Which of the following is a practical issue with questionnaires?

The correct answer highlights a significant practical challenge associated with using questionnaires, particularly when they are distributed by mail. A slow response rate can impede the research process, leading to delays in obtaining the necessary data for analysis. This issue may stem from various factors, including the potential respondents' lack of interest, forgetfulness, or other competing priorities that can deter them from responding promptly. When researchers send out questionnaires and encounter low response rates, they may need to invest additional time and resources into follow-ups or reminders to encourage participation. This can hinder the timeline of a study and may also introduce issues regarding the representativeness of the sample if responses from certain demographics are slower to arrive.

In contrast, the other options either do not universally apply to questionnaires or represent different considerations that, while important, do not capture a foundational concern regarding practical implementation. For instance, the expense related to questionnaires can vary widely depending on the method of distribution and the resources available, making it not inherently true that they are always expensive. Similarly, while analyzing data from questionnaires can indeed take time, this is more related to the complexity of the data rather than a practical issue inherent to the format itself. Also, questionnaires do not inherently require a small sample size; they can be effective with large