California Digital Library
Use 
The site gathers many collections and databases, but it is simple to explore and material retrieval is rather quick and easy to achieve, thanks to the hypertextuality of most pages and to the efficiency of its searching tools.
Searchability 
The search engines dedicated to each site area are mainly multiple keyword-based. Academic research databases combine a textual retrieval tool with broad topic selection
Downloading
Textual documents and multimedia files are available in their original format; statistical data and data queries results are offered as xml tables
Navigational Aids
Detailed explanations about search tools are provided at different levels of the site architecture through FAQs and textual sitemap
User Friendliness
Despite the variety and quantity of available data, site structure is quite homogeneous, resulting intuitive for all users