578 Text Comprehension and Discourse Processing
involved in text comprehension could exceed the capacity of
short-term working memory—but they are all required for
the process of comprehension, and are demonstrably used in
that process. How can these facts about memory demands in
comprehension be reconciled with the strong laboratory evi-
dence for a strictly limited working memory capacity of three
or four chunks?
Psychologists have sometimes despaired in the face of this
puzzle, asserting that real-life memory is totally different
from memory studied in the laboratory. Laboratory results
have been claimed to be unnatural, irrelevant, and hence use-
less (Jenkins, 1974). Recalling information read in the daily
paper at breakfast or retelling the complicated plot of a novel
is quite easy; however, it takes an hour of hard work to mem-
orize a list of 100 random words in the laboratory! An indi-
vidual cannot repeat more than about nine digits on a digit
span test, but the experienced physician keeps in mind seem-
ingly endless chunks of patient information, laboratory data,
relevant disease knowledge, alternative diagnoses, and so on.
Such information can be shown to influence the physician’s
reasoning and decision processes—but how could it fit into
the limited capacity working memory we have identified in
laboratory research?
Ericsson and Kintsch (1995) have provided an answer to
these questions, and were able to successfully reconcile
everyday memory phenomena with the results of laboratory
studies of memory since the days of Ebbinghaus. Their argu-
ment is based on a distinction between short-term working
memory and long-term working memory. Short-term work-
ing memory is what has typically been studied in the labora-
tory; it plays an important role in discourse comprehension,
as discussed in the previous section. Long-term working
memory (LTWM) is different: It is not capacity limited, but it
only functions under certain rather restrictive conditions.
Nevertheless, these are the conditions under which we ob-
serve prodigious feats of memory in real life.
Long-term working memory (see also W. Kintsch, 1998;
W. Kintsch, Patel, & Ericsson, 1999; LTWM is also
discussed in this volume in the chapter by Leighton &
Sternberg) is a skill experts acquire. In fact, becoming an ex-
pert in any cognitive task involves the acquisition of LTWM
skills. The skill consists in the ability to access information in
long-term memory via cues in short-term working memory
without time-consuming and resource-demanding retrieval
operations. Experts can access relevant information in their
long-term memory quickly (in about 400 ms) and effort-
lessly. This accessible portion of their long-term memory be-
comes part of their working memory—their LTWM. How
much information can be accessed depends on the nature and
efficiency of the retrieval structures experts have formed, but
there are no capacity limitations. Thus, experts retrieve task
relevant knowledge and experiences quickly and without
effort, and recall what they did with ease. Examples of such
expert memory are the physician making a medical diagno-
sis, the chess master playing blindfold chess (for further dis-
cussion on development of expertise, see the chapter in this
volume on Procedural Memory and Skill Acquisition by
Johnson)—and all of us when we use our expertise in reading
familiar materials, such as a story or the typical newspaper
article.
Long-term working memory cannot be used in traditional
laboratory experiments. Ebbinghaus wanted to study what he
saw as pure memory unaffected by our daily experience;
hence he invented the nonsense syllable. And although mod-
ern psychologists no longer use the nonsense syllable, they
have followed Ebbinghaus’s lead in excluding or controlling
the role of experience in their experiments as carefully as is
possible. The types of tasks used in traditional laboratory ex-
periments thus remove the essential component of LTWM—
experience. When it comes to repeating a string of digits or
memorizing a list of words, we are all novices, and we cannot
use whatever LTWM skills we might possess. However,
when we read an article or participate in a conversation on a
familiar topic, a lifetime of experiences and a rich store of
knowledge become relevant. We comprehend as experts and
remember as experts. Of course, our expertise is limited to
certain familiar, frequently experienced topics, or to some
restricted professional domain. If we read or listen outside
our domain of expertise, we immediately become aware of
our inability to comprehend what we read because we cannot
activate the required background knowledge. In unfamiliar
domains, our recall is equally limited because we do not
have the knowledge that would allow the proficient and easy
recall that occurs with familiar texts. Unfamiliar domains
restrict the use of experience just as in the laboratory, where
the experimenters carefully design their experiments in such
a way to prevent us from using whatever knowledge we
might have.
For the remainder of this section, assume someone is read-
ing a simple text in a familiar domain—a straightforward
story, for example. Alternatively, one could assume that
someone is listening to a story, for example a soap opera.
Although soap opera stories are rarely straightforward, they
(like most stories we encounter) are about human affairs
(no pun intended), motivations, actions, character—things
we have experienced throughout our lives. We are familiar
with these concepts in the form of texts, but primarily we un-
derstand them through our actions and interactions in the so-
cial world. Thus, we are highly familiar with most stories in
general, with the words and syntax used in the story, and with