Suppose one’s task is to infer the meaning of the word “thermoluminescence”. The word
is probably unfamiliar to most people. But many people know that the prefix “thermo-”
refers to heat, that the root “luminescence” is a verb meaning to give off light, and that
the suffix “-ence” is often used to form abstract nouns. Moreover, a reasonable
interpretation of a possible relation between “thermo-” and “luminescence” would draw
on one’s knowledge that heat typically results in some degree of light. Note that this cue
derives from an interaction between the prefix and the stem. Neither element in itself
would suggest that the light emitted from heat would be a relevant property for inferring
word meaning. These cues might be combined to infer that “thermoluminescence” refers
to a property of light emission from heated objects. This inference would be correct. These
internal contextual cues represent one possible classification scheme. The extent to which
these cues are utilized, if present, depends on the mediating variables described in the
next section.
Mediating Variables
The mediating variables specify relations between a previously unknown word and the
external context in which it occurs, that mediate the usefulness of internal contextual
cues. The model includes five variables that affect internal cue usefulness, usually by
influencing the effort to be expended on deciphering the word in general, and on utilizing
the internal context in particular. The mediating variables are the same as the ones
previously referred in the section decoding from external context (see p. 42).
To summarize, Stemberg and Powell’s theory of word learning from internal context
specifies kinds of internal cues that individuals can use in inferring meanings of previously
unknown words and also specifies variables that affect how well these cues can be utilized
in actual attempted applications. The contextual cues refer to the types of information that
might be present within the word; however, these cues are not sufficient for describing
actual context utilization. Thus, the theory also includes a set of mediating variables that
determine the differential application of the set of internal contextual cues, both across
texts for a single individual and within a single text across individuals.
64