The 1.1 API help text for search says that the pagesize parameter can go up to 100. Indeed, passing a value up to 100 returns a result, while passing pagesize yields an HTTP 400 status (Bad Request). However, only up to 30 results are actually returned per page even if pagesize=100 (e.g. http://api.stackoverflow.com/1.1/search?tagged=c&pagesize=100).