bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Disservice to the Ideas of Theory, Research, and Expertise
Authors: Swanson Richard A. 
Published: July 2003

A student casually states that he is going to the library to do some research when he is simply going there to read and retrieve a few documents. Finding and reading written materials by themselves are not research. A businessperson claims to be doing action research when in fact she is simply solving a difficult workplace problem. Solving a problem by itself is not research. A professor directs a brainstorming session and then helps the group to classify its ideas as well as choose the best option. Generating new ideas or hypotheses is not by itself research. The successful executive or sports coach writes a book on leadership to expound on his personal theory of leadership. Personal theories by themselves do not qualify as sound theory. A mortgage banker who can efficiently and accurately complete mortgage transactions is deemed by his colleagues as an expert. Because a person can do a job well does not constitute expertise.
On the different uses of linguistic abstractness: from LIB to LEB and beyond
Authors: Fiedler Klaus , Bluemke Matthias , Friese Malte , Hofmann Wilhelm 
Published: July 2003

AbstractLinguistic abstractness has been shown to mediate persuasive and attributional effects of communication. The linguistic intergroup bias (LIB) refers to the tendency to describe positive ingroup and negative outgroup behaviors more abstractly than negative ingroup and positive outgroup behavior. Recently, the LIB was shown to reflect to a large extent a linguistic expectancy bias (LEB). Abstract language need not have an ingroup‐serving function, but may be used to communicate expected information in a concise and condensed manner. The present research shows that the reverse may also be true. When the interaction goal is not merely to convey information that is shared anyway because it is typical of the communication target but to transmit unshared information (known to the communicator but new to the recipient), then it may be necessary to express (explain, teach, interpret) unexpected ideas or deviant attitudes in abstract, interpretive terms. The joint operation of both principles was demonstrated within the same experimental task. In communications about East Germans, more abstract predicates were used in typically East German domains (LEB). However, more abstract terms were also used when messages deviated from the recipient's prior attitude. A conceptual framework is proposed to integrate these findings. Copyright © 2003 John Wiley & Sons, Ltd.
Acquisition of dispositional attributions: effects of sample size and covariation
Authors: Van Overwalle Frank 
Published: July 2003

AbstractTwo experiments examined whether dispositional attributions are sensitive to the sample size of the evidence indicating a given level of covariation between person and behavior. Participants were given high or low levels of covariation (i.e. consensus and distinctiveness), and the acquisition of dispositional attributions was monitored by requesting dispositional trait ratings at fixed intervals. The results showed that dispositional attributions were sensitive to sample size, and increased given more evidence on high person‐behavior covariation while they decreased given more evidence on low person‐behavior covariation. Additional analyses suggested that in making dispositional inferences (e.g. about the actor), there was a slight preference for agreement information (e.g. low distinctiveness) over difference information (e.g. low consensus). The effects of sample size are inconsistent with current statistical or probabilistic models of covariation, but are in line with connectionist networks using an error‐correcting learning algorithm. Copyright © 2003 John Wiley & Sons, Ltd.
Perspective taking and prejudice reduction: the mediational role of empathy arousal and situational attributions
Authors: Vescio Theresa K. , Sechrist Gretchen B. , Paolucci Matthew P. 
Published: July 2003

AbstractThis research was designed to examine whether perspective taking promotes improved intergroup attitudes regardless of the extent that stereotypic perceptions of outgroups are endorsed, as well as examining the mechanisms (attributional or empathy related) by which perspective taking motivates improved intergroup attitudes. Participants were presented with an interview segment where an African American interviewee discussed the difficulties experienced as a result of his membership in a negatively stereotyped group. Materials were presented in a 2 (perspective taking: other focused or objective focused) × 2 (target stereotypicality: confirming or disconfirming) between participants design. Findings revealed that the manipulation of target stereotypicality influenced subsequent stereotype endorsement; those exposed to a stereotype confirming target later endorsed more stereotypic perceptions of African Americans than did those exposed to a stereotype disconfirming target. However, perspective taking promoted improved intergroup attitudes irrespective of stereotypicality; those encouraged to adopt the perspective of the target later reported more favourable intergroup attitudes than did those who remained detached and objective listeners. Whereas empathy partially mediated the relation between perspective taking and intergroup attitudes, situational attributions were a stronger and more reliable mediator. Copyright © 2003 John Wiley & Sons, Ltd.
Beyond attitudinal ambivalence: effects of belief homogeneity on attitude‐intention‐behaviour relations
Authors: Armitage Christopher J. 
Published: July 2003

