Journal of Psycholinguistic Research, Vol. 20, No. 3, 1991
A Sketchbook of Production Problems
Kathryn Bock1
.
Accepted February 5, 1991
This paper sets out five problems of language production that dominate current research
in the area. Four of them are problems that the f o d a t o r must solve in order to carry
out its functions. Consideration of these problems has spawned different theoretical
perspectives on and a variety of empirical findings about how the formulator works, and
these are briefly surveyed. The fifth problem is metatheoretical, and concerns the proper
domain of production theory.
The purpose of this paper is to identify some of the major themes in
research on language production. Over the past 15 years or so, work in
this area has rapidly made the transition from a psycholinguistic hobby
to a central enterprise in the study of language performance. Although
the focal problems are in many ways similar to those of language comprehension, there are important differences that help to make the study
of production distinct. I will sketch five problems, starting with the one
that serves as a major force in dividing the issues of production from
those of comprehension, and briefly illustrate how these problems have
been addressed in current theory and research. Four of the problems are
This paper is adapted from a talk that introduced the Special Session on Language
Production at the Third Annual CUNY Conference on Human Sentence Processing. 1
am grateful to the other participants in the session (Gary S. Dell, Merrill F. Garrett,
W.J.M.Lcvelt. David D. McDonald. and Stcfanie Shattuck-Hufnageo for their contributions to this paper, and to Janet D. Fodor for making time stand still. Preparation
of the manuscript was supported by grants from the National Science Foundation (BNS8617659) and the National Institutes of Health (R01-HD21011).
' Address all correspondence to Kathryn Bock, Department of Psychology, Psychology
Research Building, Michigan State University, East Lansing, Michigan 48824-11 17.
141
0090.690519 1/0500-014 1106.50/0 0 1991 Plenum Publishing Corporation
142
Production P r o t
Bock
processing challenges that the production system must meet, and the last
is a question about the domain of a production theory.
Presenting the big problems requires a solution to a little problem
of terminology. There is no very satisfactory label in general use for the
cognitive apparatus that is responsible for producing language. The natural complement to the parser would seem to be the articulator, an
apparatus that joins pieces together into systematic units. But that term
is ambiguous and, in its dominant meaning, too toothy and lippy to
adequately capture the higher-level linguistic processes that give rise to
speech. As an alternative, I will refer to the formuiator, borrowing the
term from Levelt's compleat introduction to the problems of production
. - . . - -.-(Levelt, 1989).
.--.
THE FIVE PROBLEMS
The five sections that follow present the five problems. In order,
they are (1) getting the form right; (2) regulating information flow; (3)
fluency; (4) coordination; and (5) type transparency.
Regulating In)
Getting the Form Right
The goal of comprehension is to create an interpretation of an utterance. The goal of production-at least the speaker's immediate goalis simply to create an utterance. That utterance should be adequate to
convey the speaker's meaning, but it must also meet a range of constraints that we think of in terms of the grammar. And that gives the
production problem a different spin. As Garrett (1980) put it, "The
production system must get the details of form 'right' in every instance,
whether those details are germane to sentence meaning or not." So, a
very general problem for a theory of production is to explain how speakers create linguistic structures at all levels.
This difference between production and comprehension can lead to
somewhat different evaluations of the role and the importance of structure
in general, as well as structures in particular. Subject-verb agreement
offers an illustration. This type of agreement carries little of the burden
of interpretation in English, and in line with this, there are studies of
comprehension which show that readers are all but oblivious to agreement
violations such as Some shells is even soft at the same time that they are
keenly aware of the problem with Sometimes the diamondback swims in
the open sea but it usually lives in salt shakers and tidal rivers (Kilborn,
1988; Kutas & Hillyard, 1983). This tends to engender the idea that
agreement is
surprisingly st
In several expi
conditions knt
ments 1 and 2
they could ha'
In genera
Tape-recorded
prone than in
fences, Deese
yielding a rate
sentences. Otl
and word-leve
of spontaneou
ishingly low. '
of form right.
\
Somewhi
creating acce]
leads to a pro1
like this: A s
respect, has ey
tures and inte
The speaker r
pretation. Thc
creating a stn
sequence, we
Table I. Estirr
the Deese (I!
Corpus
Deese (1984)
London-Lund
2
Brian MacWhi
for the speaker
143
production Problems
agreement is all but irrelevant to the use of English. Yet speakers are
surprisingly scrupulous in their observation of subject-verb agreement.
In several experiments that were designed to elicit agreement errors under
conditions known to predispose them. Bock and Miller (1991. Experiments 1 and 2) observed errors in less than 5% of the utterances in which
they could have occurred.
In general, speakers are very good at creating acceptable utterances.
Tape-recorded corpora reveal that everyday speech is much less errorprone than intuition might suggest. In a corpus of nearly 15,000 sentences, Deese (1984) found just 77 that could not be parsed sensibly.
yielding a rate of just five serious structural anomalies for each thousand
sentences. Other errors are also rare. Table I gives the rates of soundand word-level errors per 10,000 words from two tape-recorded corpora
of spontaneous speech. Though the rates differ slightly, both are astonishingly low. The production system does. in fact, tend to get the details
of form right.
Regulating Information Flow: The Full-Deck-of-Cards Paradox
Somewhat strangely, speakers actually may be more successflil at
creating acceptable forms than at conveying intended messages. This
leads to a problem that I will call the full-deck-of-cards2 paradox. It runs
like this: A speaker knows the communicative intention and. in that
respect, has every advantage over comprehenders, who must piece structures and interpretations together from degraded and ambiguous input.
