Independent Variables, Fidelity, and Social Validity

Single case design (SCD) research allows for assessment of causal relations between one or more researcher-manipulated independent variables and one or more dependent variables. Identifying causal relations in SCD studies includes careful planning and implementation of data collection and implementation. Procedural fidelity is the degree to which procedures of all experimental conditions are implemented as intended. Measurement of procedural fidelity has been suggested as a necessary component of SCD research to identify implementation errors made by researchers for both formative and summative purposes. Formative analysis of procedural fidelity can be used to evaluate ongoing needs and identify when to provide additional training to the implementer. Summative analysis of procedural fidelity increases internal validity of the study and can be used to describe variability in the dependent variable. Summative analysis allows researcher to document that the intervention was implemented as planned and precisely describe conditions under which it was effective.