A Study of Product Interface Design from Lifestyle Angle for the Geriatric A Case of Digital TV Interactive Function Menu Design Chih-Fu Wu 1, Chun-Ming Lien 1,2*, and Fang-Ting Chao 3 1, 3 Department of Industrial Design University of Tatung No.40, Sec. 3, Jhongshan N. Rd. Jhongshan District Taipei City, 10452, Taiwan 2* Department of Industrial Design University of Huafan No. 1, Huafan Rd. Shihding Township Taipei County, 22301, Taiwan cmlien@hfu.edu.tw Abstract: Taiwan has long turned into an aging society according to the qualification provided by United Nations. In Taiwan, the interface design for the geriatric is becoming crucially important, especially on television because they rely on television very much, meaning they spend most of their time on TV. In the quite near future, Digital Televisions (DTV) will be prevailing and provide various services. For the geriatrics, when choosing the ideal DTV, the interface design of DTV will influence decision of purchase. The study has two steps. First, use questionnaire to collect lifestyles of the geriatric and needs for functions by DTV. And divide the geriatric lifestyles into groups by cluster analysis. Also, name each lifestyle by its feature and find out different needs. Second, design interface on the basis of questionnaire result. By using ASP technique (Active Server Page 3.0), time consuming on each web page and the inaccuracy rate from Subjects can be measured. The statistical analysis result can prove the appropriateness of interfaces for different age groups. The study shows the geriatric can be classified two groups- Family Lover-Style Group and Energized-Style Group. These two groups have different needs on the sequence of DTV interactive functions. All groups have high demand on random film option function and instant weather forecast function but low on instant on-line interactive service. Different lifestyles request different service functions. According to the study, the geriatric has preference for customized interactive function design. Besides, for the adult group, the study finds out new interface designs pass Universal Design principle test and meet the needs for most of the users. Keywords: Lifestyle, Geriatric, Interface Design, Digital TV 1. INTRODUCTION When discussing consumers needs and preference, population statistics variables such as sex, age, occupation are usually used to categorize customers. However, classify consumers with different backgrounds and personalities in the same category, the result of the study can be different and caused blind spots. Therefore, designers can not analyze consumers needs and preference only based on population statistics variables, lifestyle variable should be added when study products and their designs. According to foreign studies, television plays an import role in geriatric life. In Taiwan, the study on geriatric leisure life indicates that watching TV is a top 10 leisure activity for geriatric whether in nursing home or at home (Chung, S. K. & Hwang, K. Y., 1987). In most of TV interface study, the focus is on interface design s specifications and regulations and is not much on its function due to the geriatric with different lifestyles. Comparing with traditional TV operation, DTV is more complicated in operating. DTV will be prevailing. Therefore, for designers, when designing interfaces for DTV, the lifestyle variance should also be considered because it helps to design the useful functions, which can enhance independence of the geriatric, the working efficiency and safety. Moreover, the practical functions can build up the good interaction between the geriatric and products.
