1. A method of mapping hyperlinks between a plurality of data files comprising: a step of, for a first file, in a display area displaying a first region and one or more second regions, said second regions respectively representing one or more second files which are accessible from the i-th file by a hyperlink, and being spatially related to the first region, the sizes of said second regions being according to a first distance scale; and (n−1) further steps, i=2,. .. , n, of, for each i-th file, displaying one or more (i+1)-th regions, said (i+1)-th regions respectively representing one or more (i+1)-th files which are accessible from the i-th file by a hyperlink to the (i+1)-th file, and being spatially related to the i-th region representing that i-th file, the sizes of said (i+1)-th regions being according to an i-th distance scale smaller than the (i−1)-th distance scale.