The measure of the lexical richness of literary texts as a tool in thecomparative analysis of literary style has been hampered by the problem ofthe inequality of text lengths within and between literary corpora. Thispaper proposes an empirical method of description of lexical richness byaveraging measures on multiple chunks of text of a standard lengthwithin a literary work or corpus. A workss average vocabulary richness,average portion of hapax legomenaof the corpus from which it derives,and average repetition of frequently appearing vocabulary may thencharacterize that work relative to other works partitioned along withit. This method reveals the possibility of significant variance of thesemeasures of vocabulary among works of a single authorss corpus and warnsagainst the notion of some absolute authorial stylistic character. Weapply this method of vocabulary averaging to the corpora of threeplaywrights from classical antiquity whose works are chronologicallyrankable: Euripides, Aristophanes, and Terence. We look for trends in vocabulary richness over time, which we posit functions as anindicator of progressively changing authorial ability or inclination. This method then holds the potential of predicting datesfor undateable or tenuously dated works within a corpus of otherwisesecurely dated texts. From the results derived, a relatively late date forthe composition of the redrafted version ofAristophaness Clouds appearslikely; we predict an early composition date for the redraft of TerencessHecyra (and thus are inclined to think that the playwright did verylittle redrafting); and finally we findEuripidess Electra andSupplices exhibiting vocabulary characteristics of extremely latecomposition and we predict dates much later than those assigned based onmetrical considerations.