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-
- Fitt's Law Experimenter
-
- Preface
-
- I wrote this program as an assignment for a graduate course in computer
- graphics here at the University of British Columbia. Basically, this
- program runs a psychology experiment to see how quickly and accurately
- human subjects can select menu items for various types of pop-up menus.
- This data can then be used to suggest better types of menu design for user
- interfaces, based on human performance.
-
- While the program features an interesting "menu builder" window with some
- cool controls, it is my first NeXTSTEP application. Thus, beware of the
- programming style and object decomposition. Also, since this really is
- just an assignment for a school course, it's a toy. There are probably
- a few bugs, too.
-
- This software was written under NeXTSTEP 2.1, and is released to the
- public domain.
-
- I can be contacted at:
-
- NeXTMail: bowen!stuart@cs.ubc.ca
- ASCII: sritchie@cs.ubc.ca
- Snail: Stuart Ritchie
- 2034 West 35th Ave.
- Vancouver, BC
- Canada V6M-1H9
-
-
-
- What is Fitt's Law?
-
- Fitt's Law describes human motor skill performance.
-
- Many computer users are well associated with graphical user interface
- environments. These environments are designed to be friendly to new users
- and efficient for experienced ones -- often, these are conflicting goals.
-
- Various experiments have been performed to determing the optimal layout
- for user interface menus in terms of human performance. These experiments
- break down human performance into various categories, such as perceptual,
- cognitive and motor components. Specifically, Fitt's Law predicts that
- increasing either the distance to the target or the size of the target causes
- the time to acquire the target to increase.
-
-
- What is this program?
-
- This program allows an experimenter to construct various styles of popup
- menus, and conduct trials to collect performance data from human test subjects.
- The data collected can be used to compare against Fitt's Law.
-
- Three types of popup menus can be created: stacked horizontal, circular pie
- shaped, and circular rectangular shaped. Many geometric aspects of
- these menus can be interactively arranged in real-time on NeXTSTEP.
-
-
- How to use the Fitt's Law Experimenter
-
- 1. Start Fitts by double clicking from the Workspace.
- Two windows will appear: Experiment Control, and Experiment.
-
- 2. Experiment Control is used to manage the experiments. The main feature
- in this window is the Menu Field, which displays the current menu based on
- settable parameters below. The Menu Type buttons select which type of popup
- menu is to be used. Menu Sizing allows the sizing and geometry of the
- menus to be changed. General Options allows the number of menu items and
- colours to be configured. Finally, Experiment Options configures the
- test case manager. Test case results are fed to a file named by the
- Experiment ID field.
-
- 3. After setting up the menu to an appropriate style, hitting the GO
- button will allow the experiment to start.
-
- 4. Select the Experiment window.
- The Menu View in this window is used to display the popup menu to the
- test subject and record their menu selections. Pressing the Ready button
- will start the experiment. A square will appear in the center of the Menu
- View. Pressing (but don't release) this square will cause the menu to pop
- up. Drag the pointer to the highlighted menu item and release the mouse
- button. This selecting will continue until the number of specified trials
- has been reached.
-
- 5. Each of the trials is recorded to a Unix file. This file can be
- imported to a graphing package for display and analysis. The file name
- for the trial file is specified in the "Experiment ID" field of the
- Experiment Control window.
-
-
- Installation
-
- Just use "make" to build the application. The executable "Fitts"
- does not require any auxilliary files or application wrapper.
-
-
-
-
- References:
-
- James Boritz, Kellogg S. Booth, William B. Cowan, "Fitt's Law Studies of
- Directional Mouse Movement", Graphics Interface '91.
-
- Fitts, P.M., "The Information Capacity of the Human Motor System in
- Controlling the Amplitude of Movement", Journal of Experimental Psychology,
- Vol. 47 (1954), No. 6, pp. 381-391.
-
-