Dapper, Semantify the Web Sites

For sure, Dapper can help our web sites convey semantic information or meta data and make our web sites more structured. But I doubt whether it can help the search engine improve the accuracy or precision of the results of a keyword search. Have a look at the keyword search over relational database or XML database. The data is structured, but the results of a keyword search is not ideal. Therefore, the precision of results is not determined by whether a web site is semantified. Semantifying is just the first step.
Users express their intention through several keywords, but these keywords convey too limited semantics, so it is very difficult to find out what information is really wanted by the users. If this problem can not be properly solved, the semantic information conveyed by the web sites may be not very helpful. Therefore, when our web sites become semantified, we also need a new simple query pattern to make the keywords more semantic.