576 Text Comprehension and Discourse Processing
informative (e.g., Barwise & Perry, 1983, for semantics;
Chomsky, 1965, for syntax). However, the opposing tradition
has always delighted in pointing out the gap between theory
and reality, as well as the seemingly boundless irrationality of
language and language use. Although this conflict continues
unabated today, an intermediate position has emerged in
recent years that may yet alter the nature of this debate. Con-
nectionist models of language (Elman et al., 1996; also hy-
brid models like W. Kintsch, 1998) are formal, with all the
advantages that mathematical models provide, but they do
not employ the concept of logical rules. Thus, connectionist
models may be better able to account for the disorderly part
of language while retaining the important advantages of a
mathematical model.
The comprehension processes involved in reading a text
and in listening to spoken discourse are essentially the same
(reading and listening comprehension are also discussed in
this volume in the chapter by Rayner, Pollatsek, & Starr).
Texts and conversations are very different in their properties
and structure, task demands, and contextual constraints, but
the comprehension processes are similar. That is, both make
demands on working memory, both require relevant back-
ground knowledge, and both are constructive processes in
which inferences and construction play a crucial role. We de-
scribe the features that set apart reading comprehension and
comprehension of conversations, but most of what we have
to say in this chapter holds for both.
In this chapter we first discuss the role of memory in text
comprehension, focusing on short-term working memory and
long-term working memory. Then we review studies that are
concerned with what people remember from reading a text,
and how they learn from reading a text. Of particular impor-
tance here is what a reader has to already know in order to be
able to acquire new knowledge from a text, and the role of
constructive processes in comprehension and learning. We
then turn to a consideration of current models of compre-
hension and knowledge representations. Finally, we discuss
experiments investigating the factors that influence com-
prehension, making comprehension easier or making it more
difficult.
MEMORY AND TEXT COMPREHENSION
Working Memory
Text comprehension is a task that requires processing and
integration of a sequential series of symbols; as such, mem-
ory processes—especially working memory, due to its stor-
age and computational abilities—are strongly implicated in
comprehension ability (Carpenter, Miyake, & Just, 1994;
Just & Carpenter, 1987; also see the chapter in this volume by
Nairne). Unlike early characterizations of working memory
as a storage system used to hold a few chunks of information,
working memory has come to be seen as a limited resource
for which processing and storage demands compete. Working
memory can be seen as a sort of attentional work space that
keeps information active for short-term use while it directs
cognitive resources for task performance.
It is easy to see how the demands required by text com-
prehension should draw heavily on working memory re-
sources. At the same time text is decoded and processed,
important ideas or current propositions must be maintained in
memory and retrieved at key points in the comprehension
process. Maintaining ideas or propositions from a text at the
same time new text is analyzed is necessary to form infer-
ences, develop an understanding of text coherence, recognize
inconsistencies, and so on. Accordingly, researchers have
come to regard working memory as a key component of com-
prehension processes and the possible source of individual
differences in comprehension.
Daneman and Carpenter (1980; 1983) theorized that indi-
vidual differences in working memory capacity could explain
individual differences in reading comprehension. They ar-
gued that reading processes of poor readers make heavy
demands on working memory that result in a trade-off com-
promising the working memory capacity for maintaining text
information. As a result, poor readers are unable to make the
appropriate connections between text necessary to recog-
nize inconsistencies and, presumably, to link text and form
inferences necessary for expert comprehension. To measure
the functional capacity of working memory for reading,
Daneman and Carpenter developed a measure called the
reading-span test. This test requires readers to read aloud a
series of unrelated sentences at the same time that they mem-
orize the final word in each sentence. Sentences are presented
in sets containing varied numbers of sentences, and the
largest number of sentences for which a participant can recall
all memorized final words in at least 60% of the sets of that
size is defined as the reading span. Reading span differs
among individuals—from about 2 to 5.5 for college students
(Just & Carpenter, 1992)—but can also be influenced by text
complexity or other demanding types of text processing (e.g.,
linguistic ambiguity or text distance).
When reading span is consistently tested, empirical evi-
dence demonstrates that working memory capacity is a reli-
able predictor of proficiency in text processing. Daneman and
Carpenter (1980, 1983) have linked reading spans to various
tests of reading comprehension (including the verbal SAT)
and have demonstrated that reading span can reliably predict