The speaker merely has to create structures that convey a known interpretation. The paradox is that speakers can be simultaneously adept at
creating a structure and inept at conveying an interpretation. As a consequence, we get a central fact about speech errors: They obey structural
Table I. Estimated Rates per 10,000 Words for Sound and Word Errors from
the Deese (1984) and London-Lund (Gamham. Shillcock. Brown, Mill, &
Corpus
-
Dcese (1984)
London-Lund
Cutler. 1982) Corpora of Spontaneous Speech
Estimated rates per 10.000 words
Sound errors
Word errors
.1.3u
e
,
.
3.20
2.50
5.10
.
.
.-
.
Bock
Produ
constraints at the same time that they egregiously violate the intended
to m:
flow
One of the best-known structural constraints concerns form classes.
The form-class constraint i s reliably illustrated in such errors as word
exchanges, when two words transpose (e-g., The speakers of the minds
of that community, in which minds and speakers traded places); semantic
substitutions, in which a word that means something similar to the intended word substitutes for it (e-g., Until now, just do it, where now
replaces the intended word then); and phonological substitutions, in which
a word that sounds similar to the intended word substitutes for it (e-g.,
He's the kind of man that soldiers look up toand try to emanate, where
emanate replaces emulate). None of the sample errors successfully conveys the speaker's intended meaning, but all of them obey syntactic
constraints, because the words that interact in creating the errors represent
the same form classes (for word exchanges, between 80% and 85% of
spontaneous speech errors obey the form-class constraint, and for word
substitutions, nearly 100% represent the form class of the intended word;
Garrett, 1980; Stemberger, 1985).
Errors that involve bound morphemes rather than full words (e-g.,
It'll get fast a lot hotter i f you put the burner on, when hot a lot faster
was intended) likewise obey syntactic constraints as a result of affix
stranding: Only the word stem moves (this is true for approximately 90%
of such errors; Stemberger, 1985). In similar fashion, sound-level errors
obey phonotactic constraints, creating acceptable phonological structures. So, analogous to the form-class constraint, there is a sound-class
constraint on errors: Consonants interact with other consonants (e.g.,
Jashon and Josua when Jason and Joshua was intended), and vowels
with other vowels (e.g., surplus accipital activity when occipital activity
was intended) and originate in the same positions in words or syllables.
The full-deck-of-cards paradox may be more apparent than real,
though, because "playing with a full deck" may not be an especially
good thing for a speaker who is forced by the constraints of the vocalauditory channel to say one thing at a time. If one knows, at some level,
much more than one can conveyat a given moment, a great deal of work
must go
into not saying a lot of things, in order to say the right things
at the right time. The availability of information other than that which
is actually spoken and the deleterious potential of that availability are
evident in the prevalence of contextual errors-errors more often than
not have an identifiable source somewhere in the intended utteranceand in the predominance of anticipatory over perseveratory errors. So,
begir
flood
rett's
1988
repre
spon
built
item:
func
t (V)(
this
thou
the 1
. ogic
,the 1
tern
fransion
4
!
:
1
I
!
,
..
.I1
1
I
I
.
gwe
Dell
retri
I
h
an<
inf
is
for
int
19
!
P"
an
cl;
fre
ne
[hi
AI
sa
PC
production Problems
I
I
b
i1
I
145
to mix metaphors, the full deck of cards gives rise to a torrent whose
flow must be continuously regulated.
But there are leaks. And those leaks, in the form of speech errors,
begin to reveal the design of the machinery that ordinarily controls the
flood. One influential analysis of errors is that of Merrill Garrett. Garrett's analysis motivates a model of the production process (Garrett,
1988) that is shown in Fig. 1. Briefly, there are three levels, the topmost
representing the intended message. The remaining two levels are responsible for putting the linguistic pieces of utterances together. One
builds the functional-level representation by assigning selected lexical
items from the lexical set to syntactic functions within clauses; these
functions are represented a s the slots in the functional structure
((V)(S(V)(N)(N))). The phonological forms of words are irrelevant to
this assignment, as is the eventual order of the words in the utterance,
though the form classes of words are critical. The second level creates
the positional-level representation, where both word order and phonological forms are specified within phrases. Word forms are retrieved from
the lexicon and their segmental and prosodic features are assigned to the
terminal elements of the constituent structure or positional-level planning
frame (see Shattuck-Hufnagel, 1979, 1987, for a more detailed discussion of how this second level might be o r g a n i ~ e d ) . ~
The levels of the model neatly explain the complex error, The skreaky
p e a s e gets the wheel, which was observed by Garrett4 and analyzed by
Dell (1989) in the following fashion. Initially, wheel and grease are
retrieved from the lexical set and assigned the wrong syntactic functions
I
I have omitted a controversial set of processes that follow the assignment of segmental
and prosodic structure. In Garrett's scheme these processes interpret and site node
information (Ganett, 1988). that is, they insert the elements of the closed class. There
is considerable disagreement about whether the phonological interpretation of these
forms is different from that of the open class (see Dell. 1990). whether the forms are
inherent in positional frames in the way that this mechanism seems to require (Bock,
1989). and whether the closed class constitutes a separable vocabulary of the language
processor, as their peculiar vulnerability in aphasic disorders seems to suggest (aphasics
are generally better at dealing with high- than with low-frequency words, but closedclass words are disproportionately absent from aphasic speech despite their very high
frequencies of occurrence in normal speech; Garrett, 1990). Garrett (1990) presented
new evidence from speech errors to counter the hypothesis that it is word frequency
that is responsible for most of the differences between the open and closed classes.
Among those word-exchange errors involving open- or closed-class words from the
same frequency ranges, open-class errors predominated.
' Personal communication. November 1, 1988.
J
Production Problems
Bock
7
Inferential processes
Message representation
of functional
structures
selection
1
{
Lexical'assignment
t
Functional level representation
\
.
