The research designs for abnormal psychology may be experimental or correlational.
• Correlational research examines as is factors, while experimental research involves manipulating of independent variable and studying the effect of this manipulation on the defendant variable.
• However, correlation between the two variables does not indicate any causal relationship between them. Correlation does not always imply equal causation.
Even though majority of experiments involve study of groups, single-case experimental designs, such as ABAB designs, can also be employed to arrive as causal inferences in individual cases.
Animal research referred to as analogue studies that provide an approximation to the human disorders of interest can also be employed. Generalizability is among the challenges posed by animal research. However, animal research in particular has been very informative in this field of research.