2. ANALYSIS ON INTERRELATION BETWEEN LIFESTYLE AND DTV Due to differences in living environment and background, diverse lifestyles of groups have different cognition and needs. Characteristic and need of the group can be discovered through differences. Therefore, in this step, questionnaire and statistical analysis will be applied to find out the interrelation between lifestyle and DTV because it is the first step to understand the needs and differences in groups. Moreover, it can be a pilot knowledge for interface option design. 2.1 Questionnaire Design First part of the questionnaire is to gather demographic data on the participants including sex, age, living status, education level, income source, living district and electronic appliance operation. The second part of the questionnaire is to survey lifestyle. In lifestyle part, AIOs Lifestyle Measure Chart by Plummer (1974) is the basis to construct the questions. Questions are also referred to studies of Chen(1995) which are related to geriatric lifestyle, the interrelations between isolation degree and watching behaviors. Moreover, questions are a integration from the study of Chang(1994), the study of Ling(1999) and previous experimental results. The questions are more related to activities, opinions, and hobbies of the geriatric. The questionnaire measured by Listert Scale is divided into 10 parts and 25 questions of each. The third part of the questionnaire is DTV interactive function and service. Questions including 27 functions and services are from the report Taiwan Digital Consuming Need for Life Survey- on Home Entertainment (MIC, 2006) by Institute for Information Industry. 2. 2 Determine Sample and Investigation In order to compare different lifestyles of the geriatric and the differences between the geriatric and the adult, the 250 participants are to be investigated. Age of the control group is from 18 year-old to 65 year-old, and the age range is divided by every 10 years old. Select 30 samples from each age range and 150 participants are in total. In experimental group, 100 participants above 65 years old are investigated. Questionnaire is distributed in Taipei area and the investigation method is random selection. In the geriatric investigation part, due to their physical limitations and education level differences, the oral question-response method is applied on the geriatric by well-trained investigators for the accuracy. Participants who are below 65 years old do the questionnaires themselves. 2. 3 Cluster Analysis on Lifestyle The result, the average of every variable from each group, is being persistently tested and is analyzed by Ward s Cluster Analysis. The geriatric participants are classified into two groups. For the accuracy of dividing groups, these 2 groups are tested by category research principle and distinguish analysis verification. The value of the test- numbers of group is 1.6 to 3.3, Willk s Lambda value is 0.140, Chi-square value is 167.924 and P value<0.05 shows the classification of groups is accurate. 2. 4 Feature of Each Lifestyle and Denomination After cluster analysis, apply crosstabs on the mean of the result from questionnaire and lifestyles of two groups. Through Ch-Square test, the study indicates the distinguished difference (P value < 0.05). By lifestyle features, these two groups can be named Family Lover-style Group and Energized-Style Group. Though crosstabs, the study indicates the education level (P=0.00<0.05), income source (P=0.00<0.05), and living district (P=0.041<0.05) can influence the geriatric lifestyle. 2. 5 Digital TV Function Needs for Each Lifestyle Group Based on statistics, the geriatric lifestyles can be classified into two groups. In the study, the adult group is regarded as Fashion-Style Group. Through One-way ANOVA of Variance to test lifestyle and Digital TV function, it can help us to know each variance s influence on DTV function. By each lifestyle s F values and P value, differences of each variance can be
distinguished. Moreover, with ANOVA and Scheffe s Method, it can tell whether there s a distinguished difference within groups and can tell the DTV function needs for each lifestyle. Family Lover Style: Besides having preference on random film option and instant weather forecast function, this group has high demand on pause function, community information inquiry, transportation timetable, video telephone function because they care about their families very much though they may not be around. In addition, they care about the community. Energized Style: Besides having preference on random film option and instant weather forecast function, this group has high demand on fast forward program function, random music option, breaking-new option, and digital learning program function because they care about efficiency and voluntary learning and are happy to seek for their hobbies and eager to know the latest information. Fashion Style: Besides having preference