AbstractAttitudinal ambivalence extends the traditional unidimensional conceptualization of attitude by acknowledging that people can simultaneously evaluate attitude objects as positive and negative. The present paper argues that this bidimensional view of attitudes may be extended further to take account of multidimensional influences on attitudes using measures of belief homogeneity. Study 1 (n = 155) showed that attitudes based on homogeneous belief‐sets were significantly more predictive of subsequent behaviour (β = 0.47, p<0.01) than were attitudes based on heterogeneous belief‐sets (β = 0.08, ns). Study 2 (n = 136) manipulated belief homogeneity and found that when beliefs were made heterogeneous, attitudes based on heterogeneous belief‐sets were significantly less predictive of behavioural intentions (β = 0.46, p < 0.01) than attitudes based on homogeneous belief‐sets (β = 0.84, p < 0.01). Implications for research on attitudinal ambivalence and attribute importance are discussed. Copyright © 2003 John Wiley & Sons, Ltd.
In search of leading indicators of economic activity in Germany
Authors: Bandholz Harm , Funke Michael 
Published: July 2003

AbstractIn this paper we present two new composite leading indicators of economic activity in Germany estimated using a dynamic factor model with and without regime switching. The obtained optimal inferences of business cycle turning points indicate that the two‐state regime switching procedure leads to a successful representation of the sample data and provides an appropriate tool for forecasting business conditions. Copyright © 2003 John Wiley & Sons, Ltd.
A neural network versus Black–Scholes: a comparison of pricing and hedging performances
Authors: Amilon Henrik 
Published: July 2003

AbstractAn Erratum has been published for this article in Journal of Forecasting 22(6‐7) 2003, 551
The Black–Scholes formula is a well‐known model for pricing and hedging derivative securities. It relies, however, on several highly questionable assumptions. This paper examines whether a neural network (MLP) can be used to find a call option pricing formula better corresponding to market prices and the properties of the underlying asset than the Black–Scholes formula. The neural network method is applied to the out‐of‐sample pricing and delta‐hedging of daily Swedish stock index call options from 1997 to 1999. The relevance of a hedge‐analysis is stressed further in this paper. As benchmarks, the Black–Scholes model with historical and implied volatility estimates are used. Comparisons reveal that the neural network models outperform the benchmarks both in pricing and hedging performances. A moving block bootstrap is used to test the statistical significance of the results. Although the neural networks are superior, the results are sometimes insignificant at the 5% level. Copyright © 2003 John Wiley & Sons, Ltd.
Validation studies of drug exposures in pregnant women
Authors: Czeizel A. E. , Petik D. , Vargha P. 
Published: July 2003