,
Ñ
Assignment of segmental and
prosodic structure for words
Positional level representation
Fig. 1. A model of language production (slightly modified from Garrett, 1988).
in the functional structure (wheel becomes the object and grease the
subject). That functional error eventuates in the placement of grease in
the same phrase wil
frame, and sets up
and HI. That excha
This analysis
rationalizing error 1
ambitious. It is als
tion. The need to 1
and the model's ml
this is achieved. Ji
modularity (Fodor,
modular, since it m
are capable of exp
many errors is enol
far downstream. C
severe restriction c
that level are sensi
A related rest
Because everythin
discrete stages of
up influence f r o m
retrieval side, one
errors that have be
and Levelt (1983)
mother for wife, i
phonological WOK
catalog, consider4
rett, 1988). Like\
ological affinities
(1981) and Marti
occurrence of phc
ceeds chance exp
the levels of lexi
of the lexicon in
composition can
thereby making 11
errors (for differ1
1991; Schriefers,
Despite its i
of lexical retriev
that there are un
the syntax and a
Production Problems
147
the same phrase with and next to squeaky in the positional-level planning
frame, and sets up the conditions for the sound exchange between /w/
and /r/. That exchange in turn yields sbeaky gwease.
This analysis illustrates something about the theory's successes in
rationalizing error patterns, but the model's goals are considerably more
ambitious. It is also intended to explain the features of normal production. The need to regulate the flow of information is one such feature,
and the model's modular design constitutes a strong proposal about how
this is achieved. Jerry Fodor pointed out in a footnote to his essay on
modularity (Fodor, 1983) that it makes little sense for production to be
modular, since it must be open to the full range of information that people
are capable of expressing. Sense aside, though, the weird semantics of
many errors is enough to suggest that this openness does not extend very
far downstream. Garrett's model proposes that, at each level, there is a
severe restriction on the kinds of information to which the operations at
that level are sensitive.
A related restriction is evident in the direction of information flow.
Because everything proceeds from the top down, there are relatively
discrete stages of semantic and phonological retrieval, with no bottomup influence from the positional to the functional level. On the lexical
retrieval side, one argument for this is found in the word substitution
errors that have been discussed by Garrett (1980), Fay and Cutler (1977),
and Levelt (1983): Semantic word substitutions (e-g., sword for arrow,
mother for wife, listen for speak) show few similarities in form, while
phonological word substitutions (mushmom for mustache, cabinet for
catalog, considered for consisted) show few similarities in meaning (Garrett, 1988). Likewise, exchanged words d o not seem to have the phonological affinities that exchanged sounds do. However, Dell and Reich
(1981) and Martin, Weisberg, and Saffran (1989) have shown that the
occurrence of phonological similarities among semantic substitutions exceeds chance expectations, leading to questions about the strictness of
the levels of lexical retrieval. Dell (1986) has proposed that the levels
of the lexicon interact during retrieval, so that a word's phonological
composition can affect the accessibility of its semantic representation,
thereby making lexical processing a major culprit in the leaks that yield
errors (for different perspectives, see Butterworth, 1989; Levelt et al.,
1991; Schriefers, Meyer, & Levelt, 1990).
Despite its differences from Garrett's model over the mechanisms
of lexical retrieval, Dell's model shares with Garrett's the assumption
that there are uniform levels of syntactic construction, thereby making
the syntax and other structural processes the major regulators of infor-
148
Bock
mation flow. If this assumption is right, supposed message-level features
should have little effect on structural processes at the positional level. In
line with this prediction, there are results which suggest that the processes
that construct hierarchically and serially arranged sequences of words are
not directly sensitive to the semantic or pragmatic burden of sentence
constituents.
Much of this evidence rests on a structural priming phenomenon
which appears to reflect the process of creating constituent structures.
The phenomenon itself is simply a tendency to produce sentences in
structures similar to those of recently produced sentences. This tendency
appears to persist regardless of changes in discourse structure (Estival,..
1985), changes in the thematic roles of the sentence constituents (Bock
& Loebell, 1990), changes in the semantic features of the sentence constituents (Bock, Loebell, & Morey, in press), and changes in the closedclass elements in the sentences (Bock, 1989). It disappears after a change
in the constituent structures of the sentences involved (Bock & Loebell,
1990), even when metrical structures are held constant. The implication
is that the processes that form the positional representation, building the
bridge from the functional to the positional level, operate without the
guidance of message features. This accords with the idea that the flow
of information during production may be regulated by heavily restricting
the access of processes to different types of information.
The obverse of the problem of regulating information is the problem
of fluency. Though it may be essential to restrict the top-down flow of
information during production in order to reduce interference from extraneously or contemporaneously available information, it is also important to keep speech flowing smoothly, without long hesitations and
interruptions (Clark & Clark, 1977). Speakers are not entirely successful
at doing this, of course, but the rate at which speech is produced is
nonetheless impressive. Levelt (1989) emphasizes just how big a feat it
is: At a normal speaking rate, speakers select a word roughly once every
400 ms from a vocabulary that he puts in the range of 30,000 words.
Because of the normal fluency of speech, it is natural to assume
that the formulator is organized and operates in a way that meets the
demands of creating utterances in time. This has the potential to conflict
with the need to regulate information during production. On one side,
the formulator must staunch the flow of information, and on the other,
keep it moving.
To see the problem, consider a possible implication for fluency of
Production Problems
,
!
I
I
the organization of the model in Fig. 1. In order to ensure that only
information which can be integrated into the developing utterance is
passed to the next processing level, suppose that the functional representation of each utterance is fully formatted before positional processing
commences, and the positional representation fully formatted before motor programming commences, and the motor program fully formatted
before articulation commences. If so, speech might typically proceed in
bursts punctuated by silence, as each utterance is formulated from the
functional level on down. This violates the intuitions of both speakers
and hearers.
