Open-ended questions do not allow participants to answer within a particular limit, i.e. they can provide any kind of answer. If a proper frame of reference is not given, interpretation may lead to several differential contextual answers. Trained interviewers and screened candidates can be chosen to minimize problems that open-ended questions pose. Open ended questions are useful in cases of exploratory research, opinion seeking, suggestion requesting or when the researcher does not have a full understating of the research project.