Relevance & Research Question: The lack of interviewer assistance increases response burden in Web surveys and enlarges the risk that respondents misinterpret survey questions. Clarification features and instructions are seen as an effective means of improving question understanding and response behavior. However, clarification features often suffer from limited attention. Thus, they need to be positioned exactly where they are needed (Dillman, 2000). In the past it has been suggested to place clarification features after the question text. By contrast, recent findings from an eye-tracking study indicated that clarification features concerning question meaning are particularly noticed when they are presented before the question text whereas formatting instructions should be placed after the response options (Kunz & Fuchs, 2012). This study aims to answer the question whether optimal positioning of clarification features depends on the cognitive stage addressed by the instructions.

Methods & Data: In four randomized field experimental Web surveys a between-subjects design was implemented to test the effectiveness of three different positions of clarification features related to open frequency and open narrative questions: after the question text, before the question text and after the response options. Clarification features concerning question meaning, the retrieval of a response and the formatting of the response have been tested.

Results: Results indicate that clarification features regardless of the processing stage of the question-answer process addressed are best positioned after the question or after the response options. Instructions placed before the question stem yielded the smallest effect.

Added Value: The use of clarification features in Web surveys has a positive effect on survey responses and helps improve data quality. The optimal position of instructions does not depend on the cognitive stage of the question-answer process addressed. Survey researchers should avoid placing clarification features before the question since this position seems to be least efficient. However, results also indicate that clarification features positioned after the input field are similar effective as compared to clarification features positioned after the question stem.