--- . .
Part of the formulator's solution to the problem seems to be to
specify progressively narrower windows or units at each level, creating
a processing hierarchy. In terms of the model in Fig. 1, the units at the
functional level are larger than those at the positional level, and so on
down, allowing an utterance to be initiated without being fully prepared
at every level. On the basis of speech-error evidence, Garrett (1988)
proposed that the functional level spans about two clauses, while the
positional level spans about a phrase. The error evidence is found in the
typical scope of word exchanges, which is generally no more than two
clauses, and the typical scope of sound exchanges, which is generally
no more than a phrase. Since word exchanges seem to be consequences
of syntactic-function misassignments and sound exchanges seem to be
consequences of phonological-segment tnisassignments, the scope of such
errors offers one index of the scope of the operations that normally
perform these tasks (also see Ford, 1982; Ford & Holmes, 1978). Other
evidence comes from experimental findings which show that the meanings of both the subject and the object of a to-be-spoken sentence may
be active at a point in time when only the phonological form of the head
of the subject noun phrase is active (O'Seaghdha, Dell, & Peterson,
1988). At lower levels, the processing windows may be narrower still.
Stemberg, Knoll, Monsell, and Wright (1988) offer evidence from studies of planned speech that the stress group or metrical foot (a single
stressed syllable and its accompanying unstressed syllables) is the basic
unit of the motor program.
Consistent with such a hierarchical arrangement, the units at different levels seem to interact differently with the realization of grammatical
features. Bock and Cutting (1990) explored the occurrence of subjectverb agreement errors following phrasal vs. clausal subject-postmodifiers
(e.g., The claim about the newborn babies. . vs. The claim that wolves
had raised [he babies. . .) in which the lengths of the postmodifiers were
equated in number of syllables. In these experiments, the task was simply
.
Production Problems
Bock
IS0
to produce a completion for each sentence fragment, and the dependent
measure was the number of verb-agreement errors that speakers produced
in their completions (see Bock & Miller, 1991). Extrapolating from find- .
ings in comprehension (Caplan, 1972; Jarvella, 1971), the prediction
would be that such errors should be more frequent after clauses than after
phrases, due to a general tendency to forget the form of material preceding the most recent clause. The hierarchical formulation hypothesis
predicts just the opposite. Grammatical agreement is defined over clauses
and, on the assumption that clauses constitute a unit of formulation at
the level at which agreement is implemented (the functional level, where
subjects are specified), agreement should be relatively uninfluenced
.
.-.
-by . .---material outside the clause in which a given verb occurs.
The actual result was in line with the hierarchical hypothesis: Speakers made significantly more errors after phrasal than after clausal postmodifiers. Notice that the erroneously agreeing verb in The claim about
the newborn babies were. . . i s in the same clause with the apparent
source of the error, whereas in The claim that wolves had raised the
babies were. . the erroneously agreeing verb is in a different clause,
the matrix clause. If clauses constitute a formulation unit, such that the
contents of constituent phrases within a clause are free to interact in a
way that the contents of constituent phrases from different clauses are
not, the agreement-error results follow.
From a theoretical standpoint, the specification of such units is essential to meaningful contrasts between modularity and interactivity in
production (or any fluid ability). In a modular system, processes are
defined in terms of the vocabularies or information types to which they
are responsive, and in a constructive modular system, one process must
hinge on another, with one's product serving as the other's raw material.
T o empirically distinguish such an arrangement from an interactive
processing system, there must be some specification of the scope of each
process that predicts the points at which different types of information
come into play.
.
Coordination
The coordination problem arises because production is, in fact, productive: The utterances we produce are rarely memorized sequences, but
rather creative assemblies of elements within structures. Words must be
put into place in syntactic structures, and sounds must be put into place
within phonological structures. The problem is evident in the architecture
of the model in Fig. 1: At the functional level the members of the lexical
set must be assigned to the proper syntactic functions, and at the posi-
tional level the phc
into the right place
The argumenl
of coordination fir
other elements of
shows that words
than other units su
is that such eleme
structures,
are
processing but
system
1
t
Another argi
nomenon of accoi
tures appropriate t
rightly to bear th
subject function.
w e can rarely de
when pronouns a;
the world should
rett, 1980). Sim
tioned, they see
environment. In
tended; Fromkin
1
*
iI
i
I
..
. .'*'
<r '
.
..-
SENTENCE
.
PHRASI
f
'*Â
..
.
2'
fc
1
i
"
->
WORt
MORPHEM'
>SYLLABL
g
SYLLAEL
Â
VCORC
CLUSTE
f
PHONEN
FEATUF
Fig. 2. Percentage
similar graph pres
should be used foi
151
Production Problems
tional level the phonological segments of the word forms must be slotted
into the right places.
The argument that words and phonological segments are the targets
of coordination finds support in evidence that they are more likely than
other elements of utterances to turn up in the wrong places. Figure 2
shows that words and segments are more likely to participate in errors
than other units such as phrases or features or syllables. The implication
is that such elements are not retrieved as pans of larger, more unitary
structures, but are manipulated, placed, and misplaced as pieces by the
processing system.
Another argument for a coordination process comes from the phe-nomenon of accommodation, in which misplaced elements take on features appropriate to their environment. For example, something that ought
rightly to bear the object function might be inadvertently assigned the
subject function. Because English does not routinely mark case overtly,
we can rarely detect case-marking accommodations, but they do occur
when pronouns are involved, as in the error He offends her sense of how
the world should be (when She offends his sense.
was intended; Garrett, 1980). Similarly, if phonological segments are improperly positioned, they seem to take on the features appropriate to the new
environment. In the error lumber s p a m (when slumber party was intended; Fromkin, 1973) a word-initial /p/ mistakenly follows the initial
/
.
