methodologie and response effects in web surveys.

In the last few years the internet has become an increasingly popular medium to distribute questionnaires. This method has some very important advantages over paper and pencil surveys. Unfortunately one should recognize that is has some inevitable disadvantages too. One of these disadvantages is the susceptibility for partial or complete non response. Timing is very important on the internet, much more than when using traditional media. E-mail, one of the preferred methods for inviting respondents to participate in a survey, is being threatened by spam and phishing: people are flooded witj virtual mail and become very suspicious, even towards trustworthy wources (such as universities or other writers of surveys). This results in a threat for this novel data collection method.
In this study a series of experiments will be conducted to get a better insight into why people choose to participate in a web survey. Based on some recent studies, we will first conduct some research in the online field. On the one hand the necessary attention will be given to non response, on the other hand we will study response and context effects. The main focus will be on the influance of response scales on these effects. The results of this research could help us to optimize web surveys and thus to obtain better overall data quality.