Coverage-based Frequency Bands: A Proposal

Second language vocabulary research makes much use of word frequency lists and their division into bands. In recent years, bands of 1,000 items have become conventional. However, there does not seem to be any firm basis or rationale for this. Conventional banding may be questioned since the utility of words varies greatly depending on frequency, because there are enormous differences in frequency within higher bands, and because the reliability of the placement of words in bands becomes progressively poorer at lower frequency levels. This article suggests an alternative approach: basing bands on coverage levels. Because of the frequency distribution of words, this means the highest frequency bands would contain very few words, while lower frequency bands would contain a great many words. The article shows how such bands can be constructed and presents a re-analysis of the results of a vocabulary test designed with conventional bands in terms of coverage-based bands. This re-analysis produces a very different profile of learners’ knowledge, and it is argued that the shape of this profile may be more useful in terms of guiding instruction in that it gives a clearer indication of which words should be targeted for a group of learners. It is further argued that the smaller number of words contained in coverage-based bands at higher frequency levels makes them a more feasible basis for instruction. The article thus concludes that coverage-based bands may be a fruitful avenue for researchers to explore.