Further, stakeholders, and members of the general public tend to remember and be moved by case illustrations that describe an individual's experience. On the other hand, data that are entirely qualitative can quickly become unwieldy. Processing this information is very labor intensive and may be well beyond the resources available. Quantitative data summarize information from large numbers of people in a concise way. Furthermore, the greater the methodological rigor, the greater the certainty that it is the program, and not some other factor, that accounts for the differences identified in family functioning.
Rigor can be much more easily determined with quantitative methods.
Although a distinction has been drawn between these two methodological types, in the real world, these lines are often blurry. For example, in Section 6, an overview of survey research is presented. Further, questionnaires quite often contain both types of questions. Below, three qualitative techniques are described that are easy to use and valuable at all stages of program evaluation. The interviewer can clarify questions, and avoid a problem such as illiteracy or language barrier.