To eliminate the possibility, psychologists use counterbalancing,a procedure that assigns
half the subjects to one of the treatments first and the other half of the subjects to the other
treatment first.Quasi-experimental Research
Quasi-experimentalresearch designs are similar to controlled experiments, but partic-
ipants are not randomly assigned. Experimental research designs to study differences in
behavior between men and women, boys and girls, young and old, or students in one class
and students in another class are “sort of ” experiments or quasi-experiments. Because of
confounding variables—preexisting differences between the experimental group and com-
parison groups—quasi-experiments do not establish cause and effect relationships,
although they can point in the direction of them.Correlational Research
Although experiments conducted under carefully controlled conditions help establish cause
and effect relationships, the time, expense, and artificiality of the environment limits that
type of research. Psychologists more often use descriptive and correlational research meth-
ods such as survey methods that involve interviews or questionnaires, tests, and naturalistic
observation. Correlational methods look at the relationship between two variables without
establishing cause and effect relationships. The goal is to determine to what extent one vari-
able predicts the other. Many factors that seem to be causally related are not. Often it’s a
third factor that causes the other two.Naturalistic Observation
Naturalistic observation is carried out in the field where naturally occurring behavior can
be observed. Naturalistic observation studies gather descriptive information about typical
behavior of people or other animals without manipulating any variables. For example, Jane
Goodall’s team of scientists has been observing the behavior of chimpanzees in the wild for
decades. Such studies have enabled scientists to predict when the chimps will fight each
other or when they will mate. Similarly, other scientists have been studying human behav-
ior in the workplace, in schools, in bars, etc. The data can be used for correlational analy-
sis or for generating ideas for other research.Survey Method
In the survey method,researchers use questionnaires or interviews to ask a large number
of people questions about their behaviors, thoughts, and attitudes. In order for the infor-
mation to be useful, the participants in the study should be representative of a larger pop-
ulation, which can best be achieved by random sampling. Accuracy of data is an issue
because people sometimes distort their answers to appear more “politically correct,” or they
fail to recall information correctly. The data from surveys can be used for correlational
analysis or for generating ideas for other research.
Retrospective or ex post factostudies look at an effect and seek the cause. For exam-
ple, when researchers found an increase in babies being born with deformed limbs, espe-
cially in England but also in the United States and other western countries in the early
1970s, they asked the mothers of the babies many questions, then compared the answers of
all of the mothers through correlational analysis. They found the strongest relationship
between the mother taking the drug thalidomide during the pregnancy and the appearance
of the limb deformities in the babies. Controlled experiments with rodents verified that the
drug caused abnormal limb development in the babies of the animals.54 ❯ STEP 4. Review the Knowledge You Need to Score High