In order to address the accessibility of the Holobalance system
for older adults in different locations, two focus groups were
held in Freiburg (Germany) and Athens (Greece). For the purpose
of these focus groups, all prototypes and questionnaires were
prepared in both German and Greek languages. The participants of both
focus groups wore Docooler AR HMD and used balance Physiotherapy
Hologram (i.e., virtual coach) and Cognitive Training and Exercise Games
prototypes which were running on a Pixel 3 XL smartphone.
The Auditory Training Tool and Activity Planning App did not need the
headset. Therefore, they were used on the smartphone only. The participants
then evaluated these prototypes using several
Prototype Evaluation by Older Adults
(Tap the charts to see additional information)
71.4 mean age
DO YOU SUFFER FROM A BALANCE DISORDER?
Half of the participants had balance disorder.
HOW MANY FALLS HAVE YOU EXPERIENCED IN THE LAST 6 MONTHS?
They reported an average of 0.56 (SD=.82) falls and 0.85 (SD=1.32) near falls during the past 6 months.
HOW OFTEN DO YOU DO EXERCISE?
Our participants were also physically active as more than 70% of them reported daily (about 38%) or weekly (about 33%) performance of exercises. The rest (25%) stated that they never do exercises.
HOW MUCH FREE SPACE DO YOU HAVE AVAILABLE FOR DOING EXERCISES AT HOME? (square feet)
About 70% of the participants indicated that they have 3m² or more free space at home. 13% of them had 2 m² and the rest (17%) had 1 m² available space at home.
HOW CONFIDENT ARE YOU WITH TECHNOLOGY?
About 2/3 of these seniors had broadband internet at home and used computer (including smart phones, iPad, tablet, etc.) on a daily (58.33%) or weekly (4.16%) basis. On a scale of 1 (very bad) to 5 (very good) they rated their confidence in technology in average 2.33 (SD=1.34, Mdn=2.5).
HAVE YOU EVER USED A VR/AR HEAD-MOUNTED DISPLAY?
The majority of the participants (about 92%) did not have prior experience with AR or VR.
The System Usability Scale (SUS)  is a standardized questionnaire to assess the usability of a given product or service. The mean SUS score was calculated as 57.
SUS PER AGE GROUP
We ran Pearson correlation which suggested a significant negative correlation between the subjects' age and their SUS score. In other words, as the age of the participants increased, their evaluation of the usability of the system decreased.
NASA-TASK LOAD INDEX (NASA_TLX)
The results of the NASA-Task Load Index (NASA_TLX)  indicates that despite wearing a HMD, the system was not rated as physically demanding. The effort and frustration levels were also rated low. Although the mental and temporal demand was rated higher than other factors, they are still around the average score. Therefore, the overall workload during the testing was low to medium.
USER EXPERIENCE QUESTIONNAIRE (UEQ)
The results of the User Experience Questionnaire (UEQ)  can be seen in the figure above (values above 0.8, below -0.8, or between these two values represent respectively a positive (green background), negative (red background), or neutral (yellow background) evaluations). As it can be seen, all scales have a mean value above 0.8 which represent a positive evaluation. The system was mostly perceived as novel, stimulating, and attractive.
PERCEPTION OF THE VIRTUAL COACH
The Godspeed questionnaire  was employed to evaluate the representation of the virtual coach. Different aspects of the virtual coach are rated quite high. Therefore, the participants have perceived the virtual coach like a human (Anthropomorphism) who is alive (Animacy) and calm (Perceived Safety), has intelligence (Perceived Intelligence), and has left a positive impression on them (Likeability). In addition, the mean Social Presence  score (on a scale of -3 to +3) was 0.26 (SD=1.19). Since it is positive, it suggests that the participants perceived the virtual coach socially present in the physical room.
The questionnaire was composed of a demographic questionnaire, the System Usability Scale (SUS), User Experience Questionnaire (UEQ), NASA Task Load Index (NASA_TLX), and the perception of the virtual coach (Godspeed and Social Presence questionnaires).