2 Taxonomy is always a contentious issue because the world does not come to us in neat little packages (S. Personality has been conceptualized from a variety of theoretical perspectives, and at various levels of Each of these levels has made unique contributions to our understanding of individual differences in behavior and experience. However, the number of personality traits, and scales designed to measure them, escalated without an end in sight (Goldberg, 1971). Researchers, as well as practitioners in the field of personality assessment, were faced with a bewildering array of personality scales from which to choose, with little guidance and no overall rationale at hand. What made matters worse was that scales with the same name often measure concepts that are not the same, and scales with different names often measure concepts that are quite similar. Although diversity and scientific pluralism are useful, the systematic accumulation of findings and the communication among researchers became difficult amidst the Babel of concepts and scales. Many personality researchers had hoped that they might devise the structure that would transform the Babel into a community speaking a common language. However, such an integration was not to be achieved by any one researcher or by any one theoretical perspective. As Allport once put it, " each assessor has his own pet units and uses a pet battery of diagnostic devices " (1958, p. 258). What personality psychology needed was a descriptive model, or taxonomy, of its subject matter. One of the central goals of scientific taxonomies is the definition of overarching domains within which large numbers of specific instances can be understood in a simplified way. Thus, in personality psychology, a taxonomy would permit researchers to study specified domains of personality characteristics, rather than examining separately the thousands of particular attributes that make human beings individual and unique. Moreover, a generally accepted taxonomy would greatly facilitate the accumulation and communication of empirical findings by offering a standard vocabulary, or nomenclature. After decades of research, the field is approaching consensus on a general taxonomy of personality traits, the " Big Five " personality dimensions. These dimensions do not represent a particular theoretical perspective but were derived from analyses of the natural-language terms people use to describe themselves 3 and others. Rather than replacing all previous systems, the Big Five taxonomy serves an integrative function because it can represent the various and diverse systems of personality …

The Big Five Trait taxonomy: History, measurement, and theoretical perspectives.

This personal historical article traces the development of the Big-Five factor structure, whose growing acceptance by personality researchers has profoundly influenced the scientific study of individual differences. The roots of this taxonomy lie in the lexical hypothesis and the insights of Sir Francis Galton, the prescience of L. L. Thurstone, the legacy of Raymond B. Cattell, and the seminal analyses of Tupes and Christal. Paradoxically, the present popularity of this model owes much to its many critics, each of whom tried to replace it, but failed. In reaction, there have been a number of attempts to assimilate other models into the five-factor structure. Lately, some practical implications of the emerging consensus can be seen in such contexts as personnel selection and classification.

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The Structure of Phenotypic Personality Traits

Pedagosko i psiholosko testiranje i procjenjivanje spadaju među najvažnije doprinose znanosti o ponasanju nasem drustvu i pružaju temeljna i znacajna poboljsanja u odnosu na ranije postupke. Iako se ne može ustvrditi da su svi testovi dovoljno usavrseni niti da su sva testiranja razborita i korisna, postoji velika kolicina informacija koje ukazuju na ucinkovitost kvalitetnih instrumenata u onim situacijama u kojima je njihovo koristenje potkrijepljeno validacijskim podacima. Pravilna upotreba testova može dovesti do boljih odluka o pojedincima i programima nego sto bi to bio slucaj bez njihovog koristenja, a također i ukazati na put za siri i pravedniji pristup obrazovanju i zaposljavanju. Međutim, losa upotreba testova može dovesti do zamjetne stete nanesene ispitanicima i drugim sudionicima u procesu donosenja odluka na temelju testovnih podataka. Cilj Standarda je promoviranje kvalitetne i eticne upotrebe testova te uspostavljanje osnovice za ocjenu kvalitete postupaka testiranja. Svrha objavljivanja Standarda je uspostavljanje kriterija za evaluaciju testova, provedbe testiranja i posljedica upotrebe testova. Iako bi evaluacija prikladnosti testa ili njegove primjene trebala ovisiti prvenstveno o strucnim misljenjima, Standardi pružaju okvir koji osigurava obuhvacanje svih relevantnih pitanja. Bilo bi poželjno da svi autori, sponzori, nakladnici i korisnici profesionalnih testova usvoje Standarde te da poticu druge da ih također prihvate.

