Evaluative Meanings and Disciplinary Values - eTheses Repository ...

as chi-squared or (more commonly) log-likelihood. If this algorithm finds that a word occurs
significantly more frequently in the research corpus than it occurs in the reference corpus, this
which forms the final output of the process. The researcher then performs other kinds of
analysis (usually concordance analysis) on these words in order to make claims of a more
qualitative and interpretative nature about the corpus and about the discourse community,
genre or text type that the corpus has been compiled to represent.
The other approach to quantitative discourse analysis that has gained a particularly
high profile in recent years is multidimensional analysis (MDA). This approach was first
popularized by Biber (1988, 1993a, 1993c) as a means of discovering the different linguistic
characteristics of spoken and written genres (also sometimes called register variation in his
work) in English. In Bibers work, MDA follows three main stages. In the first, the analyst
draws up a (usually very long) list of language features for analysis. These usually include
both grammatical features such as tense and aspect markers, pronouns, question forms and
subordinating features (e.g. that- clauses and wh- clauses), and more lexical features such as
adj
among these features are discovered using the statistical procedure known as factor analysis.
The constellations of co-varying features identified by the computer are thus unsurprisingly
known as factors. The advantage of using factor analysis at this stage is that it can identify
negative as well as positive co-occurrence patterns in corpus data. That is, it can detect not
only which features tend to appear together but also which features tend to disappear together
in different text types. Finally, each factor is redesignated as a dimension, which means that it
is interpreted qualitativel
, 1988, p. 64). For example, the second of the
seven factors identified by Biber (1988) includes positive co-occurrence scores for past tense
verbs and third person pronouns, and negative co-occurrence scores for present tense verbs
and attributive adjectives. Biber (1988, p. 109) interprets this set of covariances as
s it as
Dimension 2: narrative versus non-narrative concerns. The advantage of establishing
dimensions such as this is that individual text types and genres can be placed on a cline. In
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