Theory of Motivation. Experimentation in psychological research. The fallibility of human reason in everyday life. Designing Social Inquiry. D'Amato discusses the first three designs in some detail.
Authors are justified in describing a phenomena.
Authors are justified in stating that a relationship may exist between certain predictor and criterion variables, but the design and results from a single study do not justify stating that a causal relationship exists. If the study is conducted in such a way that threats to internal and external validity are minimized, then the experimenter is justified in stating that the independent variable is causally related to the dependent variable. This type of design is the most controversial. In some instances it is reasonable to infer causality. None listed for this unit.