Relationship between the Notebook Input Devices and Working Tasks

Transcription

1 Relationship between the Notebook Input Devices Working Tasks < digital picture> Wu Chih-Fu < IF AVAILABLE> Industrial Design/ Tatung University / No.40, Sec. 3, Zhongshan N. Rd./ Taipei / Taiwan wcf@ttu.edu.tw <digital picture> Lai Chih-Chun < IF AVAILABLE> Industrial Design/ Tatung University / No.40, Sec. 3, Zhongshan N. Rd./ Taipei / Taiwan lai@ttu.edu.tw Liu Yen-Kou Industrial Design/ Tatung University / No.40, Sec. 3, Zhongshan N. Rd./ Taipei / Taiwan cucucucu0@yahoo.com.tw Fu Mei-Chi Design General Division R&D Center TFT Buniness Unit /ChungWa Picture Tubes, Ltd. / No.1, Huaying Rd., Sanho Tsun, Lungtan Shiang / Taoyuan / Taiwan Huang Ming-Wei Design General Division R&D Center TFT Buniness Unit /ChungWa Picture Tubes, Ltd. / No.1, Huaying Rd., Sanho Tsun, Lungtan Shiang / Taoyuan / Taiwan ABSTRACT This research studies the correlation of using experience, genders tasks with built-in input s of notebook PCs. The experiment reveals that there are significant differences of built-in input s, using experience, genders cursors moving sensitivity on either/ both operating time error rate of specific tasks respectively. The result of subjective assessment shows that the touchpad with left right button sting upright in the lower left of keyboard gets higher the trackpoint with left right button below the center of keyboard get lower assessment. The cursors moving sensitivity with value 12 gets higher assessment. Keywords Notebook PC, input, touchpad, trackpoint, task INTRODUCTION At this moment, there have been many studies on different types of input of notebook PCs desktop PC, there are some studies on comparing among themselves. Elisabeth (1997) has compared the muscle loading of using mouse trackpoint. The result shows that the trackpoint can reduce the loading of the shoulder, but it increases the loading of forearm. The study from Akamatsu (2002) has

2 mentioned the comparison of applying force between touchpad mouse. By using the mouse, when the cursor approaches the target, the force applied by the h gradually decrease. The touchpad gets the opposite result. Regarding the control stick touchpad, Kelaher (2001) has compared the touchpad on different locations of the notebook PCs. There is certain discomfort accrued to h, neck shoulder. He has proposed the locations of the touchpad, the external touchpad is better to use. The result agrees with the study from Carolyn (2002) that is the external touchpad can enhance the comfortableness of providing tasks. Accot (1999) has adopted Fitts' Law to design a route task. The result shows that the time taken for touchpad to complete the circular straight route is longer than that for trackpoint. Liu Yu Wen (2004) has mentioned that using notebook PCs at the height of 80cm is most comfortable the task will be completed faster with trackpoint. In the study from Christine (2005), the touchpad has been compared with trackpoint for a single task. This shows that the touchpad is easier for the novice to operate. Every literature we found adopted a single task for its study, did not conduct or compare the experiment with simplified tasks of applications. Besides, with the restriction of the patent of trackpoint, most of the major manufacturers have adopted touchpad as the built-in input of the notebook PCs; nevertheless, some of the literatures show that the trackpoint may perform better than touchpad in specific tasks. Since human is the foundation of the design, it is necessary to integrate the relation between software hardware. According to the buttons allocation of built-in input s of the existing notebook PCs, this study will look for the suitable model of built-in input interface. In addition, considering the sensitivity of the of cursor the types of task, different combination of models will be developed. Through the parameters in the study, the adaptability on task for operating interface of each built-in input can be understood. Besides, the best combination of design parameters will be obtained. PRE-STUDY Investigation of the notebook built-in input in the market This study had investigated 15 types of built-in input s of the notebook PCs sold in the market. As the result of our questionnaire survey of left right buttons of input of notebook PCs in the market, the average long of the buttons is 30.8cm the average width is 12.4cm that were applied as the basis of our main study. STUDY APPROACH Measuring model of input Hardware The input s of notebook PCs have been divided into four modes. The interfaces (two in market, two new-developed) for these four input s are designed for right-h users. The tasks are designed for users to operate by both hs. For each interface of these four input s, blue one represents the cursor control, red one represents left button for general control green one represents right button for general control. (Refer to Table 3.1). This measuring model is IBM SK-8845 external keyboard of notebook PCs. Table 3.1 The plan of notebook PCs built-in input the actual model DB Input DP Input DH Input DS Input

