Adaptive search engine

An adaptive search engine ( 1 ) having a plurality of data items ( 4 ) from one or more data sources ( 5 ) stored in at least one database searchable by a search query ( 6 ) of a least one keyword ( 7 ) to produce a corresponding ranked search result listing ( 8 ) of data items ( 4 ), said search engine having a plurality of selectable filters ( 9 ) applicable by the search engine and/or the user to filter at least a portion ( 10 ) of the data items ( 4 ) of the search result listing ( 8 ), characterised in that said search engine records an association between a filter ( 9 ) applied to a search query ( 6 ) and a data item ( 4 ) selected by a user from said filtered portion ( 10 ) of the corresponding search result listing ( 8 ), wherein each recorded association contributes to the weighting given by the search engine ( 1 ) to application of said filter ( 9 ) in a subsequent search for at least one keyword ( 7 ) of said search query ( 6 ).