bluuebunny/crossref_metadata_2025 huggingface dataset:
HEALTH TECHNOLOGY ASSESSMENT AND SCREENING IN THE NETHERLANDS
Authors: David Banta H. , Oortwijn Wija
Published: December 2002

Objective: To review the assessment and implementation of three screening methods: mammography for breast cancer, screening for prostate cancer, and routine use of ultrasound in pregnancy.

Methods: To review policy documents and published papers dealing with prevention and screening in the Netherlands, focusing on the three screening methods specified.

Results: The results indicate that the Netherlands has an active establishment devoted to health technology assessment (HTA). The Netherlands government has also made prevention a high priority in the health services system. Within prevention policy, HTA is given an important place. The general policy is that prevention programs should meet high standards of effectiveness and efficiency, as well as ethical, legal, and social acceptability. In addition, the Netherlands may be unique in the world in having a specific law requiring that proposals for population screening must be carefully assessed before they are implemented.

Conclusions: The three cases examined in this paper have all been assessed, and the conclusions are similar to those presented in the synthesis published in this issue (33). In the case of mammography, the assessment was followed by a rational implementation of a national screening program for breast cancer. In the other two cases, however, despite negative conclusions from assessment, the tests are frequently carried out, especially in what has been termed opportunistic screening. Prostate cancer screening seems to be spreading rapidly. Use of ultrasound in pregnancy is frequent, not necessarily for medical reasons but because parents wish to have a picture of their fetus. The conclusion is that HTA is well established in the Netherlands, as illustrated in these three cases, and policy is based on the assessments done. However, practice is not in accord with the assessment in the cases of prostate cancer and routine ultrasound. Policies to deal effectively with opportunistic screening are difficult to imagine.
HEALTH TECHNOLOGY ASSESSMENT AND SCREENING IN SWEDEN
Authors: Jonsson Egon , David Banta H. , Scherstén Tore
Published: December 2002

Objectives: To describe health technology assessment (HTA) and policies concerning three screening procedures in Sweden.

Methods: The main source of information was reports from the Swedish Council for Technology Assessment in Health Care (SBU) and other governmental reports, supplemented by the professional literature.

Results: Prevention is emphasized in the healthcare services of Sweden. Specifically, screening is encouraged and supported when it is deemed beneficial. Sweden has a strong orientation toward evidence-based health care and HTA. Since its inauguration in 1987, SBU has fostered the use of HTA in making policy and clinical decisions in Sweden. Government policy in Sweden is to encourage services that are beneficial and cost-effective and discourages services that are not. Screening is no exception to this general rule. The three cases examined in this paper—mammography screening, PSA screening, and routine ultrasound screening in pregnancy—have all been formally assessed in Sweden. Assessments have been an integral part of policy making concerning these and other preventive measures. Mammography screening has been widely implemented. However, as in other countries, screening is often carried out in an opportunistic fashion, so that PSA screening, in particular, is carried out more in Sweden than can be justified by the evidence.

Conclusions: Mammography screening is promoted and is completely available to the target group. PSA screening is discouraged, but not with complete success. Ultrasound in pregnancy is widely used, not because of good evidence of impact on mortality and morbidity among newborns, but because it increases the detection rate of congenitally malformed fetuses and because of evidence of positive effects on the management and planning of deliveries, as well as because of psychological and ethical implications of the technology. HTA is an important part of health policy making in Sweden.
HEALTH TECHNOLOGY ASSESSMENT OF THREE SCREENING METHODS IN SWITZERLAND
Authors: Faisst Karin , Schilling Julian , Koch Pedro
Published: December 2002

Objective: To describe the level of health technology assessments for three screening methods in Switzerland.

Methods: Analysis of documents and expert opinions on mammography screening, ultrasound examinations during normal pregnancy, and screening for prostate-specific antigen (PSA) with a focus on services provided, recommendations, formal regulations, national papers, projects, and formal assessments.

Results: Preventive services are explicitly recommended by the Swiss federal law on health insurance. Two routine ultrasound examinations during normal pregnancy as well as PSA analysis for men over 40 years of age on medical indication are covered by basic health insurance. Mammography screening every 2 years has been covered since 1997 for women over 50 years. A systematic screening program for mammography exists in the western part of Switzerland, and a nationwide program is planned. However, a national program may not come into being until a quality assurance program for evaluation is established, and a nationwide fee for reimbursement—to include all costs of such a program—is accepted by providers and insurers.

Conclusion: According to the Swiss health insurance law, the effectiveness of mammography screening and ultrasound examinations during normal pregnancy have to be proven. Systematic evaluation of these screening methods is in preparation. PSA is not part of current evaluation. It can be concluded that health technology assessment in Switzerland is now required by law for several medical services. However, limited financial and personnel resources as well as the lack of disease registers may hamper progress in the near future.
EVIDENCE-BASED SCREENING IN THE UNITED KINGDOM
Authors: Gray J. A. Muir
Published: December 2002

Objective: To review the assessment of screening in the United Kingdom, focusing on three methods: mammography for breast cancer, screening for prostate cancer, and routine use of ultrasound in pregnancy.

