The Random Indexing approach is motivated by the Johnson-Lindenstrauss Lemma (Johnson and Lindenstrauss, 1984), which states that if we project points into a randomly selected subspace of sufficiently high dimensionality, the distances between the points are approximately preserved.
we conclude that concept-based representations constitute a viable supplement to wordbased ones, and that there are categories in the Reuters-21578 collection that benefit from using concept-based representations.