AbstractThe aim of these studies was to check the quality of data collection concerning drug use during pregnancy in the Hungarian Case–Control Surveillance of Congenital Abnormalities from four different aspects. (a) The parents of non‐respondent cases were visited at home to collect data, but the Ethics Committee did not allow collection of comparable data from non‐respondent control women. Thus only 200 selected non‐respondent controls were visited at home and questioned about drug use as part of a validation study. There was no difference in the distribution and occurrence of frequently used drugs between the respondent and non‐respondent control groups. (b) Data collection was compared between the usual method of the Case–Control Surveillance and personal interview in cases with congenital limb deficiencies. In general, the two methods produced similar results with respect to drug use, but the personal interview revealed a higher use of unintended contraceptive pills while the use of antenatal care logbooks in the Case–Control Surveillance showed a higher use of drugs to prevent threatened abortion and preterm delivery. (c) A check of source and completeness of drug exposure showed that about one‐quarter of the drugs used during pregnancy were not recorded in the Case–Control Surveillance, and the proportion of lack of recall was about 23%. A small group of women (2.4%) did not use prescribed drugs due to the suspected teratogenic risk. (d) The teratogenic labelling of drugs deters pregnant patients from the use of prescribed drugs, or at least shortens the duration of drug intake. Thus the evaluation of drug use on the basis of medically recorded prescribed drugs and/or usual recommendations produces a bias thus it is necessary to complete it with information from the patients. Copyright © 2003 John Wiley & Sons, Ltd.
Indinavir did not further increase mean triglyceride levels in HIV‐infected patients treated with nucleoside reverse transcriptase inhibitors: An analysis of three randomized clinical trials
Authors: Rojas Carlos , Coplan Paul M. , Rhodes Thomas , Robertson Michael N. , DiNubile Mark J. , Guess Harry A. 
Published: July 2003

AbstractObjectivesMetabolic abnormalities including hyperlipidemia have developed in patients infected with the human immunodeficiency virus (HIV) after treatment with protease inhibitor drugs. It is unclear whether the deleterious effects on plasma triglyceride concentrations observed in patients receiving highly active antiretroviral therapy are a class effect of protease inhibitors. Hypertriglyceridemia may constitute a risk factor for cardiovascular disease. The purpose of this retrospective analysis of HIV‐infected patients enrolled in three randomized, double‐blind trials of indinavir therapy was to determine whether indinavir use was associated with a larger increase in triglyceride levels than treatment without a protease inhibitor.MethodsUsing a mixed‐effects model, we compared average changes in nonfasting plasma triglyceride levels among randomized treatment groups for each protocol separately.ResultsThe median increase in triglyceride levels during the 1st year of antiretroviral monotherapy was less with indinavir than with either zidovudine or stavudine. The combination of indinavir and nucleoside‐analogue reverse‐transcriptase inhibitors (NRTI) resulted in smaller increments in triglyceride levels than NRTI monotherapy. Indinavir also augmented the reduction in triglyceride levels observed with combination therapy using zidovudine and lamivudine in persons with far advanced HIV‐infection. However, up to 7% of patients receiving a NRTI and indinavir experienced elevations of nonfasting triglyceride levels in excess of 750 mg/dl.ConclusionsOn average, the combination of indinavir and NRTI therapy was not associated with a greater elevation of non‐fasting triglyceride levels in HIV‐infected men with at least moderately advanced immunosuppression than treatment with NRTI drugs alone. Copyright © 2003 John Wiley & Sons, Ltd.
The Cuban experience in focusing pharmaceuticals policy to health population needs: initial results of the National Pharmacoepidemiology Network (1996–2001)
Authors: Diogène Eduard , Peña Julián Pérez , Figueras Albert , Furones Juan Antonio , Debesa Frank , Laporte Joan‐Ramon 
Published: July 2003

AbstractIn 1996, a National Pharmacoepidemiology Network was set up in Cuba in order to disseminate problem‐oriented information and develop continuing education activities on drug therapy, to perform research on drug utilisation and to promote interventions to improve drug use. It is coordinated by the Centre for the Development of Pharmacoepidemiology, which is also in charge of regulatory and administrative duties and collaborates with the National Pharmaceutical Industry. By 2001, a number of educational and information initiatives had been undertaken, particularly in primary health care, which resulted in improvement of indicators of drug use. Cuba keeps good health standards in spite of a short health budget. Copyright © 2003 John Wiley & Sons, Ltd.
Doctors' prescription behaviour regarding dosage recommendations for preparations of kava extracts
Authors: Dietlein G. , Schröder‐Bernhardi D. 
Published: July 2003

