Develop an interval recording sheet similar to the one in Figure 5.8. However, instead of having five rows with six 10-second intervals, make it with five rows of six 30-second intervals. Your recording sheet should give you a total observation time of 15 minutes. Make two copies of this sheet. At the top write “Running.” Then invite a friend over to watch some sporting event on television that involves some running.

Take off your watch, set it to beep at 30-second intervals, and place it on a table close to you and your friend. Tell him or her that you’re playing a game to see who can most accurately note when some athlete on television is running, and that when running occurs he or she should mark the corresponding box with an “X.” At the end of the 15-minute session, you and your friend should figure out the percentage of intervals running occurred. Finally, you and your friend should use the formula for interval recording to calculate the interobserver reliability. Did the reliability between you and your friend reach 80 percent? If not, to what factors do you attribute the low reliability?