Method: To review policy documents and published papers dealing with prevention and screening in the United Kingdom.

Results: Indicate that the United Kingdom has an active policy concerning the assessment of screening methods. Generally speaking, this assessment policy is part of the national program for health technology assessment (HTA). The government has given HTA an important place within health care in the United Kingdom, and prevention and screening is no exception to this general rule. The assessment of screening is now implemented through the National Screening Committee, established in 1997. The three issues reviewed in this paper have all been assessed within the context of the Department of Health. In the case of mammography, the assessment was done more than 10 years ago and was followed by a rational implementation of a national screening program for breast cancer. In the case of prostate cancer screening, two systematic reviews have concluded that screening should not be carried out. In general, this recommendation has been accepted in the United Kingdom. Use of ultrasound in pregnancy has been assessed by the National Screening Committee. This complex technology is difficult to assess, and the screening procedure is deeply embedded in clinical practice in the United Kingdom, so assessment has not had much impact on the frequency of screening.

Conclusion: HTA and the assessment of screening are well established in the United Kingdom. Policy is generally based on the assessments done, and practice generally follows the results of assessment. Assessment of screening is expected to become increasingly important in the United Kingdom during the next years.
HEALTH POLICY, HEALTH TECHNOLOGY ASSESSMENT, AND SCREENING IN EUROPE
Authors: Banta H. David , Oortwijn Wija , Cranovsky Richard
Published: December 2002

Objective: To present a summary of the papers in this volume, illustrating the links between health technology assessment (HTA), health policies and specifically policies toward prevention and screening, and implementation of screening tests in the case of three screening methods: mammography screening for breast cancer, screening for prostate cancer, and routine use of ultrasound in pregnancy.

Method: To commission papers from eight European countries based on a set of questions to be answered, as well as a paper synthesizing the scientific literature on the three screening procedures.

Results: Indicate that few of the countries examined have developed effective links between HTA, health policy, and implementation related to screening procedures. Only Sweden and the Netherlands appear to have developed such links. In the other countries, HTA has a limited role in determining health policy. It also seems to be uncommon for countries to have a specific prevention strategy.

Conclusion: The major conclusion is that countries of Europe need to develop HTA as part of prevention policies.
SINGLE-MARKET REGULATION AND INNOVATION IN EUROPE'S MEDICAL DEVICES INDUSTRY
Authors: Steg Horst , Thumm Nikolaus
Published: December 2002

In this article we analyze the influence of the legal regulatory framework in Europe, established by the two directives on medical devices and active implantable devices, on the performance of innovation in a single European market. First, we describe in general the possible influence of a single European market on innovation and the institutional features of the particular harmonization approach (“New Approach”) we are looking at here. The empirical results presented derive from a survey investigation involving 150 firms that we defined as best innovators in the European medical devices industry from a pre-survey. The results confirm that the total impact of the New Approach regulation on firms' innovation in the long term is positive. However, it also becomes clear that the impact of regulation on innovation is limited if the factors are looked at individually and that there is a clear difference regarding short-term effects. To improve the regulatory framework, several policy actions are recommended.
LETTER TO THE EDITORS
Authors: Ament André
Published: December 2002

Last year in the summer issue of this journal, Khandker et al. (3) published the results of an interesting modeling study following the cost-effectiveness of various strategies for detecting cases of colon cancer. In addition to the baseline alternative, the authors investigated eight different screening strategies and calculated the incremental cost-effectiveness of these eight strategies. Table 1 contains the results of their study in terms of cost and effectiveness as well as incremental cost-effectiveness (see Table 3, Khandler et al.).
EFFICIENT IV ESTIMATION FOR AUTOREGRESSIVE MODELS WITH
CONDITIONAL HETEROSKEDASTICITY
Authors: Kuersteiner Guido M.
Published: December 2002

This paper analyzes autoregressive time series models where
the errors are assumed to be martingale difference sequences
that satisfy an additional symmetry condition on their fourth-order
moments. Under these conditions quasi maximum likelihood estimators
of the autoregressive parameters are no longer efficient in
the generalized method of moments (GMM) sense. The main result
of the paper is the construction of efficient semiparametric
instrumental variables estimators for the autoregressive
parameters. The optimal instruments are linear functions of
the innovation sequence.

It is shown that a frequency domain approximation of the optimal
instruments leads to an estimator that only depends on the data
periodogram and an unknown linear filter. Semiparametric methods
to estimate the optimal filter are proposed.

The procedure is equivalent to GMM estimators where lagged
observations are used as instruments. As a result of the additional
symmetry assumption on the fourth moments the number of instruments
is allowed to grow at the same rate as the sample. No lag
truncation parameters are needed to implement the estimator,
which makes it particularly appealing from an applied point
of view.
PREDICTION AND SIGNAL EXTRACTION OF STRONGLY DEPENDENT PROCESSES
IN THE FREQUENCY DOMAIN
Authors: Hidalgo J. , Yajima Y.
Published: December 2002

We frequently observe that one of the aims of time series analysts
is to predict future values of the data. For weakly dependent
data, when the model is known up to a finite set of parameters,
its statistical properties are well documented and exhaustively
examined. However, if the model was misspecified, the predictors
would no longer be correct. Motivated by this observation and
because of the interest in obtaining adequate and reliable
predictors, Bhansali (1974, Journal of the Royal Statistical
Society, Series B 36, 61–73) examined the properties
of a nonparametric predictor based on the canonical factorization
of the spectral density function given in Whittle (1963,
Prediction and Regulation by Linear Least Squares)
and known as FLES.

