584 Text Comprehension and Discourse Processing
Although active processing is a powerful determinant of
text learning, it is important to remember that increasing the
difficulty of text is fruitful only for the reader with adequate
knowledge. Further, increasing text difficulty often is prob-
lematic and time consuming. This may explain the large
number of instructional programs that have been designed to
teach active strategies for comprehension. The effectiveness
of such strategies is unclear; some research shows clear ben-
efits after teaching strategies and some does not. For exam-
ple, Palincsar and Brown (1984) found that training children
on general comprehension processes results in strong and
generalizable improvements in text understanding. Yet in a
study with 6- to 8-year-olds Cain (1999) found that although
poor comprehenders did have poorer knowledge of metacog-
nitive strategies for reading when compared to readers their
own age, their comprehension performance was worse even
when compared to that of younger readers with the same
level of metacognitive ability. These mixed results probably
stem from the difficulty of ensuring that children and adult
readers use the strategy in the absence of continual monitor-
ing, together with individual differences in the efficiency
with which the strategy is performed.
Conversation
Conversation is an interesting case for comprehension.
Clearly, understanding a speaker’s meaning during conversa-
tion is essential to the successful progression and conclusion
of communication. For the most part, comprehension of oral
discourse follows the same principles as text-based compre-
hension. However, conversation is a unique form of compre-
hension in several ways. First, the purposes of conversational
comprehension and text comprehension usually differ. Con-
versations can be used to transmit information, but often
serve more human, social roles. Conversations involve ex-
change of information and may seek to amuse, entertain, or
punish. Consistent with these aspects of social interaction,
conversations are also unique in the process by which infor-
mation is added to conversation and the extent to which fre-
quent comprehension checks are made by both the speaker
and the comprehender during communication. Interestingly,
conversation requires frequent checks for comprehension be-
fore it can proceed; individuals contributing to a conversation
repeatedly and continually check understanding before con-
tinuing along a conversational path (H. H. Clark & Schaefer,
1989).
Just as background knowledge facilitates comprehension
of text, conversation involves what H. H. Clark and Schaefer
(1989) call common ground among participants. Common
grounddescribes the personal beliefs and knowledge that a
participant brings to the conversation. However, common
ground is not exactly like background knowledge, which re-
mains stable even as readers make connections between a
text and background knowledge and integrate text ideas into
the knowledge. Common ground is a more flexible entity—
it changes, is added to, or is destroyed and rebuilt during
the course of a conversation (H. H. Clark & Schaefer, 1989).
Comprehension checks called grounding(H. H. Clark, 2000;
H. H. Clark & Schaefer, 1989) continually assess the state of
common ground. Various techniques for grounding exist, but
they all elucidate the extent a speaker’s communicative intent
is clear to the listener. If grounding reveals a problem, a re-
pair is initiated to reestablish common ground before the rest
of the conversation can ensue.
Speakers do not ignore a listener’s background knowledge
when contributing to a conversation, but rather attempt to
modify their contributions based on their assessment of the
other’s knowledge. Isaacs and Clark (1987) studied experts
and novices participating in a conversation requiring knowl-
edge of New York City. These researchers found that the par-
ticipants were able to assess each other’s level of expertise
and modify their conversation accordingly. In their study, ex-
perts modified their contributions to be more explicit, and
during the task novices acquired specialized knowledge,
which could be used subsequently. Thus, the comprehension
of each utterance is not only evaluated, but the degree to which
common ground must be improved for successful communi-
cation is also assessed and modified. Unlike text comprehen-
sion, this assessment allows some potential comprehension
problems to be avoided before they are encountered.
According to H. H. Clark and Schaefer (1989), contribu-
tions in conversation serve not only to highlight misunder-
standings for clarification, but also to offer essential evidence
of successful understanding during the course of an exchange.
By the process of repeatedly checking understanding, the
common ground between participants in a conversation is
both established and added to in the course of the conversa-
tion. However, conversation can lack explicit links between
contributions and can require inferences by the other partici-
pants. H. H. Clark and Schaefer call the inferential processes
of conversationbridgingandaccommodation.Analogous to
text inferences, these conversational processes rely upon
knowledge and experience: Inferential processes add to the
understanding of the contribution just offered, and the inter-
pretation created by the inference often is made explicit by a
contribution from the participant making the inference.
Amazingly, participants pursue conversational goals, es-
tablish common ground, repeatedly check understanding,
make inferences, and continue to advance the conversation
more or less smoothly without noticeable lapses for processing