Refer to the Human Factors (Dec. 1988) study of color brightness as a body orientation clue, Exercise 7.65. Ninety college students, reclining on their backs in the dark, were disoriented when positioned on a rotating platform under a slowly rotating disk that blocked their field of vision. The subjects were asked to say “stop” when they felt as if they were right     side up. The position of the brightness pattern on the disk in relation to each student’s body orientation was then recorded. Subjects selected only three disk brightness patterns as subjective vertical clues: (1) brighter side up, (2) darker side up, and (3) brighter and darker side aligned on either side of the subjects’ heads. The frequency counts for the experiment are given in the accompanying table. Construct a 95% confidence interval for the difference between the proportion of subjects who select brighter side up and the proportion who select darker side up as vertical clues. Interpret the results.    

Data from Exercise 7.65

Astronauts often report episodes of disorientation as they move around the zero gravity spacecraft. To compensate, crew members rely heavily on visual information to establish a top-down orientation. An empirical study was conducted to assess the potential of using color brightness as a body orientation cue (Human Factors, Dec. 1988). Ninety college students, reclining on their backs in the dark, were disoriented when positioned on a rotating platform under a slowly rotating disk that filled their entire field of vision. Half the disk was painted with a brighter level of color than the other half. The students were asked to say “stop” when they believed they were right-sideup, and the brightness level of the disk was recorded. Of the 90 students, 58 selected the brighter color level.

Transcribed Image Text:

BODYCLUE Disk Orientation Brighter Side Up Darker Side Up Bright and Dark Side Aligned 58 15 17