Yohanes Suliantoro ysulian2 CS465 HW#2

Transcription

1 Yohanes Suliantoro ysulian2 CS465 HW#2

2 No 1. Portable gaming device (Nintendo DS lite) The NDS is usually used by people who wants to play game on the go. This consideration made the console small, lightweight and have long battery life. I think in those 3 areas, the designers have done quite well. The console is quite small and thin especially compared to other gaming device such as PSP. The battery life is also quite long. However the weakness of the design is that the stylus holder is quite loose, thus the stylus can easily fall out if the side of the console is hit. The screen itself is not so good when there is sunlight. There should be glare reducing screen. The placement of the microphone on the NDS lite I think is worse than the one on the original NDS. On the NDS lite, the microphone is placed in between the 2 screens, whereas on the original NDS, the microphone is placed on the bottom of the lower screen. I think the microphone on the original NDS works better since while we are using the microphone we can still see both screen. On the NDS lite, we cannot see the bottom screen when we are using the microphone. Digital watch Digital watch is usually worn in a casual place. The watch usually include multiple functionalities such as stopwatch, timer, showing date, changing time zone, alarm and light. In this sense, the designer have fulfilled their goal, having a lot of functionalities in a small device that can be worn everywhere. The digital watch works perfectly as a watch, as usually the numbers are shown in large font size. Digital watch usually have light which can sometimes be used as a light source. The downside of it, digital watch usually have 3-4 buttons in it. One on top right corner, bottom right, top left and bottom left. It is very confusing which button performs what function. Changing the setting of the watch is also quite painful thing to do. Some of the digital watch tries to pack a lot of information on the small screen and as a result, none of them can be seen or useful to look at all the time. Game pad Controller Game pad are designed so that when a person with average size hand holds it, the person can comfortably grip the controller and access all the buttons easily. In both these aspects, the designers are successful. Controllers like the Xbox360 controller and PS3 controller usually fit firmly to most user and all the buttons are accessible easily. Another strength of the controller is that they usually are quite robust. The weaknesses of these controllers are numerous buttons, and they are usually quite heavy. The numerous buttons on a game pad controller might be necessary for some gamers, but to new user, these numerous buttons can be very confusing, since these controllers usually have numerous right and left side buttons which is numbered by PS as L1, L2 and R1, R2 and Xbox called it RB, RT and LB, LT. This naming convention is very hard to differentiate since the label for the buttons cannot be easily seen without tilting the controller. The weight of the controller is usually associated with the capability to vibrate. Some user might prefer lightweight controller rather than vibrating controller.

3 No 2. An itunes user encountered several problems while using the application. The first one is that the application always sort all the music in alphabetical order, which isn't necessarily what the user wants. This makes the user frustrated when trying to find a song if they don't know the keyword to search with. Another problem is the absence of keyboard shortcut. User has to open the itunes window and press the buttons there, as supposed to winamp which allows global shortcut. The pull-down menu can also be confusing and not so intuitive when trying to find a certain functionality. A user encountered some problems when using Microsoft Office One of the problem was the new menu interface. The use of large icons as menu sometimes confuse the user with seeing too much things on the screen. Another disadvantage of this type of menu is that the icons don't necessarily help user to determine what happens when they press those icons. The complete redesign of Office makes user confused because of total layout redesign. Thus they have to learn where everything is all over again. Paint is another application that user have trouble with. The limitation of what the application can do sometimes renders the application useless. Some of the frustration includes the difficulty of doing something such as cropping an image, which is something that can be done easily in Adobe Photoshop. Also the frustration comes when trying to insert a text, if they accidentally press something else while they haven't finished typing in the text, there is no way we can bring back the text box again. The problems usually comes around the fact that some simple mis-click can lead to a frustration because of the difficulty in undoing something.

4 No 3. # Correctness Time (ms) 1 FALSE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE FALSE TRUE TRUE TRUE TRUE TRUE TRUE TRUE 2592

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6 6000 Time vs Number of trials Time (ms) Number of trial T1 = 5104 ms T20 = 2592 ms n = 20 Therefore, learning constant (alpha) = Note: I calculate alpha using T1 as the time for first trial and T20 as time of the last trial. The subject uses his primary hand (right hand) to type. He says the letter that he's typing to help him type faster.

7 No 4. a. Using Fitts' Law Response time = a + b log(d/w + 1) Assume D = on average 1/4 of screen diagonal length Assume W = the menu has large buttons about 1/12 screen size Response time = a + b log(1/4 / 1/12 + 1) b. To simulate where the menu is 50/50, the response time will be the same as before for the static menu, but for the dynamic menu, it will be longer since user will need to figure out where the item is placed. When the probability is 75/25, the response time will be even slower because the chance of the menu being placed in an unexpected place will be bigger. The 90/10 will have the largest response time compared to the others. The minimum choice time will be almost instantaneously if the user's pointer is already near the target. 100/0 will have the maximum choice time since the menu will be completely random, thus the user will have maximum choice time. c. Hick's law doesn't apply to a randomly organized buttons which require user's knowledge about the location of a button.