3 Testing software for task design The tasks have been divided into five tasks. Task 1 Task 2 are single tasks. Task 3 Task 4 are the comprehensive tasks. Both right left hs are required to operate all the tasks. The objectives, types steps of tasks are listed in Table 3.2 as below. The tasks are operated with the 1024* 768 full screen. The resolutions of all the icons displayed in the task are the same as the default value of Windows as 32*32. Table 3.2 Details of task design Task Task 1 Multi-dir ection click Task 2 Multi-dir ection drag drop Task 3 Successi ve click select Task 4 Select drag the text Task 5 Type click the target Type of task Click Drag drop Click select Select drag Select, click type Steps of task 1. Click the Start icon 2. Click the End icon Conduct the tests 8 times in different directions 1. Drag drop the Folder to the Recycled Bin Conduct the tests 8 times in different directions 1. Click Button 1 2. Click to Button 5 in order Conduct the tests 5 times. The positions of buttons are different in each time. 1. Select drag the first appointed text 2. Perform selecting dragging to the fifth appointed text in order. 1. Type the texts punctuation marks on the first line. Proceed with the test for three paragraphs. Explanation of purpose With ISO multi-direction click assessment, it is simplified to locate each clicking target at respectively. This includes all the directions of clicking targets. With ISO multi-direction click assessment, it is simplified to locate each drag drop target at respectively. This includes all the directions of drag drop targets. According to the pre-study, all applications software contains pull-down menus for basic control they are used frequently. This task has been simplified to be successive clicking of buttons, integrated the two types of single tasks (select click) In the data processing, selecting dragging the text frequently occurred during editing. This task has integrated the two types of single tasks (select click). During the typing in general, the punctuation marks control items may also be clicked selected. This task has integrated more than two types of single tasks (select, click type) The tasks the measuring interfaces of this study are mainly written by Microsoft Visual Basic (a programming language). The general interface of the software refers to the Windows interface. The operating screen display for task 1, task 2, task 3, task 4 task 5 are shown in Table 3.3 as below. Table 3.3 The testing screen display of 5 tasks Task 1 Testing screen display of multi-direction click Task 2 Testing screen display of multi-direction drag drop Task 3 Testing screen display of successive click select Task 4 Testing screen display of select drag the text

4 Task 5 Testing screen display of type click the target Recording software The recording software written by Microsoft Visual Basic is able to record the operating time process of Task 1, Task 2 Task 3. For Task 4 Task 5, Camtasia Studio 4 (a screen recording software) is used to record the real-time screen during the task for each tester. The implementation time of the tasks, selecting dragging of the text error rate of type click the target are recorded in the experiment. In order to underst the influence of the sensitivity of cursor, the factor regarding the acceleration of cursor is not considered in this study. By changing the value of MouseSensitivity in HKEY_CURRENT_USER \ Control Panel \ Mouse, this study discusses the influence of fine-tuning of the default value. The default value in Windows XP is 10. Therefore, the value of cursor sensitivity will be set to be 8, in order to conduct the experiment. Experiment planning In the experiment of this study, there are five parameters that include modes of built-in input, type of task, sensibility of cursor, using experience the users group. Regarding the modes of built-in input s (X1), it has been divided into four levels according to the modes of built-in input s of the notebook PCs. As for the type of task (X2), it has been divided into five levels according to the types of tasks. Regarding the sensibility of cursor (X3), it has been divided into three levels according to the value of sensibility of the cursor. Regarding the using experience (X4), it has been divided into two levels according to the using experience. Regarding the users group (X5), it has been divided into two levels according to the genders. They are shown in Table 3.4 as below. Each tester has conducted 4x5x3=60 sets of experiments. The experiments have been conducted in two days there was at least one-day interval between the two days. There have been 30 sets of experiments conducted in one day. Table 3.4 Allocation table of factors for experiment Level Parameter Symbol X1 DB DP DH DS Type of task X2 Task 1 Task 2 Task 3 Task 4 Task 5 X Using Experience X4 Novice Expert Users Group X5 Male Female Steps of experiment This experiment has conducted in two different days. Half set of experiment would be

