In Chapter Five, the question posed was, "What would I like to be able to conclude when I have finished gathering and analyzing my data?" Relevant to this question, the concept of internal validity of design was introduced and developed to clarify the notion of interpreting relationships among variables. A second major consideration pertinent to this question is how widely applicable a given research finding is. This problem relates to the concept of external validity. External validity, then, concerns generalizing from a relationship observed in one set of data to other potential data sets that might have been observed but were not.