Ranking is based on:
- Size = Total number of web pages (by Google), excluding the rich files (10%).
- Visibility = The visibility is obtained from combining external inlinks and referred domains according to Majestic SEO (50%).
- Rich Files = The sum of the following file types(by Google): pdf, doc+docx, ppt+ppts and ps+eps (10%).
- Scholar = The combination of the total number of papers in Google Scholar and the recent values for the 5-year period 2007-2011 (30%).