Then, when a segment containing the prime in less than minimal combination is presented for identification, its location in cue space lies within a restricted number of units of within-cluster variance of the central location of the prime cluster. The number of such distance units determines headedness in the segment, with separate thresholds for occurrence as head and as operator. In § 3 we describe in more detail the stagewise procedure for identifying via quadratic discriminants the primes present in segments. .