However, the preceding work does not cover the so-called strongly
dependent data. Because of the interest in this type of processes,
one of our objectives in this paper is to examine the properties
of the FLES for these processes. In addition, we illustrate
how the FLES can be adapted to recover the signal of a strongly
dependent process, showing its consistency. The proposed method
is semiparametric in the sense that, in contrast to other methods,
we do not need to assume any particular model for the noise
except that it is weakly dependent.
SEMIPARAMETRIC ESTIMATION OF PARTIALLY LINEAR MODELS FOR
DEPENDENT DATA WITH GENERATED REGRESSORS
Authors: Li Qi , Wooldridge Jeffrey M.
Published: December 2002

In this paper we consider the problem of estimating a
semiparametric partially linear model for dependent data with
generated regressors. This type of model comes naturally from
various econometric models such as a semiparametric rational
expectation model when the surprise term enters the model
nonparametrically, or a semiparametric type-3 Tobit model when
the error distributions are of unknown forms, or a semiparametric
error correction model. Using the nonparametric kernel method and
under primitive conditions, we show that the [square root]n-consistent
estimation results of the finite-dimensional parameter in a partially
linear model can be generalized to the case of generated regressors
with weakly dependent data. The regularity conditions we use
are quite weak, and they are similar to those used in Robinson
(1988, Econometrica 56, 931–954) for independent
and observed data.
INSTRUMENTAL VARIABLE INTERPRETATION OF COINTEGRATION WITH
INFERENCE RESULTS FOR FRACTIONAL COINTEGRATION
Authors: Marmol Francesc , Escribano Alvaro , Aparicio Felipe M.
Published: December 2002

In this paper we propose an alternative characterization of
the central notion of cointegration, exploiting the relationship
between the autocovariance and the cross-covariance functions
of the series. This characterization leads us to propose a new
estimator of the cointegrating parameter based on the instrumental
variables (IV) methodology. The instrument is a delayed regressor
obtained from the conditional bivariate system of nonstationary
fractionally integrated processes with a weakly stationary error
correction term. We prove the consistency of this estimator
and derive its limiting distribution. We also show that, in
the I(1) case, with a semiparametric correction simpler
than the one required for the fully modified ordinary least squares
(FM-OLS), our fully modified instrumental variables (FM-IV) estimator
is median-unbiased, a mixture of normals, and asymptotically efficient.
As a consequence, standard inference can be conducted with this new
FM-IV estimator of the cointegrating parameter. We show by the use of
Monte Carlo simulations that the small sample gains with the new IV
estimator over OLS are remarkable.
ASYMPTOTIC INFERENCE ON THE MOVING AVERAGE IMPACT MATRIX
IN COINTEGRATED I (2) VAR SYSTEMS
Authors: Paruolo Paolo
Published: December 2002

This paper provides asymptotic standard errors for the moving
average (MA) impact matrix for the second differences of a vector
autoregressive (VAR) process integrated of order 2, I(2).
Standard errors of the row space of the MA impact matrix are also
provided; bases of this row space define the common I(2)
trends linear combinations. These standard errors are then used to
formulate Wald-type tests. The MA impact matrix is shown to be linked
to impact factors that measure the total effect of disequilibrium
errors on the growth rate of the system. Most of the relevant
limit distributions are Gaussian, and we report artificial
regressions that can be used to calculate the estimators of
the asymptotic variances. The use of the techniques proposed
in the paper is illustrated on UK money data.
NECESSARY AND SUFFICIENT MOMENT CONDITIONS FOR THE
GARCH(r,s) AND ASYMMETRIC POWER
GARCH(r,s) MODELS
Authors: Ling Shiqing , McAleer Michael
Published: December 2002

Although econometricians have been using Bollerslev's
(1986, Journal of Econometrics 31, 307–327)
GARCH(r, s) model for over a decade, the higher
order moment structure of the model remains unresolved. The sufficient
condition for the existence of the higher order moments of the
GARCH(r, s) model was given by Ling (1999a, Journal
of Applied Probability 36, 688–705). This paper shows that
Ling's condition is also necessary. As an extension, the necessary
and sufficient moment conditions are established for Ding, Granger, and
Engle's (1993, Journal of Empirical Finance, 1,
83–106) asymmetric power GARCH(r, s) model.
TESTING FOR ZERO AUTOCORRELATION IN THE PRESENCE OF STATISTICAL
DEPENDENCE
Authors: Lobato I.N. , Nankervis John C. , Savin N.E.
Published: December 2002

