There are many tools available to a webmaster to analyse website traffic allowing them to monitor the number of visitors, see what pages have been accessed and even the length of time each visitors spends accessing the website.
However, despite the considerable data available what is missing is anything to tell the webmaster what the visitor was thinking. Did they like or dislike the site? Was the layout easy to understand or just plain confusing? Did they find it easy to navigate and maybe the most important thing, did they find the information they wanted?