Generation of a filter that separates elements to be displayed from elements constituting data

A technique to improve the efficiency for generating a filter for separating elements to be displayed from elements constituting data. At a client, a content acquisition unit acquires content from a server. A content division unit divides the content into elements. An element display unit randomly displays the elements at positions different from positions at which the elements of the content in an original form are displayed. A selected-element identification unit identifies an element selected by a user from the elements. A filter generation unit generates a filter based on the identified element and saves the filter in a filter saving unit. A filtering unit applies the filter saved in the filter saving unit to the content. A content display unit displays the filtered content.