The problem addressed in this paper is to test the null hypothesis
that a time series process is uncorrelated up to lag K
in the presence of statistical dependence. We propose an extension
of the Box–Pierce Q-test that is asymptotically
distributed as chi-square when the null is true for a very general
class of dependent processes that includes non-martingale
difference sequences. The test is based on a consistent estimator
of the asymptotic covariance matrix of the sample autocorrelations
under the null. The finite sample performance of this extension
is investigated in a Monte Carlo study.
STRUCTURAL CHANGES AND SEEMINGLY UNIDENTIFIED STRUCTURAL EQUATIONS
Authors: Choi In
Published: December 2002

This paper introduces structural equations that do not satisfy
the rank and/or order condition(s) for identification but still
are identifiable. These equations are called seemingly unidentified
structural equations. The key to the identifiability of these
equations is that the right-hand-side endogenous variables undergo
structural changes with respect to the exogenous and/or
predetermined variables. To estimate the seemingly unidentified
structural equations, this paper uses the classical minimum
distance (MD) estimator and the principal components instrumental
variables (PCIV) estimator. The PCIV estimator is different
from conventional IV estimators for structural equations in
that nonlinear functions of exogenous and/or predetermined
variables are used as instruments. Simulation results comparing
the estimator efficiency of the MD and PCIV estimators are reported
in this paper. The results indicate that the MD and PCIV estimators
are complementary to each other. The estimation methods proposed
in this paper are applied to the Japanese export and GDP data
to study the effect of export growth rate on that of GDP.
TWO-STEP GMM ESTIMATION OF THE ERRORS-IN-VARIABLES MODEL
USING HIGH-ORDER MOMENTS
Authors: Erickson Timothy , Whited Toni M.
Published: December 2002

We consider a multiple mismeasured regressor errors-in-variables
model where the measurement and equation errors are independent
and have moments of every order but otherwise are arbitrarily
distributed. We present parsimonious two-step generalized method
of moments (GMM) estimators that exploit overidentifying
information contained in the high-order moments of residuals
obtained by “partialling out” perfectly measured
regressors. Using high-order moments requires that the GMM
covariance matrices be adjusted to account for the use of estimated
residuals instead of true residuals defined by population
projections. This adjustment is also needed to determine the
optimal GMM estimator. The estimators perform well in Monte
Carlo simulations and in some cases minimize mean absolute error
by using moments up to seventh order. We also determine the
distributions for functions that depend on both a GMM estimate
and a statistic not jointly estimated with the GMM estimate.
A NOTE ON LEAST ABSOLUTE DEVIATION ESTIMATION OF A THRESHOLD MODEL
Authors: Caner Mehmet
Published: December 2002

This paper develops the limit law for the least absolute deviation
estimator of the threshold parameter in linear regression. In this
respect, we extend the literature of threshold models. The existing
literature considers only the least squares estimation of the threshold
parameter (see Chan, 1993, Annals of Statistics 21, 520–533;
Hansen, 2000, Econometrica 68, 575–605). This result is
useful because in the case of heavy-tailed errors there is an efficiency
loss resulting from the use of least squares. Also, for the first time in
the literature, we derive the limit law for the likelihood ratio test for
the threshold parameter using the least absolute deviation technique.
COMMENTS ON THE PAPER BY MINXIAN YANG: “SOME PROPERTIES
OF VECTOR AUTOREGRESSIVE PROCESSES WITH MARKOV-SWITCHING
COEFFICIENTS”
Authors: Francq Christian , Zakoïan Jean-Michel
Published: December 2002

This paper discusses the stationarity conditions proposed by
M. Yang (2000, Econometric Theory 16, 23–43),
in the framework of Markov-switching first-order autoregressions.
A weaker second-order stationarity assumption is proposed.
ACQUISITION OF THE ARTICLE THEBY NONNATIVE SPEAKERS OF
ENGLISH
Authors: Liu Dilin , Gleason Johanna L.
Published: December 2002

Linguistic analyses suggest that the nongeneric use of the English definite article the falls into four major categories: cultural, situation, structural, and textual. This study aims to determine whether these uses present different levels of difficulty for ESL students and whether they are acquired at the same time. The instrument consisted of 91 sentences containing 60 deleted obligatory uses of the (15 per category) and, as control items, 40 zero articles (10 per category) where the is not allowed. The participants (41 low-, 49
intermediate-, and 38 advanced-level students) were instructed to read the sentences and insert the wherever they deemed necessary. Statistical analyses of the participants'
performance indicate the following: (a) The four nongeneric uses pose different levels of
difficulty, which suggests that ESL acquisition of the is use dependent and follows a
natural order; (b) The participants' performance on the suppliance of the in
obligatory contexts for all four uses improved significantly with proficiency level, whereas the
overuse of the followed a different pattern: an initial worsening followed by an
improvement as the subjects' proficiency level increased. Pedagogical implications,
including instructional sequence and strategies for the various uses of the, are
discussed.
THE INCIDENTAL ACQUISITION OF SPANISH
Authors: Lee James F.
Published: December 2002

