Situational enhancement of design validity: The case of training evaluation at the World Bank Institute

The critical role played by research design has been widely discussed among evaluators. Generally there is a consensus that experimental and certain q uasi-experimental designs are preferable for their ability to eliminate or minimize threats to internal validity. Least preferred are the class of non experimental designs, particularly the one-group, pretest-posttest design. This design, while convenient, is regarded as incapable of controlling for most standard threats to internal validity. In practical applications, howe ver, this design may be stronger than expected. The context, or situation, in which the design is applied may make one or more standard threats to val idity implausible. An example From evaluations at the World Bank institute is provided to demonstrate the effectiveness of this design within a given situation. It is suggested that evaluators carefully review the plausibilit y of each threat to design validity within the context to which it is appli ed as a means of adding to their repertoire of existing evaluation tools.