on random film option and instant weather forecast function, this group has high demand on random music option, video telephone, on-line TV program and instant transportation inquiry function because they are younger and have higher exposure to computer and information. Therefore, this group has higher demand on internet and the information relevant to convenient life. Reviewing Family Lover-Style Group and Energized-Style Group s percentage of need, it is obvious that Energized-Style Group has higher demand on e-mail, on-line shopping, on-line investment management, on-line banking service and on-line games function than Family Lover-Style Group. Family Lover-Style Group prefers program pause function while Energized-Style Group prefers program fast forward function. These phenomena are affected by each group s characteristic. 2. 6 Summary The geriatric is very looking forward to getting information they want when they turn on digital television. However, the searching action makes it unfriendly for them. The reason for this is the geriatric seldom use computers, not to expect them to play on-line games and get e-mails on line, so it would be practical if the digital television can have speech sounds. Digital television will be a trend in future because it provides additional services than just play programs. From tabulated statistics of lifestyle and DTV function, the study finds that random film option function and instant weather forecast function are requested for each group while instant online services including investment management and banking service, and on-line games are less demanded. 3. EXPERIMENT DESIGN In Taiwan, only Chunghwa Telecom provides digital television service. The study apply Big Television of MOD (Multimedia on Demand) function provided by Chunghwa Telecom, as a basis, into an experiment to design operation menu for Family Lover-Style Group and Energized-Style Group. In this experiment, the relationship with Fashion-Style Group will be discussed as well. 3. 1 Purpose of the Experiment The Interaction of the geriatric users with product interfaces can be examined in the experiment. Purposes are described as followed: 1. Use five different tasks of operation interface to evaluate the geriatric user s application performance; 2. Understand the geriatric mental response and cognition when operating various interfaces; 3. Compare the geriatric user s performance on different operation interfaces; 4. Result of variances caused from the geriatric difference; 5. Evaluate appropriateness of each interface by efficiency, inaccuracy rate, and subjective assessment. 3. 2 Experiment Variables Due to different lifestyles, the study utilizes MOD as a model to make imitated web pages. One different thing of these three interfaces is the sequence of the function. Therefore, in this study, the sequence of the function is used to be independent variable. The sequence of the function is MOD, Interface 1 (Family Lover-Style), and Interface 2 (Energized-Style). According to the efficiency of user s application,
the dependent variables are searching time, browse page, and Subject s subjective assessment. 3. 3 Experiment Method In order to know the geriatric users operating responses due to different interfaces and what they think of the interfaces, the study adopts computing logging method to objectively record all users actions and analyze their operating procedures. Questions arisen when operating are also being recorded and be brought into oral interviews with the geriatric after experiment. The testing web pages are made from Macromedia Studio MX software and relevant mapping software (). Use ASP technology inside the two Tablet PCs to make the recording operation system, Active Server Page 3.0, and apply the system to track consuming time on each web page and searching process. The experimental operation method is to use cursor remote control to execute the five tasks. MOD by ChungHwa Telecom is the basis of the experimental web pages. There are 15 function option bars on the left side of the page. Six options can be shown a time. Because most of services provided by MOD are random film selection, functions in the questionnaire would be integrated in the study. The sequence of the function category will be followed by Institute of Information Industry s Digital TV Function Classification. In addition, with integration of MOD function and questionnaire classification, the experiment designs the appropriate sequence of interface for the geriatric Family Lover-Style Group and Energized-Style Group. Big Television s function option adopts MOD as a model. The option of Interface 1 is designed for Family Lover-Style Group while Interface 2 is for Energized-Style Group (shown in Figure 1). The study takes these three interfaces into experiment. Big Television s function option adopts MOD as a model Interface 1 is designed for Family Lover-Style Group Figure 1. The three interfaces for experiments Interface 2 is for Energized-Style Group 3.5 Experiment Limitation The purpose of this experiment is to know whether the function of model design reaches the need when operating for users. Digital television provides various services but in this study only the customized interactive function will be discussed. Variances such as data uploading speed and system operation efficiency are excluded. 