Another issue researchers must anticipate is maintaining population validity. This means that if inferences are made from the research sample size, they must be also applied to the population. If the group study shows that a balanced breakfast will increase test scores by 25%, then the same inferences can be made to all fourth graders nationwide. Failure to obtain adequate population validity will undermine the credibility of the research project (Action Research. 2002).
As with most research project, this particular data documentation plan is not set in stone. As time progresses and the study continue to develop, one may find that an entire collection plan will need to be recreated and implemented in order to ascertain valid inferences about the research in question.
References
University of Phoenix (Ed.). (2002) Action Research [University of Phoenix Custom
Edition e-text]. Boston, MA: Pearson Custom Publishing.