1. A method for classifying a biological specimen, the method comprising: (A) determining whether a model precondition included within a selected model in a plurality of models for classifying a biological specimen into a biological sample class has been satisfied; each model in said plurality of models comprising a plurality of calculations, a calculation algorithm, and an aggregation algorithm, and optionally comprising one or more preconditions; wherein each calculation in each said plurality of calculations specifies an identity of one or more cellular constituents in said biological specimen to be used in a calculation algorithm, and when the model precondition for the selected model has not been satisfied, the selected model is not used; and when the model precondition for the selected model has been satisfied, the determining further comprises testing the selected model by: (i) choosing a calculation from the plurality of calculations in the selected model; (ii) obtaining a cellular constituent abundance value for each of said one or more cellular constituents specified by said calculation from said biological specimen; (iii) computing the calculation using the cellular constituent abundance values obtained from the biological specimen in accordance with the calculation algorithm of the selected model; (iv) repeating steps (i) through (iii) for one or more other calculations in the selected model; and (v) aggregating each calculation computed in step (iii) for the selected model in accordance with the aggregation algorithm in the selected model; and (B) repeating step (A) with at least one other model in the plurality of models.