Information and Computer Science — UC Irvine — David G. Kay — Informatics 131

SECOND HOMEWORK

(a) Read Bruce Tognazzini's article, "A Quiz Designed to Give You Fitts." There's a lot of interesting material at his asktog.com site.

Look over the "Perception in Visualization" page by Christopher G. Healy. You don't have to read the entire text, but you should scan the examples and spend a few minutes playing with each of the two interactive demonstrations on the page.

There's nothing to turn in for this part, but these ideas may show up later.

(b) (optional) Do this on-line demo illustrating Fitts' Law. It doesn't include much explanation, but the task should give you a tangible understanding of the principle behind Fitts' Law. There's nothing to turn in for this part.

(c) In class this week we have discussed these topics, among others:

• Miller's 7 +/– 2 items (capacity of short-term memory)
  
• Pre-attentive processing, gestalt laws
• Fitts' Law
  
• Graphical coding
  
• Anthropomorphism
• Affordances

Pick three of these six topics; for each of the three, choose an example from your HCI notebook that illustrates the topic (or find an example from your own experience if your notebook doesn't have one). Don't choose examples we discussed in class or that come directly from the readings. Your examples may show a misapplication or misunderstanding of the principles or may be a particularly good example; in either case, describe and analyze each example using the terms and guidelines that pertain to the topic it illustrates. If your example is a negative one, suggest an improvement and describe why your suggestion is better.

A dozen pithy lines of text should be sufficient for each of the three examples (where "pithy" means clean, clear, well-organized, terse, and not padded); half a page for each is an absolute maximum. (Again, this refers just to the text; you will probably use more than half a page each if you count illustrations.)

(d) One measure of user efficiency for certain systems is to count the number of steps or keystrokes that common operations require.

Monitor your own cellphone usage over at least two full days. What are the (four or five) most common tasks you perform (making a call, sending a text, ...)? Treat tasks that have different keystroke sequences (like phoning someone from your contact list vs. phoning someone by typing in their phone number) as separate tasks. For each of your common tasks:

• How many keystrokes does the task take? [For some tasks, like playing a game or sending text message, the total number of keystrokes depends on the game play or the particular message. In those cases, just count the other keystrokes—what it takes to select and launch the function (and to quit it at the end). On some phones, the user makes gestures instead of or in addition to keystrokes; if your phone is like that, you can count gestures, but a gesture typically conveys more information than a single keystroke.]
• Does the task require visual confirmation or can you do it all with audio and tactile feedback? (In other words, could you do this task while keeping your eyes on the road?)

You can use your HCI Notebook to record this information (since you're carrying it with you at all times, right?).

A simple table would be enough to communicate your results for this part.

(If you don't have a cellphone, check with us for an alternative.)

(e) How many different items have you recorded in your HCI notebook so far? We'll give full credit for any truthful answer to this, even zero, but we'd like to know how much use the class is making of these notebooks.

(f) This part is preparation for a later assignment. You can do it before, during, or after this week's class meeting.

Pick a partner who is also enrolled in the class. Together, find three different application programs that perform the same function. Choose applications that do something relatively simple: Rather than a word processor or a database or a graphics editor, choose a desktop calculator, a virtual alarm clock, a Shanghai game, an instant messaging client, or any other single-function tool. Identify three different versions (perhaps using shareware sources on the Internet; nobody should have to purchase anything for this assignment) and install them on a machine (or machines) you can use. It would also be acceptable to choose three web sites with similar aims (e.g., the travel sites Expedia, Orbitz, and Travelocity), though they may be more complex than single-function applications.

In a later assignment, we will ask you to compare the user interfaces of these applications. They are likely to have some differences in functionality, but we will ask you to concentrate on tasks that all three perform and the HCI aspects of those comparable tasks. For now, though, just find a partner, decide on an application category, and locate and install the software (or locate the web sites). You don't need to turn anything in for this part.

Combine all your answers into one electronic document (making sure your name, student ID number, and UCInet ID are at the top) and submit it via Checkmate.

Written by David G. Kay, Winter 2004; modified Summer 2008 and Summer 2013.