The Catalogue uses a sophisticated ranking algorithm that takes into account a number of factors when ranking search results. Factors calculated in the algorithm include:

• Where the seach term occurs (e.g. occurrences of the search term in the title field will rank higher than occurrences of the search term in the author or notes field)
• Proximity of search terms (i.e. results where search terms occur closer together will rank higher)
• Number of occurrences of a search term
• Publication date (all other factors being equal more recently published material will be ranked higher)