26. The method of claim 25 , wherein the generating of a score for a structure having an aggregate comprises calculating (a) a deviation score of the search expression, and (b) for each sub-expression of the search expression, a density and a relevance center of the sub-expression, for the aggregate, the calculating being performed using at least relevance geometry of the aggregate, one or more deviation scores of the search expression of each child of the aggregate, and a density of each sub-expression of the search expression for each child of the aggregate.
26. The method of claim 25 , wherein the generating of a score for a structure having an aggregate comprises calculating (a) a deviation score of the search expression, and (b) for each sub-expression of the search expression, a density and a relevance center of the sub-expression, for the aggregate, the calculating being performed using at least relevance geometry of the aggregate, one or more deviation scores of the search expression of each child of the aggregate, and a density of each sub-expression of the search expression for each child of the aggregate. 28. The method of claim 26 , further comprising assigning relevance geometry to the aggregate, including assigning relative sizes to children of the aggregate, assigning relative distances between children of the aggregate or correlating distances within children of the aggregate with distances between children of the aggregate.