5 conducted in the first day. The rest of the experiment would be conducted in the second day. Each tester conducted the tasks sensitivity of cursor in different order. The participants had to finish all the tasks of the experiment. Before stating the experiment, all the participants would fill in their fundamental information. They would be told about the tasks, the way to operate the input precautions. The operation time process of the task would be recorded after the recording software has been started. After a set of experiment has been completed, a subjective assessment would be conducted. The Likert Seven-point Scale has been adopted for the subjective assessment. It records the four adjectives for operating the input interface: (1) Difficult - Easy to grasp, (2) Difficult - Easy, (3) Discomfort - Comfort, (4) Dislike - Like. After all the experiments have been finished, the participants would fill in the final questionnaire. Participants There are totally 30 participants in this experiment, including 17 males 13 females. According to their experience on using notebook PCs, 15 participants have been classified as experts the other 15 ones have been classified as novices. Their average age is years old. Experimental environments The operating system of the notebook PC is Windows XP SP1. The simulating built-in input of the notebook PC has been put on the notebook PC (13-inch screen, Twinhead). The experimental model has been connected with the notebook PCs through the USB. Besides, the wood board with thickness of 26mm has been added on the table to imitate the tabletop so that the imitating tabletop can fit in with the simulating built-in input of notebook PC as shown in Figure 3.1. Before the participants start the experiments, the angle the height of the chair the notebook PC s screen would be adjusted to the suitable positions of the participants as shown in Figure 3.2. Notebook PC Simulating built-in input Imitating tabletop chair table Figure 3.1 Diagram of the experimental equipments allocation Figure 3.2 Diagram of the experimental environment ANALYSIS AND DISCUSSION ON THE STUDY RESULTS Analysis discussion on factors affecting the operating time performance of error rate The results after ANOVA analyses are shown in Table 4.1. According to the Post Hoc, the operating time error rate of different tasks as shown in Table 4.2 by different built-in input s. For the sensibility of cursor in using experience users group (gender), there is no significant difference from Task 1 to Task 4. However, there is significant difference in Task 5. The main reason is that the time taken for the first four tasks is not long enough. Therefore, for the first four tasks in this study, there is no significant effect in short operating time with different

6 sensitivity of cursor. There is significant difference in Task 5 only. Besides, there is no interaction effect between the using experience, sensitivity of cursor built-in input, as well as users group, sensitivity of cursor built-in input. The results would be discussed by tasks respectively as below. Analysis on the performance of operating time error rate for Multi-Direction Click In the results of operating time, there is significant difference for different using experience built-in input s for users groups built-in input s. According to the Post Hoc, in operating time, there is significant difference for the built-in input s of DP DS with different using experience, between DP the other three input s with different users groups. Analysis on the performance of operating time error rate for Multi-Direction Drag Drop With different using experience users groups, the result shows that there is significant difference for the error rate of different built-in input s. According to the Post Hoc, there is significant difference between DP other three types of built-in input s in the error rate. Analysis on the performance of operating time error rate for Successive Click With different using experience users groups, there is significant difference for the operating time error rate of different built-in input s. According to the Post Hoc, with different using experience, there is significant difference for DP, DB DS of built-in input in the operating time between DP the other three input s in the error rate. With different users groups, there is significant difference between DP the other three input s in the operating time error rate. Analysis on the performance of operating time error rate for Select Drag the Text In the results of the operating time, there is significant difference for different using experience built-in input. With the users groups, there is significant difference for the operating time error rate of different built-in input s. According to the Post Hoc, there is significant difference for DP, DB DS, as well as DH DS of built-in input in the operating time. Analysis on performance of operating time error rate for Type Click the Target In the results of the error rate, there is significant difference for different sensitivity of cursor. According to the Post Hoc, there is significant difference for sensitivity of cursor with the value of in error rate. Table 4.1 ANOVA analyses Using experience Task1 Multi-direction click Dependent variable Independent variable P value Users group Dependent variable Independent variable P value Using experience 0.009* Users group 0.000* cursor 0.000* 0.000* Using experience Users group 0.284