3.5 Subject The experiment was taken place in the geriatric service center in Chung Shan district. Before the experiment, the Subjects above 65 years old are asked to do the questionnaire in order to put them into categories. 10 samples were collected, 5 samples for Family Lover Style and 5 for Energized Style. Besides, 10 samples from 18 years old to 65 years old are Fashion-Style Group.
3. 6 Experiment Procedures The first step of the experiment is to ask 10 more than sixty-five years old Subjects to operate MOD interface. Five of them identified as Family Lover-Style participants operate the Interface 1 and the other five identified as Energized-Style participants operate Interface 2. The experiment tasks referred to previous questionnaire are composed from five tasks due to the designs for the geriatric needs. Each Subject will follow task instruction to search answers from three options of each task. The task will be randomly selected. After the task, each Subject needs to do the subjective assessment questionnaire which has eight questions and seven of them adopt Likert Scale. Likert Scale can tell the Subject s satisfaction degree and difficulty of tasks. One open question let the geriatric express their opinions freely. The experiment flow is as figure 3. 4. 1 Searching Time and Numbers of Browse Page 4. RESULT OF EXPERIMENT Active Server Page (ASP) technology records all operation including searching time of each web page and searching path in computer during the experiment. The operation time can be calculated by consuming time of each task. As figure 4 shown: The consuming time of each five task by the geriatric is shown in figure 1. From figure 1, it can tell the speed of operating interface of each Subject. Some are quick in operation and some are slow but the number of pages they browse is similar. However, from the result, it is obvious that these two groups of geriatric spend less time on operating Interface 1 and 2 than operating MOD. From the questionnaire analysis and DTV function need investigation completed by 150 Subjects who are below 65 years, the result tells that the sequence of need for interface function is the same as the Energized-Style Group because functions provided by MOD do not have many varieties, mainly are random music selection and random film selection. Ask 10 Subjects, above 65 years old from Fashion-Style Group, to perform five tasks of MOD interface and interface 2. The result (shown in table 1) indicates that every Subject has different speed in operating but they all spend less time in each task than the geriatric Subject. Group geriatric Group Group Adult Group Table1 The Searching Time and Numbers of Browse Page by different groups Subject Interface 1 Interface MOD Mean Mean Total Mean Mean Total Mean Mean Total Time df. Page df. Time df. Time Page Time Time Page Time geriatric 1 150.2 3.8 751 199.6 4 998 49.4 0.2 247 geriatric 2 165 3.8 825 185.2 3.8 926 20.2 0 101 geriatric 3 120.8 3.8 604 128.4 3.8 642 7.6 0 38 geriatric 4 99.2 3.8 496 105.6 3.8 528 6.4 0 32 geriatric 5 113.2 3.8 566 170.2 3.8 851 57 0 285 Interface 2 Interface MOD geriatric 6 140 3.8 700 165 3.8 825 25 0 125 geriatric 7 187.4 3.8 937 194.6 3.8 973 7.2 0 36 geriatric 8 181.4 3.8 907 194.8 3.8 974 13.4 0 67 geriatric 9 217 3.8 1085 223 3.8 1115 6 0 30 geriatric 224.2 3.8 1121 238.4 3.8 1192 14.2 0 71 10 Subject Interface 2 Interface MOD Mean Mean Mean Mean Total Mean Mean Total Time df. Page df. Time Page Time Time Page Time Adult 1 27.8 3.8 139 40.4 4 202 12.6 0.2 63 Adult 2 27 3.8 135 37.6 3.8 188 10.6 0 53 Adult 3 31.8 3.8 159 31 3.8 155-0.8 0-4 Adult 4 30.6 3.8 153 44.8 3.8 224 14.2 0 71 Adult 5 29.2 3.8 146 47.6 3.8 238 18.4 0 92 Adult 6 32.8 3.8 164 41 3.8 205 8.2 0 41 Adult 7 31.4 3.8 157 34 3.8 170 2.6 0 13 Adult 8 27 3.8 185 47 3.8 235 10 0 50 Adult 9 31.2 3.8 156 30.6 3.8 153-0.6 0-3 Total Time df. Adult 10 32.8 3.8 164 43.4 3.8 217 10.6 0 53
