independent variable receives a slightly different treatment, some researchers
refer to the independent variable as the treatment variable.
Adependent variable is measured by the investigator and used to compare
the experimental groups. In a well-designed study, differences among groups onthe dependent variable can be attributed to the different levels of the indepen-
dent variable. Returning to the anxiety example, suppose the researcher ’s
hypothesis was that people reduce anxiety about upcoming events by obtaining
as much information about the situation as possible. The researcher might use
level of anxiety as the independent variable, creating high-, moderate-, andlow-anxiety conditions. The three groups might be compared on how many
questions they ask the experimenter about the upcoming event. In this case, the
number of questions is the dependent variable. The results of such an experi-ment might look like this:
High
AnxietyModerate
AnxietyLow
Anxiety
Average
number of questions 5.44 3.12 1.88
If the experiment has been designed correctly, the investigator will attri-
bute
the difference in the dependent variable (the number of questions) to the
different levels of the independent variable (anxiety). Because experimenters
want to say that differences in the dependent variable are the result of the
Many personality researchers conduct laboratory studies to test their hypotheses.
These investigations typically take place in university settings, often with undergraduatestudents as participants and graduate students as experimenters.The Hypothesis-Testing Approach 23