The present study examines the processing of Spanish future tense morphology incidentally
while reading in a second language. Previous L1 and L2 reading research has demonstrated that
readers can acquire new vocabulary as a result of reading, but can they also acquire formal
properties of the second language grammatical system? The participants in the present study had
no previous knowledge of future tense morphology such that, as they read the passage used in the
study, they encountered the target form for the first time, which is an accented á on the end of an infinitive—for example, dependerá “he, she, or it will depend.” Several variables were manipulated: (a) the frequency with which the target form appeared in the input passages (6, 10, or 16 exposures); (b) the
learner-readers' orientation to the task (neutral, meaning oriented, or form oriented); and
(c) cues to meaning (the presence or absence of future-oriented adverbials). The effects of these
variables were measured on both comprehension and input processing immediately after reading,
2 weeks later, and 1 month later. Comprehension was measured with a free-written recall and a
multiple-choice comprehension test. Input processing was measured with a multiple-choice form
recognition test and a modified cloze-form production test. The results indicate that all three
variables have some effect on comprehension and input processing.
NEGOTIATION AND ORAL ACQUISITION OF L2 VOCABULARY
Authors: de la Fuente María José
Published: December 2002

This experimental study investigates the differential effects of three conditions (nonnegotiated
premodified input, negotiation without “pushed output” [Swain, 1985],
and negotiation plus pushed output) on L2 learners' vocabulary comprehension and
acquisition (receptive and productive). Analyses of variance performed on the data indicated that:
(a) negotiated interaction had a positive effect on the comprehension of L2 words; (b) only
negotiated interaction that incorporated pushed output appeared to have promoted both receptive
and productive acquisition of words as well as an increase in productive word retention; and (c)
negotiated interaction plus output did not promote receptive acquisition more than negotiation
without output, but it was more effective in promoting productive acquisition. The findings of this
study provide empirical evidence for the important role of negotiation in facilitating the
comprehension and acquisition of L2 vocabulary, which suggests that output plays a key role
within the negotiation process for productive lexical acquisition.
MODELS, ATTENTION, AND AWARENESS IN SLA
Authors: Leow Ronald P.
Published: December 2002

Simard and Wong (2001) raise serious concerns about the theoretical and empirical (Leow,
1998b) aspects of Tomlin and Villa's (1994) model, which postulates a fine-grained analysis
of attention for SLA and the prediction that awareness at the level of detection is not crucial for
further processing of second or foreign language (L2) data. According to Simard and Wong,
Tomlin and Villa's frequently cited model has provided the “theoretical motivation
for recent studies of input enhancement and especially of textual enhancement in SLA” (p.
104), an impact that needs to be viewed with caution (p. 105). To motivate their critique of
Tomlin and Villa's model, the authors repeatedly question the validity of basing their model
on “findings from the research contexts of psychology and neuroscience” (p. 105)
and, in turn, put forward suggestions for a model of attention that they claim would better reflect
the complex nature of SLA as well as suggestions for “new” research orientations
relating to attention and awareness in SLA.
INTRODUCTION
Authors: Valdman Albert
Published: December 2002

In the past century major changes in the study of language learning, and its attendant effects on language instruction, derived from the espousal of behavioral psychology by structural linguistics of the Bloomfieldian persuasion. Did not the founder of this strand of structuralism, who collaborated in the Army language manual for the teaching of Russian under the revealing pseudonym of I. M. Lisnin, declare: “Language learning is overlearning, nothing else is of any use”? Noam Chomsky's (1959) brilliant demonstration of the reductionism of the most extreme form of behaviorism—Skinner's operant conditioning (Review of B. F. Skinner's Verbal Behavior, Language, 35, 26–58)—triggered the demise of the influence of behavioristic views of language acquisition. This demise was accompanied by that of the structural approach to second language teaching associated with such applied linguists as Robert Lado, although it must be acknowledged that the combination of these two theoretical strands did lead to significant changes in foreign language classrooms—for example, the abandonment of grammar translation and a shift of focus from written texts to speech. However, what applied linguists of that generation failed to do was to observe how actual second language learners in both naturalistic and instructed contexts process and reorganize linguistic input, how they intake it, and how they turn it into output in communicative interactions. It was not until the impact of Chomskian-inspired studies of first language acquisition and Pit Corder's (1967) seminal “The significance of learners' errors” (International Review of Applied Linguistics, 5, 161–170) that the second language learner came into focus and that the field of second language acquisition research began to flourish. In this connection, it is noteworthy that bringing to a wider international audience the proceedings of the Neuchâtel colloquia led by Corder served as a catalyst for the launching of SSLA.
FREQUENCY EFFECTS IN LANGUAGE PROCESSING
Authors: Ellis Nick C.
Published: December 2002