In operation efficiency, the average operating time by 5 geriatric Family Lover-Style Subjects is 157.8 seconds and 129.68 seconds for MOD and Interface 1 separately. Their P value is 0.0285<0.05; the average operating time by 5 geriatric Energized-Style Subjects is 203.16 seconds and 190 seconds for MOD and Interface 2 separately. Their P value is 0.009<0.05. While the average time by Adult Group (referred as Fashion-Style Group) is 39.74 seconds and 31.16 seconds for MOD and Interface 2 separately. Their P value is 0.001<0.05. The result discovers the interface design for each group based on their lifestyles is easier to be operated than MOD. For the Adult Group, the efficiency for operating Interface 2 is higher than operating MOD. Therefore, it indicates that the Interface 2 is appropriate for the Adult Group as well and it also complies with Universal Design spirit. Table 2. Operating time comparison to the interface Group Interface Mean N Std. Deviation Std. Error Mean Family Lover-Style MOD 157.800 5 39.500 17.665 Family Lover-Style 129.680 5 27.148 12.141 Energized-Style MOD 203.160 5 28.438 12.718 Energized-Style 190.00 5 33.464 14.966 Fashion-Style MOD 39.740 10 6.262 1.980 Fashion-Style 31.160 10 2.842 0.899 Table 3. Difference examine of operating time comparison to the interface Paired Differences Sig. (one-tailed) Mean Std. Std. Error 95% Confidence Interval Group Interface Deviation Mean of the Difference t df Lower Upper Family Lover-Style MOD - Family Lover-Style 28.120 23.677 10.589-1.279 57.519 2.656 4 0.0285* Energized-Style MOD - Energized-Style 13.160 7.552 3.377 3.783 22.537 3.897 4 0.009* Fashion-Style MOD - Fashion-Style 8.580 6.347 2.007 4.040 13.120 4.275 9 0.001* α=0.05 4. 2 Task Inaccuracy Rate The complement rate of each five task for two interfaces by 10 geriatric Subjects is 100 percent. Though the operating time is very long but the inaccuracy rate is almost zero. However, only one geriatric Subject made mistake on answering option code. The inaccuracy rate of the Adult Group is zero and they spend less time on operating than the geriatric users. 4. 3 Subjective Assessment The assessment will be based on operating task difficulty, the satisfaction toward the interface, and analysis of Subject evaluated attitude. The mean of each question can be index for Subject s attitude. From statistic analysis of the geriatric and the adult subjective assessment (shown in table 4), the result shows the geriatric groups and the adult groups give the above average points on 5 tasks difficulty and the satisfaction for two interfaces. And from one-way analysis of variance, there s only a significant difference in task 2 (p=0.002<0.05). However, the result can not provide the significant difference between other four tasks difficulty and satisfaction by 20 Subjects of three lifestyles. Therefore, only by observation record during the experiment can the feelings and needs of Subject be discovered. Table 4 Descriptive statistical table of subjective assessment questions N Mean 95% Confidence Interval of Std. Std. Error Min. Max. the Difference Deviation Mean Value Value Lower Upper Task 1 Family Lover Style 5 3.80 1.10.49 2.44 5.16 2 5 Energized Style 5 3.00 1.22.55 1.48 4.52 1 4 Fashion Style 10 3.30.95.30 2.62 3.98 2 5 Total 20 3.35 1.04.23 2.86 3.84 1 5 Task 2 Family Lover Style 5 3.80 1.10.49 2.44 5.16 2 5 Energized Style 5 3.20 1.10.49 1.84 4.56 2 4 Fashion Style 10 2.00.47.15 1.66 2.34 1 3 Total 20 2.75 1.12.25 2.23 3.27 1 5
Task 3 Family Lover Style 5 3.80 1.10.49 2.44 5.16 2 5 Energized Style 5 3.20.84.37 2.16 4.24 2 4 Fashion Style 10 3.70 1.16.37 2.87 4.53 1 5 Total 20 3.60 1.05.23 3.11 4.09 1 5 Task 4 Family Lover Style 5 3.80 1.11.49 2.44 5.16 2 5 Energized Style 5 3.40.55.37 2.72 4.08 3 4 Fashion Style 10 4.20.79.37 3.64 4.76 3 5 Total 20 3.90.85.23 3.50 4.30 2 5 Task 5 Family Lover Style 5 3.80 1.10.49 2.44 5.16 2 5 Energized Style 5 4.00 1.00.45 2.76 5.24 3 5 Fashion Style 10 4.20.92.29 3.54 4.86 3 5 Total 20 4.05.94.21 3.61 4.49 2 5 Interface 1 Family Lover Style 5 4.20.45.20 3.64 4.76 4 5 Energized Style 5 3.80.84.37 2.76 4.84 3 5 Fashion Style 10 4.20 1.03.33 3.46 4.94 2 5 Total 20 4.10.85.19 3.70 4.50 2 5 Interface 2 Family Lover Style 5 4.40.55.24 3.72 5.08 4 5 Energized Style 5 3.80.84.37 2.76 4.84 3 5 Fashion Style 10 4.10.74.23 3.57 4.63 3 5 Total 20 4.10.72.16 3.76 4.44 3 5 4. 4 Experiment Result According to the experiment result, the education level of the geriatric is high. Among them, nine geriatric Subjects financial sources are from retirement pension. It is assumed that the geriatric Subjects are independent and have higher learning motivation. Both the geriatric group and the adult group have more efficiency in operating Interface 1 and 2 which are designed specific for the geriatric than in operating MOD. From time consumption of interfaces, the study finds that the geriatric has high demand on customized interactive function interface, and they need more time in adapting themselves in using new interfaces. Therefore, personalized interfaces may reach their needs. 5. 