AbstractBackgroundThere are many publications on the use of kava extracts as a treatment alternative to tricyclic antidepressants and benzodiazepines, but little has been done to investigate the potential adverse effects that may be associated with prolonged or high‐dose usage.ObjectivesTo investigate the extent to which physicians comply with the recommended daily dose (RDD) of an antidepressant such as kava and the consequences of this behaviour with regard to the safety and efficacy of frequently prescribed kava extracts (Trade names: Antares™, Laitan™ and Kavasporal forte™).MethodThe analysis was carried out using the patient database MediPlus®, which provides anonymous access to a representative and valid panel of physicians and patients in Germany.ResultsPrescriptions for Antares showed that the RDD of 1 tablet per day was exceeded in 58.2% of the cases, while those for Laitan showed that the RDD of 1 capsule per day was significantly exceeded in 75.6% of the cases; a one‐off prescription was issued in 66% of the cases. As a result, the required effect diminished very quickly. Prescriptions for Kavasporal forte showed that the daily dosage of 2 capsules per day complied with the recommendations in only 49.1% of the cases; in 38.8% of the cases, the dosage dropped below the respective recommendation. As a consequence, the lower‐dosed Kavasporal forte was prescribed for longer periods than the higher‐dosed Antares and Laitan.ConclusionsIn the case of a low‐dosage recommendation, we saw a trend to over‐dose in prescribing behaviour, which increases the risk of undesirable adverse reactions. On the other hand, we saw a trend to under‐dose in the case of a higher dosage recommendation. This fact may explain the unexpected inefficacy of the therapy. These trends affected the duration of therapy, whereby a dosage lower than the RDD was prescribed for a longer period than a dosage higher than the RDD. Copyright © 2003 John Wiley & Sons, Ltd.
ROC curve analysis for biomarkers based on pooled assessments
Authors: Faraggi David , Reiser Benjamin , Schisterman Enrique F. 
Published: July 2003

AbstractInterleukin‐6 is a biomarker of inflammation which has been suggested as having potential discriminatory ability for myocardial infarction. Because of its high assaying cost it is very expensive to evaluate this marker. In order to reduce this cost we propose pooling the specimens. In this paper we examine the efficiency of ROC curve analysis, specifically the estimation of the area under the ROC curve, when dealing with pooled data. We study the effect of pooling when there are only a fixed number of individuals available for testing and pooling is carried out to save on the number of assays. Alternatively we examine how many pooled assays of size g are necessary to provide essentially the same information as N individual assays. We measure loss of information by means of the change in root mean square error of the estimate of the area under the ROC curve and study the extent of this loss via a simulation study. Copyright © 2003 John Wiley & Sons, Ltd.
Properties of internal pilots with the univariate approach to repeated measures
Authors: Coffey Christopher S. , Muller Keith E. 
Published: July 2003

AbstractUncertainty surrounding the error covariance matrix often presents the biggest barrier to achieving accurate power analysis in the ‘univariate’ approach to repeated measures analysis of variance (UNIREP). A poor choice gives either an overpowered study which wastes resources, or an underpowered study with little chance of success. Internal pilot designs were introduced to resolve such uncertainty about error variance for t‐tests. In earlier papers, we extended the use of internal pilots to any univariate linear model with fixed predictors and independent Gaussian errors. Here we further extend our exact and approximate results to UNIREP analysis. For a fixed treatment effect, the inaccuracy in a power calculation depends only on the ratio of the true variance to the value used for planning. The greater complexity of repeated measures requires generalizing misspecification of error variance to the misspecification of the eigenvalues of the error covariance. We recommend approximating the misspecification in terms of the first and second moments of the eigenvalues, for both fixed sample and internal pilot designs. We also describe an unadjusted approach for internal pilots with repeated measures. Simulations illustrate the fact that both positive and negative properties in the univariate setting extend to repeated measures analysis. In particular, internal pilots allow maintaining power or reducing expected sample size when the covariance matrix used for planning differs from the true value. However, an unadjusted approach can inflate test size, at least with small to moderate sample sizes. Hence new, adjusted methods must be developed for small samples. At this time, we caution against using an internal pilot design with repeated measures without first conducting simulations to document the amount of test size inflation possible for the conditions of interest. Copyright © 2003 John Wiley & Sons, Ltd.
Misclassification in a matched case‐control study with variable matching ratio: application to a study of c‐erbB‐2 overexpression and breast cancer
Authors: Duffy Stephen W. , Rohan Thomas E. , Kandel Rita , Prevost Teresa C. , Rice Kenneth , Myles Jonathan P. 
Published: July 2003

