Determining and validating fringe vocabulary categories and items appropriate for children who require AAC from a Sepedi language background

Abstract

Purpose and aim:  While AAC tool developers often use the core vocabulary approach as a starting point when selecting and providing access to vocabulary, various authors have cautioned against the exclusive provision of core vocabulary to children requiring AAC. Access to fringe vocabulary, in combination with core, allows children in need of AAC to compose more complex sentences and communicate about their own contexts and life.

Various pre-designed electronic and non-electronic core-fringe-based AAC tools are available, specifically in European languages.  While fringe vocabulary is typically customized to the individual, preselected fringe provides a helpful starting point in the form of various words and categories that can then be customized.

South Africa consists of a linguistically and culturally diverse population.  However, at present, no pre-designed core-fringe based AAC tools exist for any of the African languages spoken in the country.  A Sepedi core board was co-developed with stakeholders to bridge this gap.  However, pre-selected fringe vocabulary has not been included to this AAC tool. This study aimed to identify and validate fringe vocabulary categories as well as exemplar fringe vocabulary items for children aged 4-12 years requiring AAC from a Sepedi language background to inform the design of a core-fringe Sepedi AAC tool by (a) determining  fringe vocabulary categories as well as possible fringe vocabulary words from word frequency lists derived from transcripts of speech samples of Sepedi-speaking Grade R learners and (b) validating the appropriateness of the fringe words and categories for children aged 4-12 years by obtaining the perspectives of Sepedi-speaking speech-language therapists (SLTs).

Method: A descriptive multi-method design was used to address the two sub-aims. To develop the list of fringe vocabulary categories and exemplary items, secondary data analysis was used. Both qualitative and quantitative analyses of de-identified Sepedi transcripts and word lists generated by Moswathupa (2024) and Mothapo (2019) from six Grade R learners from Lebowakgomo (Capricorn district municipality) and six Grade R learners from Sekhukhune in Limpopo (South Africa) were undertaken to identify the possible fringe vocabulary categories and items.

The unique words from each set of transcripts were combined into one consolidated word list with combined frequency counts. These words were then classified into 20 semantic-syntactic categories using a combination of in- and deductive categorization. To validate the determined fringe vocabulary categories and items, eight Sepedi speaking SLTs were recruited through non-probability sampling techniques. The SLTs validated the fringe vocabulary categories and items through a predominantly quantitative online survey, providing ratings using a 4-point Likert scale.

Results: Twenty fringe vocabulary categories and 353 possible vocabulary items were determined from the secondary data analysis. Regarding the validation, results indicate that Sepedi-speaking SLTs rated most categories included in the survey to be either quite (3) or very important (4). The average importance rating for the categories was 3.5 (1 = not at all important; 4 = very important). Overall, the category of ‘home’ received the highest overall importance rating (M = 3.88), while the categories ‘abstract words’ and ‘celebrations’ received the lowest overall importance rating (M = 3.13).

Regarding the vocabulary items, an average rating of 3.4 was received across all words. Average ratings per word ranged from 2.13 for the code switch ‘social’ to 13 words receiving an average rating of 4.0. Interestingly, four came from the category ‘animals and nature’ and consisted of the Sepedi words for ‘wind’, ‘tree/plant’, ‘dog’, and ‘cow’.

SLTs also suggested additional vocabulary items for various categories, notably for the categories ‘animals and nature’ (10 additional words), ‘action words’ (9 additional words) and ‘people’ (also 9 additional words).

Conclusions: While fringe vocabulary is deemed personal and specific to an individual, SLTs found the suggested fringe vocabulary items and categories important to include on a Sepedi core-fringe-based AAC system. The study thus suggests that the provision of a framework in the form of predetermined categories and items can be a starting point to assist SLTs in selecting appropriate vocabulary when customizing AAC tools for children who require AAC from a Sepedi language background.