Standards for educational and psychological testing

On robust estimation of the location parameter

Measurement and control of response bias.

We focus on the identification of differential item functioning (DIF) when more than two groups of examinees are considered. We propose to consider items as elements of a multivariate space, where DIF items are outlying elements. Following this approach, the situation of multiple groups is a quite natural case. A robust statistics technique is proposed to identify DIF items as outliers in the multivariate space. For low dimensionalities, up to 2-3 groups, a simple graphical tool is derived. We illustrate our approach with a reanalysis of data from Kim, Cohen, and Park (1995) on using calculators for a mathematics test.

Identification of Differential Item Functioning in Multiple-Group Settings: A Multivariate Outlier Detection Approach.

A procedure of data gathering and data analysis is proposed in order to retrieve the implicit taxonomy of an individual psychiatric diagnostician. This implicit taxonomy may contain both simple and combined syndromes. In line with psychopathological prototype research, membership in a class of the taxonomy may be a matter of degree. The procedure provides a picture of the syndrome overlap and of the most succinct co-occurrence and if-then relationships between symptoms. In order to illustrate the approach, a case study is made of an individual psychiatrist. The resulting implicit taxonomy can be interpreted rather easily, and it proves to be closely related to results of the diagnostic process such as DSM-III diagnoses made by the diagnostician under study, as well as to important decisions to be taken by him. It is concluded that the procedure may be useful for individual feedback as well as for more general investigations into the cognitive mechanisms behind psychiatric diagnosis.

Implicit Taxonomy in Psychiatric Diagnosis: A Case Study

The models discussed in the previous chapters recognize the clustered structure of data one is confronted with most often in psychometrics (i.e., items within persons). The within-person dependencies arising from this clustering are handled through a random effect or latent variable for person p, denoted as θ p . In some cases, there are several major sources of individual differences, and they have to be accounted for by more than one random effect (see Chapter 8 on multidimensionality). Conditional on these random effects, the responses to the different items in the data set should be independent — this requirement is called conditional independence or local (stochastic) independence. However, it appears that in many applications, not all dependence between the responses can be explained by the random effects one assumed to underly the responses. In those cases, it is said that there remain some residual dependencies not accounted for by the model, a phenomenon also denoted as local item dependencies (LIDs). Situations in which residual dependencies may occur are ample. Consider for instance the case where items of a reading test can be subdivided into groups of items each sharing the same reading passage. Data from a test with reading passages may show more dependencies than can be accounted for alone by a single reading ability dimension.

Models for residual dependencies

The MIRID CML program is a program for the estimation of the parameter values of two different componential IRT models: the Rasch-MIRID and the OPLM-MIRID (Butter, 1994; Butter, De Boeck, & Verhelst, 1998). To estimate the parameters of both models, the program uses a CML approach. The model parameters can also be estimated with a MML approach that can be implemented in PROC NLMIXED of SAS Version 8. Both the MIRID CML program and the MML SAS approach are explained and compared in a simulation study. The results showed that they did about equally well in estimating the values of the item parameters but that there were some differences in the estimation of the person parameters, as could be expected from the differential assumptions regarding the distribution of the persons. The SAS MML approach is much slower than the MIRID CML program, but it is more flexible.

/pdf/estimation-of-the-mirid-a-program-and-a-sas-based-approach-2j7stjota4.pdf

Estimation of the MIRID: A program and a SAS-based approach

https://isiarticles.com/bundles/Article/pre/pdf/33307.pdf

Paul De Boeck

Papers

Identification of Differential Item Functioning in Multiple-Group Settings: A Multivariate Outlier Detection Approach.

Implicit Taxonomy in Psychiatric Diagnosis: A Case Study

Models for residual dependencies

Estimation of the MIRID: A program and a SAS-based approach

From anger to verbal aggression: Inhibition at different levels