Nursing Professional Development Certification (NPD-BC) Practice Exam

Which type of validity assesses whether the independent variable caused a change in the dependent variable?

1. Statistical conclusion validity

2. Construct validity

3. External validity

4. Internal validity

The correct answer is: Internal validity

The type of validity that assesses whether the independent variable caused a change in the dependent variable is internal validity. Internal validity focuses on the extent to which the results of a study can be attributed to the manipulations made by the researcher rather than other confounding factors. It is essential in establishing a cause-and-effect relationship, as it requires controlling for extraneous variables that could influence the outcome. By ensuring that the only factor affecting the dependent variable is the independent variable being tested, researchers can make stronger claims about causation. High internal validity allows for more confidence in the conclusions drawn from the data, asserting that any observed changes in the dependent variable are indeed the result of the independent variable's influence. Other types of validity, while important in different contexts, do not specifically address this cause-and-effect relationship. Statistical conclusion validity relates to the appropriateness of the statistical tests used in the analysis, construct validity evaluates whether the operational definitions of variables accurately reflect the underlying constructs, and external validity concerns the generalizability of findings to other settings or populations. Each plays a unique role in the integrity and applicability of research findings, but internal validity is the one that specifically signifies the causative link between variables.