Homework #8:
(Due 05/10/05)
Measuring Fitts' law using a mouse
Overview
For this homework you will build a simple
interface to measure Fitts' law parameters. For this simplified
experiment, you will measure how fast a user can point between 2
squares shown on the screen for different value of the index of
difficulty (ID).
What you have to do
-
Design the experimental protocol to run the
study.
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Design a simple interface to measure Fitts'
law parameters. The interface should:
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for each trial, present
a start-up screen so that the user can get ready;
-
for each trial, present
a pairs of squares on the screen and let the user first click
inside the left most square then click back and forth between
the 2 squares as fast as they can for at least 10 times (users
need to click inside the square each time);
-
for each trial, record the time it took
the user to click between the 2 squares (10 samples are recorded);
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for each
trial, present a completion screen;
-
present a
series of trials spanning the index of difficulty from 2 to 6.
For each index of difficulty, your program should measure at
least 3 possible width/distance combinations. Since you are
recording 10 action per condition, your system should at least
record 150 trials per users;
-
present a completion screen at the end of
the test.
-
Implement your
design. See below for the implementation guide lines;
-
Run your
protocol for at least 5 different users. (If you are using fellow
students as subjects you don't need to apply for a human subject
protocol review);
-
Write a report describing your experimental
findings.
Implementation
For this project, you have to choose the
specifics of how to implement your project within certain limits.
Platform
All projects must be able to run under Windows
XP, or 2000 (or NT). You can expect that the machine you
will be running your project on will have a Java 2 virtual
machine, and can execute Flash web pages. Finally you can expect
the computer to have at least a CD-ROM drive.
Software
You are free to pick any programming languages
(C++, Virtual Basic, C#, Java, Flash, Director...) and
development environment you wish as long as the resulting
program runs on the configuration described under the Platform
section.
Deliverables
Your homework should contain:
-
(40 points) A description of your protocol
including:
-
your
hypothesis;
-
the
independent and dependent variables;
-
the
possible confounding variables in your setting;
-
your
target population and the consent form you used;
-
how you ran each subjects (including the
check list followed by the experimenter);
-
(20 points)
The executable code (in running order). Please, specify accurately
your platform, operating system, language used, needed software,
which file to run;
-
(20 points) A presentation of your
experimental results including:
-
a graph showing
for each ID the average "connection" time for each users;
-
a graph showing
for each ID the average "connection" time across all users as well as
the trend line;
-
a description of any problem you might have encountered
during the experiment.
-
(20 points) An explanation of the
discrepancies between predicted and measured times.
No statistical analysis is necessary for this
homework.
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