1. A method for selecting sufficient dominant features for representing a collection of data, said method comprising the steps of: (a) computing a linear model using training data selected from among said collection of data, said linear model defining a plurality of characteristic features; (b) selecting a sub-set of potential dominant features from among the plurality of characteristic features; (c) determining a measure of the accuracy with which the current sub-set of potential dominant features accurately represent said collection of data; and (d) in response to said measure of accuracy not meeting a predefined first threshold, defining a new sub-set of potential dominant features from among the plurality of characteristic features, wherein said new sub-set is bigger than, and replaces, the immediately previous sub-set of potential dominant features, and returning to step (c); (e) defining the current sub-set of potential dominant features as said sufficient dominant features for representing said collection of data.