This article shows how language processing is intimately tuned to input frequency. Examples are given of frequency effects in the processing of phonology, phonotactics, reading, spelling, lexis, morphosyntax, formulaic language, language comprehension, grammaticality, sentence production, and syntax. The implications of these effects for the representations and developmental sequence of SLA are discussed. Usage-based theories hold that the acquisition of language is exemplar based. It is the piecemeal learning of many thousands of constructions and the frequency-biased abstraction of regularities within them. Determinants of pattern productivity include the power law of practice, cue competition and constraint satisfaction, connectionist learning, and effects of type and token frequency. The regularities of language emerge from experience as categories and prototypical patterns. The typical route of emergence of constructions is from formula, through low-scope pattern, to construction. Frequency plays a large part in explaining sociolinguistic variation and language change. Learners' sensitivity to frequency in all these domains has implications for theories of implicit and explicit learning and their interactions. The review concludes by considering the history of frequency as an explanatory concept in theoretical and applied linguistics, its 40 years of exile, and its necessary reinstatement as a bridging variable that binds the different schools of language acquisition research.
A NEW STARTING POINT?
Authors: Bardovi-Harlig Kathleen
Published: December 2002

The use of formulaic expressions by second language learners has received little attention from second language acquisition research investigating interlanguage temporal systems. Instead, this field of inquiry has emphasized the productive use of verbal morphology by employing type-token analyses. This paper considers the proposed developmental sequence of formula > low-scope pattern > construction in the emergence of future expression in a longitudinal study of 16 adult learners of English as a second language. The findings suggest that the use of formulaic expressions may be subject to individual variation and that learners may use formulaic expressions to different degrees when developing form-meaning associations even in the same grammatical subsystem, such as the tense-aspect system. The findings also suggest, however, that the practice of favoring type over token analysis as a matter of course may eliminate valuable information about the emergence and development of temporal expression.
PHONOLOGICAL EVIDENCE FOR EXEMPLAR STORAGE OF MULTIWORD SEQUENCES
Authors: Bybee Joan
Published: December 2002

Phonological evidence supports the frequency-based model proposed in the article by Nick Ellis. Phonological reduction occurs earlier and to a greater extent in high-frequency words and phrases than in low-frequency ones. A model that accounts for this effect needs both an exemplar representation to show phonetic variation and the ability to represent multiword combinations. The maintenance of alternations conditioned by word boundaries, such as French liaison, also provides evidence that multiword sequences are stored and can accrue representational strength. The reorganization of phonetic exemplars in favor of the more frequent types provides evidence for some abstraction in categories beyond the simple registration of tokens of experience.
DOES FORM-FOCUSED INSTRUCTION AFFECT THE ACQUISITION OF IMPLICIT KNOWLEDGE?
Authors: Ellis Rod
Published: December 2002

The extent to which form-focused instruction contributes to the acquisition of second language implicit knowledge is controversial. Whereas Krashen (1993) has argued that the effects of FFI on acquisition are peripheral, N. Ellis (this issue) sees FFI as facilitative and even necessary for developing implicit L2 knowledge. This article examines the role of FFI in developing implicit knowledge by reviewing 11 studies that have examined the effect of FFI on learners' free production. The review suggests that FFI can contribute to the acquisition of implicit knowledge and points to two variables that appear to influence its success—the choice of the target structure and the extent of the instruction. FFI involving extensive instruction directed at “simple” structures was more likely to succeed. However, limited instruction directed at complex structures also proved effective, provided that the target structures are readily available in noninstructional input.
NEWS FLASH—HUME STILL DEAD
Authors: Eubank Lynn , Gregg Kevin R.
Published: December 2002

Ellis refers to a wide range of data supporting the uncontroversial claim that there are frequency effects in linguistic and other behavior. He further resurrects the long-discredited claim that language acquisition consists of frequency-based abstraction of regularities from input. What he fails to do is to show how the former claim leads to the latter, or indeed to show any evidence for this claim. Ellis ignores fundamental and well-known problems—the poverty of the stimulus, cases of instantaneous acquisition, evidence for innate knowledge, evidence that even children regularly ignore perceptual input, the compositionality of concepts, and the systematicity of language—that make his frequency-based account of acquisition a nonstarter.
FREQUENCY EFFECTS AND SECOND LANGUAGE ACQUISITION
Authors: Gass Susan M. , Mackey Alison
Published: December 2002

In this response to Ellis's target article on frequency in language processing, language use, and language acquisition, we argue in favor of a role for frequency in several areas of second language acquisition, including interactional input and output and speech processing. We also discuss areas where second language acquisition appears to proceed along its own route and at its own pace regardless of the frequency of the input, as well as areas where input is infrequent but acquisition appears to be unimpeded. Our response is intended to highlight the complexity of the task of deciphering the role and importance of frequency.
INPUT-DRIVEN LANGUAGE LEARNING
Authors: Harrington Michael , Dennis Simon
Published: December 2002

Input-driven models provide an explicit and readily testable account of language learning. Although we share Ellis's view that the statistical structure of the linguistic environment is a crucial and, until recently, relatively neglected variable in language learning, we also recognize that the approach makes three assumptions about cognition and language learning that are not universally shared. The three assumptions concern (a) the language learner as an intuitive statistician, (b) the constraints on what constitute relevant surface cues, and (c) the redescription problem faced by any system that seeks to derive abstract grammatical relations from the frequency of co-occurring surface forms and functions. These are significant assumptions that must be established if input-driven models are to gain wider acceptance. We comment on these issues and briefly describe a distributed, instance-based approach that retains the key features of the input-driven account advocated by Ellis but that also addresses shortcomings of the current approaches.
MAKING SENSE OF FREQUENCY
Authors: Larsen-Freeman Diane
Published: December 2002