..
oe
0
>SYLLABLE
SYLLABLE
VCORCV
SOUND UNITS
--
FEATURE
0
I
I
I
10
20
30
40
PERCENTAGE OF ERRORS
Fig. 2. Percentages of speech errors involving various linguistic units (modeled after a
similar -graph
. presented by Dell. 1987). The percentages are rough approximations and
should be used for ordinal comparisons only.
'
-
-
Production Problem
Bock
/sf, and the Ipf should no longer be aspirated. The implication here is
that various structural positions or relations impose requirements on the
elements that fill them, requirements that are not features of the elements .,
themselves.
T o solve the coordination problem, the formulator must know how
to put the pieces of language into their proper places in utterances. Naturally, the pieces that have received the most attention in efforts to
explain how the formulator solves this problem are those pieces that most
obviously require coordination, words and sounds.
Words themselves have two logically separable components, a
meaning and a phonological form. As a result, we have the same meaning
expressed in different phonological forms (e.g., pail a i d bucket) andm---different meanings expressed in the same phonological form (e-g., savings bank and river bank). If these components are represented separately
as well, their coordination with the relevant structures may also be a
twofold affair. Again in terms of the model in Fig. 1, abstract specifications of words (presumably including their semantic specifications, but
not their phonological specifications) are hypothesized to b e linked to
syntactic functions at the functional level, but the sound segments are
not put into place until the positional representation is constructed.
. !
One orediction that follows from dividing the coordination pioblem
.iI
up in this way is that variations in the states of preparation of the mean. '\ .
.
n g s of lexical entries should have a greater impact on the syntax of an
utterance than variations in the states of preparation of the phonological . . '
forms of words. The prediction follows from the role of the functional
representation in guiding the creation of a syntactic structure, via assignments to such syntactic functions as subject and direct object.
This was tested in two experiments that compared the effects of
semantic and phonological priming on the arrangements of words in
sentences (Bock, 1986). The participants received priming words that
were either semantically or phonologically related to various target words,
under conditions that disguised the priming manipulation. T h e target
words appeared as the subjects or objects of sentences that were extemporaneously created by the participants themselves to describe pictured
events which followed the presentation of the priming words. For example, one speaker might have received the word thunder followed by
a picture of lightning striking a church, while other speakers received
the words worship, frightening, or search. The two target words were
Zighming (semantically primed by thunder and phonologically primed by
frightening) and church (semantically primed by worship and phonologically primed by search). The question was whether the subject and
'
object assignment
varied (and along
on whether the a;
The results s
tion assignments
mantically prime'
an active or passi
primed targets w
were primed tha
,
meanings of woi
differential prim
,
effect.
This result
ordination. Howl
of the phonologi
on functional as
work (Bock, 191
reliable effect o
assume, in line 1
effects on semar
- " ..
lexical errors, t
- , activation of ph
in the lexical se
-- . tional structure.
KT-'-proceeds in dis
**.
-Ç.-"
* r.ff- form.
'Phonologi(
.-..I
'ical o r phonolo;
and some deba
the phonologic:
the odd fact th
stored word fc
should occur (
words). Why s
I
Shattuck-1
!
occurs
because
!
that transform
are misplaced
developing mt
Evidence for t
ences between
8
. , ' J
;
¥È
,.Ã̂
"
I
Production Problems
153
object assignments in the sentences that were produced by the participants
varied (and along with them, the structures of the sentences), depending
on whether the agent (lightning)or recipient (church) was primed.
The results suggested that semantic priming affected syntactic-function assignments in a way that phonological priming did not. The semantically primed target reliably tended to serve as the subject of either
an active or passive sentence, as appropriate, whereas the phonologically
primed targets were not used as subjects reliably more often when they
were primed than when they were not. So differential priming of the
meanings of words may change their functional level assignments, but
differential priming of the sounds of words did not have as strong an
.- . . - -.-effect.
This result is clearly consistent with the model's conception of coordination. However, the model also predicts that the state of preparation
of the phonological forms of words should have no influence whatsoever
on functional assignments, and this turns out to be too strong. In other
work (Bock, 1987), I have found that phonological priming can have a
reliable effect on sentence form. One way to accommodate this is to
assume, in line with Dell and Reich's (1981) explanation of phonological
effects on semantic substitutions, word exchanges, and other higher-level
lexical errors, that such interactions are mediated by the lexicon: The
activation of phonological forms affects the state of any affiliated items \
in the lexical set, which may in turn affect the determination of a functional structure. This requires weakening the view that lexical retrieval
proceeds in discrete stages involving the access of meaning and then
form.
Phonological coordination, the problem of putting sounds into lexicai or phonological structures, is currently the object of intense scrutiny
and some debate. Especially at issue is a question about the nature of
the phonological planning frame, a question which follows in part from
the odd fact that phonological segments move despite the existence of
stored word forms which specify the order in which sound segments
should occur (forms that allow us, among other things, to recognize
words). Why should sounds move around at all?
Shattuck-Hufnagel (1987; also see Levelt, 1989) suggests that this
occurs because connected speech requires building a metrical structure
that transforms the phonological segments in various ways. Segments
are misplaced when they are copied from the stored template into the
developing metrical structure, which incorporates the planning frame.
Evidence for this view comes from experimentally demonstrated differences between errors that arise in the production of disconnected words
Bock
Product!
and those that occur in connected speech (Shattuck-Hufnagel, 1987). In
the former, there were a disproportionate number of word-onset errors
relative to errors in other word positions, while in the latter, more errors
appeared for non-onset consonants.
