Employing the methodology of multi-dimensional (MD) analysis devised by Biber (1988), this study identifies and examines 6 major dimensions of variation in Dagbani, a Gur language of Northern Ghana. Components of this research include a focus on unique oral traditions and the collection of a balanced corpus of comparable written and spoken texts. Factor analysis is used to identify sets of co-occurring linguistic features that are characteristic of different dimensions of variation, and various genres are ranked against one another based on the composite frequency of these features. Excerpts are presented to exemplify and explicate the functional categories underlying the dimensions and to illustrate how the genre of which the text is representative is associated with the relevant dimension of variation. The results of this research demonstrate that variation formerly attributed to medium of communication (speech versus writing) is better explained by a complex interplay of register categories. The findings largely corroborate earlier MD studies in other languages that find no dimension of variation that categorically distinguishes written texts from spoken ones.

Texts from Dagomba oral traditions prove to be especially helpful in disambiguating the contextual factors of degree of planning and medium of communication. First, oral history chanted by the luηa drummers and traditional fable-telling (salima) are among the few spoken genres that pattern like the predominantly written texts on the planned vs. unplanned dimension. Secondly, one dimension of variation identified in this study distinguishes oral history from all other texts, and the features of this dimension are subsequently examined in a more focused comparison between oral history and its written counterpart.