1 Conclusion 5. Conclusions and Suggestions Along with tremendous information service provided by DTV, the DTV functions become more complicated. When it comes to design interfaces for DTV, too many aspects need to be considered, not just design interfaces from intuition. Not only demographic statistics but also lifestyles need to be fused into designing. When facing questions caused from the geriatric interface application, besides human-related theories, the actual needs by face-to-face interviews of the geriatric should be accounted into the study. Therefore, in the study, through questionnaire investigation and experiment of interface application, results can be reference for future academic studies and designing fields are described as below: 1. Use tabulated statistics to discuss the relationship between each group s demographic variances and lifestyles. The study discovers three factors- education level, income source, and living distric influence the geriatric lifestyle. 2. Different lifestyles have different needs for interfaces. Besides having high demand on random film option and instant weather forecast function, Family Lover-Style Group has preference on program pause function, community information inquiry, transportation timetable, and video telephone function. As for Energized-Style Group, besides having high demand on random film option and instant weather forecast function, this group prefers fast forward program function, random music option, breaking-new option, and digital learning program function as well. 3. Comparing with MOD interface, the interface designed for the specific lifestyle is more appropriate for the group. From analysis of operation record tracked by computer and the mean of the consuming time, the study discovers that Family Lover-Style Group is more efficient in operating Interface 1 than operating MOD interface. Energized-Style Group and Fashion-Style Group are more efficient in operating Interface 2 than in operating MOD interface. 4. When the Adult Groups apply two interfaces designed specifically for the geriatric, the operating efficiency is better
than applying MOD. The result is in accordance with Universal Design principle. 5. According to the time consuming, the geriatric has higher demand on customized interactive function interface. When the Adult Groups execute the two interfaces, the average timing difference is not huge while the geriatric groups average timing difference is huge. 6. The levels of interface functions should not be too complicated. Due to the geriatric literacy, education levels, habits and living experiences, they might have difficulties in operating new product. Usually, they give it a try on first level, but when it comes to the third level, they become anxious. 7. When users have needs for computer and television, they have higher learning motivations. The product interface for the geriatric is highly related to the needs from users, especially when users have purposes. The users will be more interested in operating interfaces. And when having hard time operating the interface, the users would try hard to overcome the difficulties. 5. 2 Recommendations for future research Digital television has not been prevailing. Through interviews and questionnaires, the study knows the needs for DTV functions of different geriatric groups, since they do not have the real application on digital television. The study adopts investigation and experiment observation method. Due to limitation on time, facility and manpower, only the most prevailing interface model becomes the sample of the experiment. Whether interface model, experiment method and the special condition of the geriatric can be considered in designing, this needs to be further studied. In the future, besides, the actual application experience should be added into the study, the principle of interface design for the geriatric and the Universal Design principle should also be considered when making the imitative interfaces and examine the interfaces by experiment. In this way, the designers can design more appropriate DTV interfaces for the geriatric. ACKNOWLEDGMENT This study was assisted by the volunteers for geriatric service center of Zhong-Shan and Zhi-Shan (http://www.cthyh.org.tw/longcare/zs/index.htm) in Taiwan. This assistance is gratefully acknowledged. REFERENCES 1. Ling, C. C., 1999, Research on the Design Consideration of Scooter for the Old Based on Life Style Study, DA YEH University Graduated School of Industrial Design. Thesis for Master of Science. 2. Chang, L. S., 1994, Study of elderly peoples life-style and books consumption behavior in Taiwan, Institute of Communication Studies, National Chiao Tung University, Thesis for Master of Science. 3. Chen, Y. H., 1995, Study of Relationship of Old People's Life-Style, Estrangement Level with Watch Digital TV, Chinese Culture University College of Journalism Communication, Thesis for Master. 4. Chung, S. K. & Hwang, K. Y., 1987, The Old Man's Life-Style to Influence of Life Satisfaction, Report of Case studies by National Science Council,NSC76-0301-H004-08-A 5. Institute for Information Industry MIC, 2006, Digit life consumption demand survey report of Taiwan-Family's amusements, The analyzing of Digit TV to provide extra serve and prefer. 6. Plummer Jospeh T, 1974, The Concept and Application of Lifestyle Segmentation, Journal of Marketing,Vol.38, jan, pp33 37.