What is a disadvantage of the Delphi technique that may hinder data collection?

The Delphi technique is a structured method for gathering expert opinions and achieving consensus through multiple rounds of surveys or questionnaires. One notable disadvantage of this method is its time-consuming nature. Each round of feedback can take considerable time for both the collection and analysis of responses. Furthermore, the iterative process of refining questions and seeking clarification or further comments from participants extends the overall timeframe necessary to reach a consensus. This delay can be a significant drawback, particularly in situations where timely data collection is crucial, or where decisions need to be made quickly.

The other options present characteristics that are not applicable to the Delphi technique. It does not require participants to meet in groups, operates effectively with both open-ended and closed-ended questions, and can in fact provide rich qualitative data, which are all essential elements of its systematic approach.