Identifying the Core Vocabulary for Adults With Complex Communication Needs From the British National Corpus by Analyzing Grouped Frequency Distributions

Abstract

Purpose: This study is aimed to identify the high-frequency vocabulary (HFV), otherwise termed "core vocabulary" for adults with complex communication needs. Method: Three major characteristics of the HFV-a relatively small number of different words (NDW), a relatively high word frequency, and a high word commonality across speakerswere examined so as not to lose any candidate words for the HFV. Specifically, instead of applying the traditionally used cutoff word frequency of 0.5 parts per thousand, a grouped frequency distribution was used to examine the appropriate frequency ranges to determine the HFV candidates. To improve the representativeness of the HFV across ages, social backgrounds, conversation situations, and topics, 330,000 spoken words of 66 adults (29 men and 37 women; M-age = 45.47 years, SD = 16.07) were extracted from the British National Corpus database for analysis. Results: A distinct pattern of NDW was observed from the frequency of 0.1 parts per thousand in the grouped frequency distribution. In total, 671 words were found to be candidates for the HFV, accounting for 90.94% of the total sample words. After the word commonality analysis indicated at least 80% commonality across speakers, 203 words were selected for the final HFV; accountability was calculated at 80.62%. Conclusions: With the innovative word analysis approach, this study provided an HFV list that can be used for a wide range of conversation topics. This method provides a scientific and principled approach to identifying and organizing vocabulary for augmentative and alternative communication (AAC) intervention that does not exist in many AAC resources that promote "core vocabulary" with identifying the source for vocabulary selection.