Internet surveys can utilize various types of design features to increase interaction with respondents. Very little research has been done on the effects of the interactivity of the web on the quality of responses. This paper examines how interactive features of internet surveys can help reduce item non response in open-ended questions and improve the quality of responses to these questions. This research builds upon two previous studies among US students, that have shown motivational statements (Smyth et al., forthcoming) and interactive follow-up probes (Holland and Christian, 2007) can improve the quality of responses to open-ended questions. In this study the main question to be answered is: Can motivational statements and interactive probing help to improve the quality of the responses of the general population of the Dutch people to open-ended questions and increase the number of respondents that provide an answer?

In this study the effects of motivational statements and follow-up probes on responses to four open-ended questions are explored. The questionnaire used for this experiment included four open-ended questions and several closed-ended questions about the current situation in Dutch society. The survey was conducted in the Dutch CentERdata LISS panel. This LISS panel consists of about 5,000 households; the reference population for the LISS panel is the Dutch speaking population permanently residing in the Netherlands.

Including a motivational statement with the initial question or asking a follow-up probe slightly improved response rates and response quality to open-ended questions in a web survey. Including a motivational statement with the open-ended question significantly improved response rates for only one question but its inclusion increased the average number of words in all four questions. Not very many respondents provided a response to the follow-up probe. However, respondents who were probed provided significantly longer answers than those who were not probed for three of the four questions. The mean number of words was higher when a motivational statement was included with the follow-up probe than with the initial question screen.