In search of the critical lexical mass: How 'general' is the GSL? How 'academic' is the AWL? by Steve Neufeld & Ali Billuroğlu December 2005 ABSTRACT The concept of vocabulary profiling texts as an aid to teaching and learning English is becoming more widespread due to the availability of computer-based tools. Two commonly used tools are RANGE, a PC-based vocabulary profiler for corpora developed under the auspices of Paul Nation, and the Compleat Lexical Tutor, a web-based suite of lexical analysis tools and resources developed by Tom Cobb, which includes a vocabulary profiler for individual texts. These two popular tools, which are free for anyone to use, rely on two main word lists in common use today: the General Service List (GSL) and the Academic Word List (AWL). Used in conjunction with each other, these two lists comprise between 85% and 90% of the actual words (tokens) in any academic text. However, close examination of vocabulary profiles created using three bands defined by splitting the GSL into the first thousand (K1) and the second thousand (K2) commonly used words, and adding on the AWL words as the third, shows that this breakdown does not yield a vocabulary profile that reflects a natural distribution of words based on common use. This article puts forward an argument that neither the GSL nor the AWL is genre-specific. Rather, their combined word members, redistributed to reflect the natural frequency of distribution of commonly used words, provide a vocabulary profile of a broad range of genres of written texts. It also reports additional research on the identification of contemporary words in common use, leading to the creation of a critical lexical mass of 2,716 word families that consistently provides 90% to 95% coverage of the tokens (not including proper nouns, acronyms or abbreviations) in academic corpora.