7 cursor Task2 Multi-direction drag drop Using experience 0.56 Users group 0.54 cursor Using experience 0.56 Users group Task3 Successive click cursor 0.000* 0.000* Using experience Users group cursor 0.004* 0.002* Using experience Users group cursor Taxk4 Select drag the text 0.03* 0.003* Using experience 0.003* Users group cursor 0.002* 0.001* Using experience Users group cursor Task5 Type click the target *: p< * Using experience 0.84 Users group cursor Using experience Users group cursor * Table 4.2 Operating time error rate of tasks DB Task Using experiences Novices operating time error rate Users groups Male operating time 0.048* error rate Multi-direction click Multi-direction drag drop E E-02

8 Successive click E E-02 Select drag the text E E-02 Type click the target E E-02 Multi-direction click DP DH DS Multi-direction drag drop Successive click E E-02 Select drag the text E E-02 Type click the target E E-02 Multi-direction click Multi-direction drag drop E Successive click E E-02 Select drag the text E E-02 Type click the target E E-02 Multi-direction click E-02 Multi-direction drag drop E E-02 Successive click E E-02 Select drag the text E E-02 Type click the target E E-02 Experts Female Task operating time error rate operating time error rate Multi-direction click DB DP DH Multi-direction drag drop Successive click E E-02 Select drag the text E E-03 Type click the target E E-02 Multi-direction click Multi-direction drag drop Successive click E E-02 Select drag the text E E-02 Type click the target E E-02 Multi-direction click E E-02 Multi-direction drag drop E-02 Successive click E E-02 Select drag the text E E-02 Type click the target E E-03 Multi-direction click Multi-direction drag drop DS Successive click E E-02 Select drag the text E E-03 Type click the target E E-03 Analysis on attitude of users Analysis on subjective assessment of users The subjective assessment of users in this study includes satisfaction of interface, understing of interface subjective assessment of the interface. After finishing the first set of experiment, the participants would conduct the subjective assessment at once. Through the terms Easy to grasp Difficult, the participants satisfaction of

9 the interface could be understood. The terms Easy - Difficult" have been used to underst the participants comprehension of the interface. The terms Comfort Discomfort Like Dislike have been used to underst the feeling of the participants after the experiment is studied with the mentioned approach. The result shows that most of the participants prefer the task of DS built-in input some specific tasks. On the other h, their preference for task of DP built-in input some specific tasks are lower. Analysis on subjective assessment of task operation After finishing the experiment, the participants would conduct the subjective assessment of built-in input sensitivity of cursor. It is found that it is easy to grasp when the sensitivity value of cursor for DS input is 12 the sensitivity value of cursor for DS input is 10. It is relatively difficult to operate the DP built-in input. For the comfort assessment of the participants, it is found that the participants feel more comfortable when the sensitivity value of cursor for DS input is 12 the sensitivity value of cursor for DS input is 10. It is relatively not comfortable when the sensitivity value of cursor for DP input is 12. It is more comfortable to operate the DS input. It may be because the s operating room for the both hs is bigger touchpad is easier to be controlled than the trackpoint. For the subjective assessment of difficulty of each task for participants, it is found that when the sensitivity value of cursor for DS built-in input is 12, the participants feel easier for Multi-Direction Click Multi-Direction Drag Drop. In any of the task, participants feel uncomfortable on task of DP built-in input. For the subjective assessment of built-in input, sensitivity of cursor preference of task, it is found that the top two scores of each item are DS-12 or combination of DS-10 DH12. The preference of DP12 combination of DP-10 DP-08 is lower. Analysis on adaptability of built-in input for users After finishing all the experiments, the participants would be asked which notebook PCs input has been the most suitable for each task. Among them, 19 participants feel that DS is suitable for Multi-Direction Click, 17 participants feel that DS is suitable for Multi-Direction Drag Drop, 18 participants feel that DS is suitable for Successive Click Select. Furthermore, 15 participants feel that DS is suitable for Select Drag the Text 15 participants feel that DS is suitable for Type Click the Target. CONCLUSION Performance of operating time As the result of experiment shows, the experts novices are both young participants so that they can be accustomed to the sensitivity of cursor on each task rapidly. However, for the built-in input, there is significant difference for DP the other three built-in input s. It is obvious that the novices can easy to grasp the built-in input of touchpad. On the other h, it takes longer time to get used to the trackpoint. According to the study from Christine (2005), the novices using trackpoint spent longer time than that who using touchpad does to complete the task. This conclusion accords with the experiment results of this study. For the operating time of different genders using the built-in input of notebook PCs, there is significant difference between DP the other three built-in input s. It is not easy for females to control the strength of fingers when they use the trackpoint. Therefore, they have taken longer time than males to finish the task when they conducted the trackpoint experiment.

