Which of the following is an advantage of a panel?

Panel members may be influenced by outside sources.
Panel members may leave for various reasons.
Replacement members may not reflect the same demographic.
Reasons for changes in trends can be identified.

Reasons for changes in trends can be identified.

The advantage of a panel is that reasons for changes in trends can be identified.

The advantage of a panel is that reasons for changes in trends can be identified. To determine the advantage of a panel, you can evaluate each option individually:

1. "Panel members may be influenced by outside sources": This statement suggests that panel members can potentially be influenced by external factors, which is not necessarily an advantage. Thus, this option is not the correct choice.

2. "Panel members may leave for various reasons": This statement highlights the possibility of panel members leaving the panel, which may introduce instability and disrupt the continuity of data collection. Therefore, this option is not the correct answer.

3. "Replacement members may not reflect the same demographic": This statement implies that if panel members are replaced, the demographic representation of the panel may not stay consistent. This inconsistency may introduce biases and hinder the accuracy of the data collected. Hence, this option is also not the correct answer.

4. "Reasons for changes in trends can be identified": This statement suggests that one advantage of having a panel is the ability to identify the reasons behind changes in trends. By observing the behavior and opinions of the panel members over time, researchers can analyze the collected data to determine the factors that contributed to various trends. This allows for a deeper understanding of the underlying causes of changes. Therefore, this option is the correct answer.

In summary, the correct answer is that the advantage of a panel is that reasons for changes in trends can be identified.