Self Similarity

One of the problems i have discovered since building the first set of video tutorial maps, is the fact that the maps show a high degree of self similarity.

Essentially self similarity is the property an object exhibits where it shows the same structural features regardless of scale. For example: [fig3].

Self similarity presents a unique problem to my mapping project as it makes the identification of scale difficult for the user. The importance of being able to recognise the zoom level of the image window with respect to the global map is crucial. Firstly it allows the user to locate their relative position within the map, easily find the parent node and associate context to the video or article they are viewing from the "content" node.Secondly self similarity works against the user when they are trying to uniquely identify content node clusters as to quote a user from initial trials "they all look the same from a distance".

Breaking Symmetry
One possible solution to the problem of selfsimilarity to impose symmetry breaking on the positioning of the nodes. This will result in a asymmetric positioning of parent nodes and in turn clusters of content nodes. Of course i have yet to figure out the best way to break symmetry in a controlled manner.

Artificial Scale Markers
Another possibility is to create some sort of artificial scale marker that the user can use to quickly identify the scale of the section of the map in the viewing window. Although their is a clear scale change between parent and child node the effect is only useful form a distance and you need to have a relative reference to see the scale change. when you are zoomed in the map their is no obvious relative reference so an artifical reference such as a scale marker must be made.

An effective scale marker could be to create a symbolic code that appears at the top of a category node. A simple symbolic code could be to use a series of dots to denote the hierarchical level of the parent node. For example:

1st order parent node: one dot, .
2nd order parent node: two dots, ..
3rd order parent node: three dots, ...
and so on.



The dots would be useful they wouldnt require much processing to create (as they are points) and the user could get a quick impression of what zoom level they are at by looking at the nearest parent category node. But the dots themselves do not take up much information space.

Note: The content nodes would not contain any scale symbols as the nearest parent node will remain in the window area while content is being viewed.