Dell (1986) also proposed a coordination mechanism in which sound
segments are associated with phonotactic frames, although the segmentretrieval mechanism was modeled as a process of spreading activation in
a lexical network. Dell (1990), in contrast, has developed a paralleldistributed-processing model (similar to that of Jordan, 1986) in which
frames are epiphenomenal, an emergent property of the features of the
stored segments and the network in which they'are represented. According to this model, the frame-like regularities of errors are a product of
the similarities and the sequential biases characteristic of segment combinations in English. This redefines the coordination problem, since segments sprout frames rather than having to be attached to them.
Dell's (1990) new model is designed to simulate the qualitative and
quantitative features of noncontextual sound errors, errors that have no
obvious source in the immediate linguistic environment, and its performance on that score is impressive. It remains to be seen whether the same
architecture is adequate to account for the more common contextual errors, whose distribution and features were the focus of Dell's earlier
effort (1986). Dell (1990) suggests that the error types may, in fact, be
disparate. If so, the coordination problem remains.
tional
distingi
154
Type Transparency
.
The question of type transparency (Berwick & Weinberg, 1984),
applied to production, is whether the organization of the formulator mirrors the logical organization of rules and structures in the grammar. There
seems to be an irrepressible desire on the part of many linguists and
psycholinguists to equate the components of production models with the
components of one or another syntactic theory, partly due to a confusion
of the behavioral notion of generation with the mathematical notion of
generation that is relevant to generative grammar. They are distinct.
There are other divergences, too. Garrett (1980) noted that errorbased production models (including his own) are grounded in a type of
data that is dramatically different from traditional linguistic evidence.
For that reason, the model is agnostic about many things. T o take one
example, the functional-level representation in Fig. 1 is not equated with
any of the plausible candidates from linguistic theory (e.g., D-structure
or S-structure in government-binding theory; f-structure in lexical-func-
BI
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Production Problems
,
155
tional grammar), because the error data do not provide any grounds for
distinguishing among them.
But as Garrett (1980) also noted, the differences in methods and .
goals make those similarities that do arise between production theory and
linguistic theory all the more important. Whenever such disparate lines
of inquiry converge on such similar pictures, one's faith in the picture's
veridicality increases. Fromkin's (1971) classic paper detailed the convergences between the units of linguistic theory and the units that participate in speech errors. Fromkin (1971), Garrett (1975), Sternberger
(1985), Dell (1986), and others have found that an explanation of the
error data requires separating the domains of formulation along lines very. . .
similar to the partitions found in most linguistic theories: There is a
domain in which sentence structures are formed (a syntax), a domain in
which sound structures are formed (a phonology), and a domain that
mediates between the two (a lexicon or morphology).
Though it is possible to construct much more fine-grained analogies
between theories of production processes and theories of grammar, questions have been raised about how directly our knowledge of language is
manifested in or adapted to our use of language (Chomsky, 1986) and
therefore about how responsive a linguistic theory should be to performance data or, for that matter, a performance theory to linguistic data.
There is no consensus about this in linguistics, though some linguists
appear to regard the study of language processing as a relevant and
potentially valuable source of evidence about language structure (Ades
& Steedman, 1982; Bresnan, 1978; Bresnan & Kaplan, 1982). For the
sake of consistency, at least, any linguist who regards children's language
performance (almost always, children's language production) as a central
source of evidence about how language is represented must acknowledge
the relevance of adult language performance (including adults' language
production).
In psycholinguistics, there is considerable scepticism that linguistic
theory will have anything to say about the fundamental mechanisms of
language processing, in part due to the failures of earlier efforts to adapt
competence theories to the domain of language performance (see Fodor,
Bever, & Garrett, 1974, for a summary). Because performance mechanisms are beyond the reach of introspection and intuition, an experimental approach is required to tap processing in ongoing time. Still, the
received view is that the processing system must be organized in such a
way that i t yields the structural regularities that emerge from linguistic
analyses (Fodor and Garrett, 1966). Although relatively little has been
done by way of casting alternative linguistic construals of language struc-
156
Bock
tures into production hypotheses (though see Bock et al., in press; Stemberger, 1990), it can be expected that linguistic theory will serve as an
important influence on the development of models of the formulator. The
obvious reason is that an explanation of structure is the focus of linguistic
theory, and an explanation of the creation of structure is the focus of
production theory.
CONCLUSION
The foregoing collection of sketches sets out some, but by no means
all, of the focal problems in research on language production. These
problems are sometimes judged to be either less open to solution or less
interesting (or both) than the problems of language comprehension, and
one purpose of this sketchbook has been to try to counter such impressions.
The study of production has certainly been more trying than that of
comprehension. It has gone forward thanks primarily to the tenacity and
creativity of a few dedicated collectors of speech errors, who enjoy one
advantage. Whereas the heavy industry of the study of parsing is devoted
to the development of ingenious means for tapping into ongoing processes,
formulation has the convenient property of wearing its ongoing processes
on its sleeve: In both fluent and dysfluent speech, we have direct access
to the final products of the formulator. Though w e assuredly do not have
perfect access to the underlying details, either as introspective speakers
or as curious investigators, w e often have readily observable indications
of where and when in the development of an utterance things are proceeding smoothly and where and when they are not, and in errors, w e
can sometimes detect the actual source of the disruption.
But the successful construction and interpretation of processing models
rests on the deployment of carefully targeted experimental methods. As
valuable as the analysis of spontaneous speech errors has been in establishing the bedrock regularities of formulation, the enterprise is limited
in its ability to evaluate competing hypotheses. The linguistic and extralinguistic contexts of natural errors may vary freely in ways that bear
both on the occurrence of error and on the validity of different explanations, making some form of experimental control essential. That has
been a sticking point in the development of research on language production, but pathways have begun to open with the invention of an array
of methods for the study of phonological, lexical, and syntactic encoding.