Nick Ellis's article is impressive for its breadth of scholarship and the cogent case made for frequency as an important factor in second language acquisition (SLA). This response begins with a brief historical sketch, which aims to contextualize the frequency factor in terms of the evolution of SLA research. Although researchers have known about a frequency effect for some time, until recently, we have lacked neurologically plausible models and technologically convenient means of measuring and testing frequency effects in input. Still, as relevant and important as a frequency factor is, it requires greater definition and qualification. For instance, L2 learners are agents of their own learning process. They do not merely record frequency; they categorize frequently occurring patterns, abstract, and generalize from them. Higher level generalizations emerge from interactions, impose top-down expectancies on future data, and, in turn, are altered by the data in a perpetually dynamic interplay. In a similar fashion, it is incumbent on SLA researchers not to be satisfied with a frequency explanation, but to interpret it—in short, to make sense of frequency.
FREQUENCY EFFECTS, NOTICING, AND CREATIVITY
Authors: Tarone Elaine
Published: December 2002

Ellis's target article suggests that language processing is based on frequency and probabilistic knowledge and that language learning is implicit. These findings are consistent with those of SLA researchers working within a variationist framework (e.g., Tarone, 1985; Bayley & Preston, 1996). This paper provides a brief overview of this research area, which has developed useful models for dealing with frequency effects in language use, and describes a psycholinguistic model of language variation currently being proposed by Preston (2000a, 2000b) that dovetails nicely with Ellis's proposals. The present commentary addresses the question “To what extent is the learner's interlanguage passively and unconsciously derived from input frequencies?” Ellis does state that factors other than frequency are also important for SLA—specifically, conscious noticing and social context. A related factor is the learner'screativity, revealed when learners' noticing leads them to view utterances not just as potential objects of analysis but as potential objects of language play. Noticing results in the selective internalization of language input in interactions with various L2 speakers, and creativity occurs in the learner's consequent production of any of a range of different voices thus internalized for the purposes of expressing social identity and of language play (Tarone 2000).
REFLECTIONS ON FREQUENCY EFFECTS IN LANGUAGE PROCESSING
Authors: Ellis Nick C.
Published: December 2002

This response addresses the following points raised in the commentaries: (a) complementary learning mechanisms, the distinction between explicit and implicit memory, and the neuroscience of “noticing”; (b) what must and what need not be noticed for learning; (c) when frequency fails to drive learning, which addresses factors such as failing to notice cues, perseveration, transfer from L1, developmental readiness, thinking too hard, pedagogical input, and practicing; (d) attention and form-focused instruction; (e) conscious and unconscious knowledge of frequency; (f) sequences of acquisition—from formula, through low-scope pattern, to construction; (g) the Fundamental Difference hypothesis; (h) the blind faith of categorical grammar; (i) Labovian variationist perspectives; (j) parsimony and theory testing; (k) universals and predispositions; and (l) wanna-contractions. It concludes by emphasizing that language acquisition is a process of dynamic emergence and that learners' language is a product of their history of usage in communicative interaction.
TOPIC CONTINUITY IN L2 ENGLISH ARTICLE USE
Authors: Jarvis Scott
Published: December 2002

Much of the research on L2 article acquisition has investigated the effects of semantic, syntactic, and discourse universals on the systematicity and variability of learners' article use. The present paper looks at systematicity from the combined perspective of two putative discourse universals related to topic continuity (e.g., Givón, 1983) that have been addressed only separately in past studies of article acquisition: the tendency to mark the distinction between topics and comments (e.g., Huebner, 1983) and the tendency to mark the distinction between new, continuous, and reintroduced NP referents (e.g., Chaudron & Parker, 1990). The present study examines how well these discourse universals account for the patterns of article use and nonuse found in narratives written by 199 Finnish-speaking and 145 Swedish-speaking adolescent learners of English. The quantitative results of the study cast some doubt on learners' sensitivity to the topic-comment distinction and also suggest that learners' tendency to mark distinctions between new, continuous, and reintroduced NP referents is influenced by the prominence of such distinctions in the L1. The quantitative results are supported by a qualitative analysis of a subset of the data that suggests numerous other elements that are needed to characterize the systematicity of individual learners' interlanguage article systems.
THE ACQUISITION OF SPANISH COPULA CHOICE AND ITS RELATIONSHIP TO LANGUAGE CHANGE
Authors: Geeslin Kimberly L.
Published: December 2002

This paper argues that crossing the boundaries between sociolinguistics and second language acquisition (SLA) is essential to both fields of study (Giacalone Ramat, 1995; Preston, 1993). Specifically, data collected in an investigation of the SLA of copula choice by 77 English-speaking learners of Spanish are examined in terms of similarities to data collected in studies of language change (Gutiérrez, 1992; Silva-Corvalán, 1994). The variables used to analyze these data, Frame of Reference and Susceptibility to Change, have been shown to be useful for examining the process of the extension of estar to new [copula + adjective] contexts from a sociolinguistic perspective. The application of these variables to SLA data allows an investigation of the mirror-image relationship predicted to exist between the process of language loss and the process of language acquisition.
ON THE RELIABILITY OF ROBUSTNESS
Authors: Bialystok Ellen
Published: December 2002

