An Exploration of Techniques to Improve Relative Distance Judgments within an Exocentric Display

Appendix A

Experiment 1 Overview

This experiment is designed to test how different computer graphics features impact your ability to make distance judgments on a computer screen. The purpose of this experiment is to determine which computer graphic features are most helpful in allowing you to make judgments that are both accurate and rapid.

During the experiment, you will be asked to look at a visual scene and indicate (with the keyboard) which of the 4 differently colored cubes is closest to the white cube. You will need to make each judgment as quickly and accurately as possible.

At different points in the experiment, however, you will be able to use different computer graphic features to help you make these judgments. I will be telling you which features will be available at the appropriate time. You will also be given small breaks at these different intervals. If at any time you would like a longer rest, please let me know and you will be given a longer break. The complete experiment will take approximately one hour and 15 minutes. If at any time you would like to withdraw from the experiment, please let me know and you will be excused without any penalty.

You will first perform 5 practice trials (judgments) where you will be given feedback as to whether or not you selected the closest cube. After the practice trials have concluded, you will not be told whether or not you are making correct judgments. During the practice trials you will be able to use all of the computer graphic features being tested so that you can become familiar with each of them.

Indicating the closest cube:

In order to specify which colored cube is closest to the white cube, press the following keys which are in the upper left portion of the keyboard:

press 1 if BLUE is closest,

press 2 if PINK/LAVENDAR is closest,

press 3 if GREEN is closest,

press 4 if YELLOW is closest.

These keys will also be marked with these colors on the keyboard itself. If you feel you have pressed a key in error (for example, you pressed 3 when you meant to press 2), please let me know before you press any additional keys.

Using the computer graphic features:

During the experiment, you will able to perform the following actions:

Rotation

Rotation will allow you to rotate (or change the view of ) the image within the display by using keys 1 through10 that are on the number pad on the right side of the keyboard. Number 5 (in the center) is a special key that will return the image to the original view which is shown at the begining of each trial.

Head Motion Tracking

When head tracking is on, the computer display will respond appropriately to movements of your head.

I will explain these features again once we begin.

Before beginning the experiment, you will be tested to determine if you have the ability to see in stereo and to determine your ability to properly indicate the colors of the cubes.