Research Methods ❮ 75❯ rapid review
Theories—organized sets of concepts that explain phenomena.Hypothesis—prediction of how two or more factors are likely to be related.Replication—repetition of the methods used in a previous experiment to see whether
the same methods will yield the same results.Independent variable (IV)—the factor the researcher manipulates in a controlled
experiment (the cause).Dependent variable (DV)—the behavior or mental process that is measured in an
experiment or quasi-experiment (the effect).Population—all of the individuals in the group to which the study applies.Sample—the subgroup of the population that participates in the study.Random selection—choosing of members of a population so that every individual has
an equal chance of being chosen to participate in a study.Experimental group—the subgroup of the sample that receives the treatment or inde-
pendent variable.Control group—the comparison group; the subgroup of the sample that is similar to
the experimental group in every way except for the presence of the independent variable.Table 6.1 Overview of Research Methods
Research
Method Description Key Strength Major Weakness
Experiment Manipulation of an Can establish cause and Ability to generalize to
independent variable (IV) effect relationships between real-world behavior can
under controlled conditions the IV and the DV be limited
and measurement of its
effects on a dependent
variable (DV)
Quasi- Measurement of a DV when Can provide strong evidence Lack of random assignment
experiment random assignment to suggesting cause and effect can weaken conclusions
groups is not possible relationships
Naturalistic Careful observations of Provides descriptive data Loss of experimental
observation humans or animals in about behavior with control
real-life situations wide applicability
Surveys and Obtain large samples of Ease of administration, Distorted results because
Tests abilities, beliefs, or scoring, and statistical of sampling error, poorly
behaviors at a specific analysis phrased questions, and
time and place response biases
Case studies Intensive investigation of Provide detailed descriptive May not be representative
the behavior and mental data and analyses of new, of phenomena
processes associated with a complex, or rare phenomena
specific person or situation