Despite the problems that it poses for the investigator, from the
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Production Problems
157
standpoint of the language user it may seem that production is inherently
less challenging than comprehension. The fascination of the puzzle of
comprehension comes from our mysterious ability to solve a problem
with two unknowns: At the beginning of an episode that ends in understanding, the listener knows neither the meaning nor the form in which
it will be conveyed, and the process of solving for both is extraordinarily
vexed. The fascination of the puzzle of production comes from our mysterious inability to solve a problem that is, from a computational perspective, trivial (Ristad, 1990): Given a message to be conveyed, perfect
forms can be generated by any of many different algorithms. Human
speakers are, indeed, good at generating perfect forms. The mystery is
that those forms can have annoyingly little to do with the intended meaning.
The importance of a solution to this puzzle goes beyond its implications for our understanding of production itself. Explaining how the
language processor works in a domain where structures can be formed
on the basis of relatively rudimentary features of meaning may help in
explaining how structures can be formed when the meaning is, in fact,
unknown. In this sense, the explanation of production may contribute to
an explanation of comprehension as well as to the development of a
general theory of language performance.
\
REFERENCES
Ades, A. E.. A Steedman, M. J. (1982). On the order of words. UngwStics and Philosophy, 4 , 517-558.
Berwick, R. C., & Weinberg, A. S. (1984). The grammatical basis of finguistic perfonnance. Cambridge, MA: MIT Press.
Bock, J. K. (1986). Meaning, sound, and syntax: Lexical priming in sentence production.
Journal of ExperUnental Psychology: Learning, Memory, and Cognition, 12, 575586.
Bock, J. K. (1987). An effect of the accessibility of word forms on sentence structures.
Journal of Memory and Language, 26, 119-137.
Bock, J. K. (1989). Closed-class immanence in sentence production. Cognition, 31,
163-186.
Bock, J. K., & Cutting, J. C. (1990). Production units and production problems in
forming long-distance dependencies. Paper presented at the meeting of the Psychonomic Society, New Orleans, LA.
Bock, 1. K., & Loebell, H. (1990). Framing sentences. Cognition, 35, 1-39.
Bock, J. K.. Loebell, H., & Morey, R. (in press). From conceptual roles to structural
relations: Bridging the syntactic cleft. Psychological Review.
Bock, J. K., & Miller, C. A. (1991). Broken agreement. Cognitive Psychology. 23, 4593.
Brcsnan. J. (1978). A realistic transformational grammar. In M. Halle, J. Brcsnan, &
Bock
158
G. A. Miller (Eds.), Unguistic theory and psychological reality (pp. 1-59). Cambridge, MA: MIT Press.
Bresnan, J., & Kaplan, R. M. (1982). Introduction: Grammars as mental representations
.,
of language. In J. Bresnan (Ed.), The mentalrepresentaticn ofgrammaticalrelations
(pp. xvii-lii). Cambridge, MA: MIT Press.
Butterworth, B. (1989). Lexical access in speech production. In W. D. Marsh-Wilson
(Ed.), Lexical representation and process (pp. 108-135). Cambridge, MA: MIT
Press.
Caplan, D. (1972). Clause boundaries and recognition latencies for words in sentences.
Perception & Psychophysics. 12, 73-76.
Chomsky. N. (1986). Knowledge of language: Its nature, origin, and use. New York:
Praeger.
Clark. H. H., & Clark, E. V. (1977). Psychology and language: An introduction to
psycholinguistics. New York: Harcourt Brace Jovanovich.
- ----.Deese, J. (1984). Thought into speech: The psychology of a language.&g~&ood Cliffs,
NJ: Prentice-Hall.
Dell. G. S. (1986). A spreading-activation theory of retrieval in sentence production.
Psychological Review, 93, 283-321.
Dell, G. S. (1987, July). Phonological encoding in production. Lecture in the course
"Language comprehension and production" (G. S. Dell & M. K. Tanenhaus, instructors), Linguistic Society of America Summer Institute, Stanford University,
Stanford, CA.
Dell, G. S. (1989. March). Languageproduction and connectionist models of the mind.
Colloquium presented to the Department of Psychology, Michigan State University,
East Lansing, MI.
Dell, G. S. (1990, March). Frame constraints and phonological speech errors. Paper
. presented at the CUNY Conference on Human Sentence Processing, New York,
NY.
Dell, 0.S. (1990). Effects of frequency and vocabulary type on phonological speech
errors. Language and Cognitive Processes, 5,313-349.
Deil, G. S., & Reich, P. A. (1981). Stages in sentence production: An analysis of speech
. error data. Journal of Verbal Learning and Verbal Behavwr, 20, 611-629.
Estival, D. (1985). Syntactic priming of the passive in English. Text, 5, 7-21.
Fay, D., & Cutler, A. (1977). Malapropisms and the structure of the mental lexicon.
Linguistic Inquiry, 8, 505-520.
Fodor. J. A. (1983). The modularity of mind. Cambridge. MA. MIT Press.
Fodor. J. A.. Bever. T. G.. & Garrett. M. F. (1974). Thepsychology of language. New
York: McGraw-Hill.
Fodor, J., & Ganett, M. (1966). Some reflections on competence and performance. In
J. Lyons & R. J. Wales (Eds.), Psycholinyuticspapers (pp. 135-154). Edinburgh:
Edinburgh University Press.
Ford, M. (1982). Sentence planning units: Implications for the speaker's representation
of meaningful relations underlying sentences. In J. Bresnan (Ed.), The mental representation of grammatical relations (pp. 797-827). Cambridge. MA: MlT Press.
