An update
Although the website was not widely advertised we are very happy with the interest. In August 2009 already more then 700 people completed the questionnaire at least once. Of those people 50% completed the questionnaire already twice or more. This is important, because completing the questionnaire repeatedly over time allows us to analyze possible changes over time. We want to know whether sleep patterns change over the season, do people wake up later during the winter, do they sleep longer? Are there individual differences, and if so can we find an explanation for these differences. So also if you do not experience changes please go in, we need that information too.
For these reasons it is very important that you keep on sending us your sleeping habits over the year. Please go in with the questionnaire, at least one year. We count on you! Thank you very much.