6. The method according to claim 1 , further comprising: generating group layout information for inclusion in layout information used to identify one or more elements of the element group to be rendered for display in the display area.
6. The method according to claim 1 , further comprising: generating group layout information for inclusion in layout information used to identify one or more elements of the element group to be rendered for display in the display area. 11. The method according to claim 6 , further comprising: storing the group layout information; processing the stored group layout information to identify one or more elements of the element group to be rendered for display in the display area when the selected portion of the layout area of the data set covers a first part of the layout area of the data set; and re-processing the stored group layout information, to identify one or more elements to be rendered for display in the display area when the selected portion of the layout area of the data set covers a second, different part of the layout area of the data set.