AbstractWe provide a simple analytic correction for risk factor misclassification in a matched case‐control study with variable numbers of controls per case. The method is an extension of existing methodology, and involves estimating the corrected proportions of controls and cases in risk factor categories within each matched set. These estimates are then used to calculate the Mantel–Haenszel odds ratio estimate corrected for misclassification. A simulation‐based interval estimate is developed. An example is given from a study of risk factors for progression of benign breast disease to breast cancer, in which the risk factor is a biological marker measured with poor sensitivity. Copyright © 2003 John Wiley & Sons, Ltd.
Last observation carry‐forward and last observation analysis
Authors: Shao Jun , Zhong Bob 
Published: July 2003

AbstractDrop‐out often occurs in clinical trials with multiple visits and drop‐out is often informative in the sense that the population of patients who dropped out is different from the population of patients who completed the study. To handle data with informative drop‐out, an intention‐to‐treat analysis, which evaluates treatment effects over the population of all randomized patients with at least one post‐treatment evaluation, is often required by the regulatory agencies. As a popular and simple intention‐to‐treat analysis, the last observation carry‐forward (LOCF) analysis of variance (ANOVA) performs a statistical test for treatment effects by treating the last observation prior to drop‐out as the observation from the last visit. Although discussions, examples and limited empirical results about the LOCF analysis can be found, its theoretical property is unclear. We find that the LOCF one‐way ANOVA test is actually asymptotically valid (that is, its asymptotic size is equal to the nominal size) in the special but important case where only two treatments are compared and the two treatment groups have the same number of patients, regardless of whether drop‐out is informative or not. In other cases, however, the asymptotic size of the LOCF test is different from the nominal size and is often too small when drop‐out is informative, which results in a loss in power of detecting treatment effects, a disadvantage to drug companies. We propose an asymptotically valid test for comparing the global means over subpopulations, where each subpopulation contains patients dropping out after a particular visit. Some simulation results are presented to study the finite sample performance of the LOCF test and our proposed test. Copyright © 2003 John Wiley & Sons, Ltd.
Modelling and analysing exchangeable binary data with random cluster sizes
Authors: Xu Jian‐Lun , Prorok Philip C. 
Published: July 2003

AbstractCorrelated binary data occur very frequently in cluster sample surveys, dependent repeated cancer screening, teratological experiments, ophthalmologic and otolaryngologic studies, and other clinical trials. The standard methods to analyse these data include the use of beta‐binomial models and generalized estimating equations with third and fourth moments specified by ‘working matrices’. However, in many applications it is reasonable to assume that the data from the same cluster are exchangeable. When all sampled clusters have equal sizes, Bowman and George introduced maximum likelihood estimates (MLEs) of the population parameters such as the marginal means, moments, and correlations of order two and higher. They also extended their approach to sampled clusters with unequal sizes. It seems that their extension has a gap. This paper points out the source of this gap and shows that estimates introduced by Bowman and George are not the MLEs of the parameters which are used to identify the joint distribution of correlated binary data. We show that the MLEs of the population parameters have no closed form in general and should be calculated by numerical methods. We apply our results and a generalized estimating equation procedure to a data set from a double‐blind randomized clinical trial comparing two antibiotics, cefaclor and amoxicillin, used for the treatment of acute otitis media. To see the performance of the MLEs with small or moderate sample sizes, several simulation studies are also conducted. Published in 2003 by John Wiley & Sons, Ltd.