The most important control variable in a psychophysics experiment ...

[dmcintosh]

The most important control variable in a psychophysics experiment is
 
  a. the stimulus magnitude.
  b. the stimulus duration.
  c. the participant's criterion.
  d. the participant's ability.

Question 2

In a study with a group of individuals being tested in a series of treatment conditions that extends over a relatively long time, it is possible that there will be systematic changes in the participants' physiology or psychology that occur during the time of the study. When these changes influence the participants' scores, causing scores at the end of the study to be different from scores at the beginning, the effect is called ____.
 
  a. history
 b. instrumentation
 c. maturation
 d. regression toward the mean

[mariahkathleeen]

Answer to Question 1

C

Answer to Question 2

c

[dmcintosh]

Excellent

[xiazhe]

Gracias!