The contextual network graph does not encode any information about grammatical or hierarchical relationships between terms.  Its structure is determined purely by term co-occurrence across the collection.

Each edge in the graph has a strength assigned to it whose magnitude depends on our choice of the local and global term weighting scheme used in generating the TDM.  The only constraint on weighting schemes is that all edge weights must fall in the interval (0,1).

From:

M. Ceglowski, A. Coburn, and J. Cuadrado. Semantic search of unstructured data using contextual network graphs. Preliminary white paper, National Institute for Technology and Liberal Education, Middlebury College, Middlebury, Vermont, 05753 USA, 2003.

Tags: Latent Semantic Analysis