Ford, M., & Holmes, V. M. (1978). Planning units and syntax in sentence production.
Cognition, 6, 35-53.
Fromkin, V. A. (1971). The non-anomalous nature of anomalous utterances. Language.
47, 27-52.
Fromkin, V. A. (1973). Speech errors as linguistic evidence. The Hague: Mouton.
Production Probler
Gamham. A.. ShiIIc
Slips of the ton
Cutler (Ed.), S
Mouton.
Garrett. M. F. (197
psychology of 1
Garrett, M. F. (19s
(Ed-),
Languor
Garrett, M. F. (19
Linguistics: 77
aspects (pp. 6'
Garrett. M. F. (19'
presented at tl
NY.
Jarvella, R. J. (IS
Learning and
Jordan. M. I . (198
machine. Pro1
Society (pp. 5
Kilbom. K. (1988
behavioral an
and granvruit
cholinguistik,
Kutas, M.. & Hill:
and semantic
W e l t , W. J. M.
W e l t , W. J. M.
MTT Press.
M e l t , W.J. M-,
J. (1991). Th
naming. Psyi
Â¥MartinN.. Wei:
occurrence o
of Memory a
O'Seaghdha, P . (
resentations
chonomic S(
Ristad, E. S. (19'
at the CUN'
Schricfers, H., N
lexical acce:
Memory am
Shaituck-Hufnag
in sentence
processing:
Hillsdale, f
Shattuck-Hufnag
planning: F
Production Problems
159
Garoham, A., Shillcock, R. C. Brown, G. D. A., Mill, A. I. D.. & Cutler, A. (1982).
Slips of the tongue in the London-Lund corpus of spontaneous conversation. In A.
Cutler (Ed.), Slips of the tongue and language production (pp. 25 1-263). Berlin:
Mouton.
Garrett, M. F. (1975). The analysis of sentence production. In G. H. Bower (Ed.), The
psychology of learning and motivation (pp. 133-177). New York: Academic Press.
Garrett. M. F. (1980). Levels of processing in sentence production. In B. Butterworth
(Ed.), Language production (pp. 177-220). London: Academic Press.
Garrett. M. F. (1988). Processes in language production. In F. J. Newmeyer (Ed.),
Linguistics: The Cambridge survey, HI: Language: Psychological and biological
aspects (pp. 69-96). Cambridge, England: Cambridge University Press.
Garrett, M. F. (1990. March). Processing vocabularies in language production. Paper
presented at the CUNY Conference on Human Sentence Processing, New York,
NY.
Jarvella, R. J. (1971). Syntactic processing of connected speech. ~ournaiof Verbal..
Learning and Verbal Behavior, 10, 409416.
Jordan, M. I. (1986). Attractor dynamics and parallelism in a connectionist sequential
machine. Proceedings of the Eighth Annual Conference of the Cognitive Science
Society (pp. 531-546). Hillsdale, NJ: Erlbaum.
Kilborn, K. (1988). A note on the on-line nature of discourse processing: Comparing
behavioral and ekctrvphysiological m e a s w in I T ~ o ~ ~ I ofor
M ~ semantic anomalies
and grammatical errors. Unpublished manuscript, Max-Planck-Institut fur Psycholinguistik, Nijmegen, The Netherlands.
Kutas, M., & Hillyard, S. A. (1983). Event-related brain potentials to grammatical errors
and semantic anomalies. Memory & Cognition, 11, 539-550.
Levell. W. J. M. (1983). Monitoring and self-repair in speech. cognition, 14, 41-104.
Lcvelt, W. J. M. (1989). Speaking: From intention to articulation. Cambridge, M A : \
MIT Press.
b e l t , W. J. M.. Schriefere, H.. Vorberg. D.. Meyer, A. S., Pechrnann, T., & Havinga,
J. (1991). The time course of lexical access in speech production: A study of picture
naming. Psychological Review, 98, 122-142.
Martin, N., Weisberg, R. W., & Saffran, E. M. (1989). Variables influencing the
occurrence of naming errors: Implications for models of lexical retrieval. Journal
of Memory and Language, 28, 462485.
O'Seaghdha, P. G.. Dell, G. S.. & Peterson. R. R. (1988. November). Indexing representations in language production. Paper presented at the meeting of the Pv chonomic Society, Chicago, IL.
Rislad, E. S. (1990, March). Obstacles to efficient languageprocessing. Paper presented
at the CUNY Conference on Human Sentence Processing, New York. NYSchriefers, H., Meyer, A. S., & b e l t , W. J. M. (1990). Exploring the time course of
lexical access in language production: Picture-word interference studies. Jounml of
Memory and Language, 29, 86-102.
Shattuck-Hufnagel, S. (1979). Speech errors as evidence for a serial-ordering mechanism
in sentence production. In W. E. Cooper & E. C. T. Walker (Eds.), Sentence
processing: Psychoiinguistic studies presented to Merrill Garrett (pp. 295-342).
Hillsdaic. NJ: Erlbaum.
Shat~uck-Hufnagel.S. (1987). The role of word-onset consonants in speech production
planning: New evidence from speech error patterns. In E. Keller & M. Gopnik
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baumSlemberger, J. P. (1985). An interactive activation model of language production. In A.
Ellis (Ed.), Progress in the psychology of language (pp. 143-186). London: Erlbaum.
Stemberger, J. P. (1990). wordshape errors in language production. Cognition. 35, 123-
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157.
Sternberg, S., Knoll, R. L., Monsell, S., & Wright, C. E. (1988). Motor programs and
hierarchical organization in the control of rapid speech. Phonetics, 45, 175-197.
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