CMSC434: Introduction to Human-Computer Interaction

Exam #2 – November 11, 2004

Exam is closed book, closed notes, 75 minutes—Total points: 100

(Please write legibly! Your grader appreciates it!)

For the following questions (1-4), clearly write the letter of your answer in your test booklet.

1. Why can designing a system for cooperation be a challenge?

A. People generally do not want to cooperate, as they find it unsatisfying and unproductive.

B. Balancing the subtle questions of trust, etiquette, deceit and potentially abusive behavior.

C. There hasn’t been any research done on cooperation due to the multiplicity of users.

2. For which type of users are anthropomorphic characters typically harmful/

A. Users with external locus of control.

B. Users with internal locus of control.

C. Children.

3. Fitts’s Law is a predictive model of time. What does it predict?

A. The number of words-per-minute a user can type.

B. The speed at which the data density of circuits increases over time.

C. The time it takes for a computer to audibly output a text document.

D. The time it takes to point to a target based on width and distance.

4. When is form fillin a more attractive approach than menu selection?

A. Choosing an item from a list.

B. When a command is frequently used.

C. Data entry of text or numeric values.

D. When the grouping and sequence of menu items needs to be optimized.

5. You are in charge of designing a menu tree for a used car dealership with about 2000 cars. Should the menu tree be narrow and deep or broad and shallow? Give two reasons to back up your choice. Draw a sample tree of each type(narrow and deep; broad and shallow); label the branches to give an idea of the organizational breakdown. (16 points)

6.

A. Describe the difference between asynchronous distributed interfaces and synchronous distributed interfaces. (4 points)

B. Give two examples of each (asynchronous and synchronous distributed interfaces) (4 points)

C. Which collaborative interface, of the four types, has been the best one to use for your semester long group project? Explain why in a short paragraph. (6 points)

7. Describe four distinct ways to reduce the user frustration levels of computer users. (8 points)

8. Use the following command language to answer this question.
Name/usage Abbreviation Description
write <fn> w <fn> send file to printer
save <fn> <loc> s <fn> <loc> save file to location
copy <fn> <loc> c <fn> <loc> copy file to location
open <fn> o <fn> open file
tape <fn1> <fn2> t <fn1> <fn2> append second file to first file
glue <fn1> <fn2> g <fn1> <fn2> append second file to first file

A. Name two command language guidelines that are violated by the above command language. Explain how each guideline is violated. (8 points)

B. Name two command language guidelines that are followed by the above command language. (4 points)

9. Previously, people thought that computers understanding spoken words was the future.

A. Describe three problems with speech recognition systems. (6 points)

B. Describe three beneficial situations for using speech recognition systems. (6 points)

10.

A. What are the three primary factors that influence users’ expectations and attitudes regarding response time? (6 points)

B. Under what situation would a slower response time be appropriate. Explain your answer. (4 points)

11.

A. Write four guidelines for the design of effective error messages in a software product. (8 points)

B. Describe the problem in each of the following error messages. Briefly state your reasoning and suggest a better message or a way to make the message better. (2 points each)

i. Your cell phone is out of range with any tower. The following error message appears when you try to make a phone call:
ERROR CODE 2594

ii. You are trying to log into your favorite online blog, and you enter the wrong password. The following error message appears instead of the page:
Authorization Required: You are not good enough to enter this web site until you prove yourself worthy.

12. Color displays are attractive to users and can often improve task performance, but the danger of misuse is high. List four guidelines for using color and give an example of how each can be used in a color PDA display. (8 points)