DeKeyser (2000) reports a study in which he examines three hypotheses concerning the existence of a critical period for second language acquisition. He concludes that his data support all three predictions and that the notion of a critical period is the best account of the data. However, there are problems in both his interpretation of the data and the issues raised in his discussion that undermine that conclusion. The present paper examines the evidence for the three hypotheses proposed by DeKeyser and argues that the data do not provide the necessary support for the interpretation that a critical period has influenced the results.
FOREIGN LANGUAGE AND MOTHER TONGUE. Istvan Kecskes and Tünde Papp. Mahwah, NJ: Erlbaum, 2000. Pp. xxv + 148. $39.95 cloth.
Authors: DuFon Margaret A.
Published: December 2002

Foreign language and mother tongue presents Kecskes and Papp's
cognitive-pragmatic theory of language acquisition in bilinguals and multilinguals. The unique
aspects of this theory are that it examines the positive effects of learning a second language on the
first language and that it uses multicompetence rather than monocompetence as its starting point.
The authors argue that “people who know more than one language have different
knowledge of their first language L1 than do monolingual people, and this difference can be due
to the effect of subsequent languages on the development and use of L1 skills” (p. ix).
This is essentially their first hypothesis. Their second is that the more conscious, analytic,
bottom-up approach to L2 learning can have a positive effect on the L1, which was learned using
a more subconscious, synthetic, and top-down approach. Their third hypothesis is that because of
a so-called common underlying conceptual base, new knowledge and behaviors obtained through
the L2 can enhance the real-world knowledge and linguistic skills of learners in their L1 as well as
in their L2.
TEACHING AND LEARNING ENGLISH AS A GLOBAL LANGUAGE: NATIVE
AND NON-NATIVE PERSPECTIVES. Claus Gnutzmann (Ed.).
Tüumbingen, Germany: Stauffenburg Verlag, 2000. Pp. 312. DM 96, cloth.
Authors: Berns Margie
Published: December 2002

This collection originated from a conference held in Braunschweig, Germany, in June 1998 at
which participants were invited to analyze the role of English as a global language and to develop
research perspectives for its teaching and learning. Written by nonnative as well as native speakers
of English (working in English-speaking countries where English is not a native language), the
articles provide a basis for consideration of whether “the concept of English as a global
language is assessed differently by experts depending upon whether they are native or non-native
speakers of English and if so, to what extent” (Introduction).
BILINGUALISM AND IDENTITY IN DEAF COMMUNITIES. Melanie Metzger (Ed.). Washington, DC: Gallaudet University Press, 2000. Pp. xii + 317. $55.00 cloth.
Authors: Monikowski Christine
Published: December 2002

In this volume of the Sociolinguistics in Deaf Communities series, Metzger has edited 11 diverse topics addressing two themes: the perception of Deaf people and Deaf communities, and bilingualism. Deaf people's perception of themselves and their community is explored by authors who discuss an excellent array of topics, ranging from “miracle cures” for Deaf children in Mexico to the nature of name signs in the New Zealand Deaf community; from the linguistic rights of Deaf people in the European Union to a search for the roots of the Nicaraguan Deaf community; from a semiotic analysis of Argentine Sign Language to an analysis of how a Deaf child (American Sign Language) and his hearing family (English) make sense of each other's world views.
LANGUAGE POLICY AND PEDAGOGY: ESSAYS IN HONOR OF A. RONALD
WALTON. Richard D. Lambert and Elana Shohamy (Eds.). Amsterdam: Benjamins, 2000. Pp. xii + 279. $65.00 cloth.
Authors: Reagan Timothy
Published: December 2002

Language policy and pedagogy, as its subtitle suggests, is dedicated to A. Ronald
Walton, who died quite young in 1996. Walton had served as the deputy director of the National
Foreign Language Center (NFLC) in Washington, D.C., since its founding in 1986, and the
contributors to this volume all have had direct or indirect connections to the NFLC. Further, the
essays in this volume are all related to issues and areas that were of concern to Walton during the
course of his career. All of that having been said, this work is considerably more than a typical Festschrift; it is in fact a timely and important contribution to the growing literature
dealing with both language policy and planning studies and contemporary issues in U.S. foreign
language education policy and practice.
YOUNG BILINGUAL LEARNERS IN NURSERY SCHOOL. Linda
Thompson. Clevedon, UK: Multilingual Matters, 1999. Pp. viii + 230. $79.00 cloth, $39.95
paper.
Authors: Maez Lento F.
Published: December 2002

This book is a ten-chapter ethnolinguistic study of the language and social behavior of a
group of 3-year-old third-generation British children schooled in the northeast of England. Their
families are settled migrants who speak languages other than English at home and in their
community. The study uses audiotaped recordings of the children's language, together with
thick contextual description, to provide insights into ways in which young children learn to be
communicatively competent in their new environment.