29. A website building system, the system comprising: a memory; a processor; a database to store at least one layout and an associated signature wherein said signature represents the semantic composition of said at least one layout based on at least one of: a user supplied and a system generated handled component set; a page analyzer to receive a layout of said website building system, said layout based on a set of components, said components having types as defined by said website building system and to analyze at least said types and to generate an associated signature for said website building system layout wherein said associated signature for said website building system layout represents at least a semantic composition of said components of said website building system layout; a signature comparer to match an associated signature of a layout of said website building system to an associated signature of said at least one layout stored in said database and to retrieve multiple alternate layouts for said website building system layout from said database, wherein said alternate layouts are visually different and semantically similar to said handled component set; an experiment creator to receive said alternate layouts and to present them to a user as part of a controlled experiment; an experiment analyzer to analyze results of said selection of said layout by said user to provide statistical information on preferred layouts for said website building system; and wherein said processor activates said a page analyzer, said signature comparer, said experiment creator and said experiment analyzer.
29. A website building system, the system comprising: a memory; a processor; a database to store at least one layout and an associated signature wherein said signature represents the semantic composition of said at least one layout based on at least one of: a user supplied and a system generated handled component set; a page analyzer to receive a layout of said website building system, said layout based on a set of components, said components having types as defined by said website building system and to analyze at least said types and to generate an associated signature for said website building system layout wherein said associated signature for said website building system layout represents at least a semantic composition of said components of said website building system layout; a signature comparer to match an associated signature of a layout of said website building system to an associated signature of said at least one layout stored in said database and to retrieve multiple alternate layouts for said website building system layout from said database, wherein said alternate layouts are visually different and semantically similar to said handled component set; an experiment creator to receive said alternate layouts and to present them to a user as part of a controlled experiment; an experiment analyzer to analyze results of said selection of said layout by said user to provide statistical information on preferred layouts for said website building system; and wherein said processor activates said a page analyzer, said signature comparer, said experiment creator and said experiment analyzer. 30. The system according to claim 29 and wherein said controlled experiment is based on at least one of: a visual quality of said layout, an explicit user metric, an implicit user metric and a system use metric.