10 For the using experience users groups, the results show that there is significant difference in the error rate of operating different built-in input in Task 2 Task 3. This represents that the newly developed built-in input is easier than the existing ones to control the cursor click. Besides, for different genders, there is significant difference between DP the other three built-in s in the error rate of operating built-in input. It is not easy for female to control the strength of their fingers when they use the trackpoint. Therefore, females have been easier to make mistakes than males do when they conducted the trackpoint experiment. Assessment on hardware interface design The results from this study show that most of the participants have higher assessment on DS DH built-in input mode of notebook PCs the sensitivity value of whose cursor is over 12. It is different from the built-in input default value of notebook PCs in the market. Though there is no significant difference in objective score, there is significant difference in subjective assessment from participants. Reference Accot, J., Zhai, S., 1999, Performance Evaluation of Input Devices in Trajectory-based Tasks: An Application of The Steering Law, Chi 99, Kate Ehrlich, 1997, A conversation with Ted Selker pp Akamatsu, M., MacKenzie, S., 2002, Changes in applied force to a touchpad during pointing tasks, International Journal of Industrial Ergonomics 29 (2002), Chaparro, A., Bohan, M., Fernez, J., Choi, S.D., Kattel, B.,1999, the impact of age on computer input use: Psychophysical physiological measure, International Journal of Industrial Ergonomics 24 (1999), Clements, D.H., 1987, Computers young children: A review of research, Young Children, 43(1), Fernstrom, E., Ericson, M.O., 1997, Computer mouse or Trackpoint effects on muscular load operator experience, Applied Ergonomics 28 (1997), Kelaher, D., Nay, T., Lawrence, B., Lamar, S. Sommerich, A., 2001, An investigation of the effects of touchpad location within a notebook PCs computer, Applied Ergonomics 32 (2001), Sommerich, C.M., Starr, H., Smith, A., Shivers, C., 2002, Effects of notebook PCs computer configuration task on user biomechanics, productivity, comfort, International Journal of Industrial Ergonomics 30 (2002), 7-31 Sutter C., Ziefle M., 2005, Interacting with Notebook PCs Input Devices: An Analysis of Motor Performace User s Expertise, Human Factor Ergonomics Society, Patent Apple Computer, Inc, Apparatus method for providing different input orientations of a computer system, 1995, US patent #5,469,194 International Business Machines Corporation, Keyboard with integrated pointing click buttons with lock down for drag operation in a computer system with a graphical user interface, 1997, US patent #5,694,123 International Business Machines Corporation, Low Noise Circuit Board for trackpoint pointing, 1999, US patent #6,195,082 B1 International Business Machines Corporation, Pointing with reciprocating grip cap, 1999, US patent #5,870,082