developing future devices with optimum aesthetic and behavioural design to promote acceptability, real-world implementation and use is important, as is ensuring affordability.

Congruent with family members previously suggesting Paro was too expensive [21] our stakeholders suggested an average suitable price for a companion robot far below the £5000 for Paro, at ~£226. This result has implications for developers, allowing insight into the outlay real-world stakeholders would consider appropriate, to guide future device developments to ensure affordability. It is therefore likely technological sophistication would be more limited. This study has allowed for prioritisation of features to assist in keeping devices affordable. The most important factor as reported by our stakeholders was a variety of behaviours and sounds. It appeared this influenced preference for the JfA cat, who has a larger range of movements and behaviours than other devices. Eye contact also scored well during feature ranking, being the second most important behaviour, and was noted in free-text reasons for preferred eye design. Intentional eye contact could thus be a justifiable expense on future devices. Paro’s eyes were seen as most appealing. Reasons included being large, having eyelashes, blinking and making eye contact. These results could form the basis for future eye design.

A further novel contribution of this paper is prioritisation of interaction type. Previous work [9], demonstrated the technically sophisticated interactivity of Paro was undervalued by older adults. Such sophistication may create unnecessary expense and simpler interactivity could allow affordability. Our stakeholders felt it most important devices respond to user’s vocalisations, followed by response to touch. Responding to touch and sound are the capabilities of JfA devices, potentially demonstrating a sufficient level of technology for this user-group. Limited value in robot interaction when a user looks at it somewhat contrasts desire for eye contact, which could therefore be achieved by robot gaze direction based on noise sources, rather than gaze recognition.

Alternative interaction methods and functions could potentially be neglected in favour of affordability. Reducing technological sophistication appears unlikely to negatively impact acceptability, providing optimum soft-furry feel is achieved, aesthetic design is familiar and realistic and there is a variety of behaviours, including perceived eye contact. The preference for the JfA cat in this study and prior work [9] indeed supports acceptability of devices less sophisticated than Paro. In contrast to previous work however [9], where older adults valued inclusion of human speech from companion robots, human speech was not perceived as important among stakeholders in this study. This may reflect a difference between stakeholder categories of end-user and professional. The speech discrepancy may therefore demonstrate older adults perceiving an unmet need currently undervalued by professionals; for more verbal interaction.

Regarding size, stakeholders previously reported to us concerns on Paro’s size, with carers suggesting it was too large for older resident’s laps. These results suggest the most appropriate size is best reflected in the JfA cat, which is considerably smaller and lighter than Paro. The JfA cat appears similarly sized to live cats, and perhaps further to practicality of fitting on older adults’ laps comfortably, preference may again reflect desired realistic embodiment, most accurately depicting the real animal. Questionnaires also explored life-simulation features, including breathing, warmth, heartbeat, as mentioned by older adults previously [9]. Such physiological expressions may increase perceptions of devices being alive, these results suggest simulated warmth is stakeholder’s priority in this area, as the third most important ‘feel’ feature, and tenth overall, winning far more comparisons than heartbeat or breathing. Simulated warmth is lacking on any available companion robot and is thus interesting for future designs.

These results have important implications, considering aesthetic and behavioural robot design can impact acceptability and use [7], and also considering the profound health and wellbeing potentials such devices possess [4]. This paper presents a comprehensive exploration of design across a relatively large sample of stakeholders, with insight for feature prioritisation allowing for affordable future robot development. It is interesting stakeholder design preferences differ so greatly from the most well researched companion robot, Paro [3], and certainly suggests potential for improvement.

Limitations of this work include reliance on immediate perceptions of stakeholders, without longer, real-world observations of end users with devices. Thus, perceptions may differ between initial thoughts and features encouraging longer-term engagement.

Conclusions. Stakeholders in the care of older people prefer familiar, realistic embodiment for a companion robot. Paro, the most well-researched such device, is rated less highly, being unfamiliar, and too big, suggesting the need for diversification of device choice in future companion robot research. Our study provides insights allowing designers to prioritise the most necessary features and capabilities, whilst adhering to the reported affordable price point of ~£226. Optimum design could include; interaction in response to vocalisations and touch, huggable size, soft fur, variety of behaviours/sounds, realistic movements, providing eye contact with large, cute eyes, being realistic and familiar, easy to use and possessing a simulated warm feeling. Devices developed to stakeholder cost and design requirements could be more widely implemented in real-world settings, perhaps with more consistent wellbeing outcomes.

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