typically generate a new theory or modify the old one to better account for
the research findings.
Experimental Variables
Good research progresses from theory to prediction to experiment. The basicelements of an experiment are the experimental variables, which are divided
into two types: independent variables and dependent variables. An indepen-
dent variable determines how the groups in the experiment are divided. Often
this is manipulated by the experimenter, such as when participants are ran-
domly assigned to different experimental conditions. An independent variable
might be the amount of a drug each group receives, how much anxiety is cre-ated in each group, or the type of story each group reads. For example, if
level of anxiety is the independent variable, a researcher might tell Group A
that they will give a speech in front of a dozen critical people, Group B thatthey will give a speech in front of a few supportive people, and Group C
nothing about a speech. Because each of the groups created by theLoneliness is caused by lack of social skills.
Prediction: Lonely people don’t initiate as many 
conversations as nonlonely people.
Prediction: Lonely people make more socially inappropriate
statements than nonlonely people.Lonely people have less accurate perceptions
of how people see them than nonlonely people.Theory:
Prediction:
Test: Have judges count the number of inappropriate
statements made by lonely and nonlonely peoplein a conversation with a stranger.
Test: Ask roommates of lonely and nonlonely peopleto evaluate the frequency of inappropriatestatements.
Test: Construct a test of the rules governing appropriateand inappropriate social statements; administerthe test to lonely and nonlonely people.
FIGURE 2.1 Example of the Hypothesis-Testing Approach22 CHAPTER 2 Personality Research Methods