<?xml version="1.0" encoding="ISO-8859-1"?><article xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<front>
<journal-meta>
<journal-id>0120-1751</journal-id>
<journal-title><![CDATA[Revista Colombiana de Estadística]]></journal-title>
<abbrev-journal-title><![CDATA[Rev.Colomb.Estad.]]></abbrev-journal-title>
<issn>0120-1751</issn>
<publisher>
<publisher-name><![CDATA[Departamento de Estadística - Universidad Nacional de Colombia.]]></publisher-name>
</publisher>
</journal-meta>
<article-meta>
<article-id>S0120-17512010000100008</article-id>
<title-group>
<article-title xml:lang="en"><![CDATA[Synthesizing the Ability in Multidimensional Item Response Theory Models]]></article-title>
<article-title xml:lang="es"><![CDATA[Habilidad sintética en modelos multidimensionales de teoría de respuesta al ítem]]></article-title>
</title-group>
<contrib-group>
<contrib contrib-type="author">
<name>
<surname><![CDATA[MONTENEGRO DÍAZ]]></surname>
<given-names><![CDATA[ÁLVARO MAURICIO]]></given-names>
</name>
<xref ref-type="aff" rid="A01"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[CEPEDA]]></surname>
<given-names><![CDATA[EDILBERTO]]></given-names>
</name>
<xref ref-type="aff" rid="A02"/>
</contrib>
</contrib-group>
<aff id="A01">
<institution><![CDATA[,Universidad Nacional de Colombia Facultad de Ciencias Departamento de Estadística]]></institution>
<addr-line><![CDATA[Bogotá ]]></addr-line>
<country>Colombia</country>
</aff>
<aff id="A02">
<institution><![CDATA[,Universidad Nacional de Colombia Facultad de Ciencias Departamento de Estadística]]></institution>
<addr-line><![CDATA[Bogotá ]]></addr-line>
<country>Colombia</country>
</aff>
<pub-date pub-type="pub">
<day>15</day>
<month>06</month>
<year>2010</year>
</pub-date>
<pub-date pub-type="epub">
<day>15</day>
<month>06</month>
<year>2010</year>
</pub-date>
<volume>33</volume>
<numero>1</numero>
<fpage>127</fpage>
<lpage>147</lpage>
<copyright-statement/>
<copyright-year/>
<self-uri xlink:href="http://www.scielo.org.co/scielo.php?script=sci_arttext&amp;pid=S0120-17512010000100008&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://www.scielo.org.co/scielo.php?script=sci_abstract&amp;pid=S0120-17512010000100008&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://www.scielo.org.co/scielo.php?script=sci_pdf&amp;pid=S0120-17512010000100008&amp;lng=en&amp;nrm=iso"></self-uri><abstract abstract-type="short" xml:lang="en"><p><![CDATA[A central problem associated with Multidimensional Item Response Theory (MIRT) Models is the impossibility of ordering the examinees. In this paper, we obtain two unidimensional synthetic indices that are optimal linear combinations of the ability vector. These synthetic indices are similar to the reference composite commonly used in MIRT models, but they are easier to calculate and interpret. The synthetic indices are compared with the unidimensional ability obtained when a multidimensional data is fitted with an unidimensional IRT (UIRT) model.]]></p></abstract>
<abstract abstract-type="short" xml:lang="es"><p><![CDATA[Un problema central asociado con los Modelos Multidimensionales de Teoría de Respuesta al Item (TRIM) es la imposibilidad de ordenar a los examinados. En este artículo, se obtienen dos índices sintéticos unidimensionales que son combinaciones lineales óptimas del vector de habilidades. Estos índices sintéticos son semejantes a la composición de referencia comúnmente usada en los modelos TRIM, pero son más fáciles de calcular. Los índices sintéticos se comparan con el parámetro de habilidad obtenido cuando un conjunto de datos multidimensionales es ajustado con un modelo TRI unidimensional.]]></p></abstract>
<kwd-group>
<kwd lng="en"><![CDATA[Binary response]]></kwd>
<kwd lng="en"><![CDATA[Item response theory]]></kwd>
<kwd lng="en"><![CDATA[Index]]></kwd>
<kwd lng="en"><![CDATA[Multidimensional data]]></kwd>
<kwd lng="en"><![CDATA[Synthetic estimator]]></kwd>
<kwd lng="en"><![CDATA[Latent trait]]></kwd>
<kwd lng="es"><![CDATA[respuesta binaria]]></kwd>
<kwd lng="es"><![CDATA[teoría de respuesta al ítem]]></kwd>
<kwd lng="es"><![CDATA[índice]]></kwd>
<kwd lng="es"><![CDATA[datos multidimensionales]]></kwd>
<kwd lng="es"><![CDATA[estimador sintético]]></kwd>
<kwd lng="es"><![CDATA[trazo latente]]></kwd>
</kwd-group>
</article-meta>
</front><body><![CDATA[  <font size="2" face="verdana">      <p> <b> <font size="4">     <center> Synthesizing the Ability in Multidimensional Item Response Theory Models </center> </font> </b> </p>      <p> <b> <font size="3">     <center> Habilidad sint&eacute;tica en modelos multidimensionales de teor&iacute;a de respuesta al &iacute;tem </center> </font> </b> </p>      <p>     <center> &Aacute;LVARO MAURICIO MONTENEGRO D&Iacute;AZ<sup>1</sup>,  EDILBERTO CEPEDA<sup>2</sup> </center> </p>      <p> <sup>1</sup>Universidad Nacional de Colombia, Facultad de Ciencias, Departamento de Estad&iacute;stica, Bogot&aacute;, Colombia. Assistant professor. Email: <a href="mailto:ammontenegrod@unal.edu.co">ammontenegrod@unal.edu.co</a>     <br>  <sup>2</sup>Universidad Nacional de Colombia, Facultad de Ciencias, Departamento de Estad&iacute;stica, Bogot&aacute;, Colombia. Associate professor. Email: <a href="mailto:ecepedac@unal.edu.co">ecepedac@unal.edu.co</a>     <br> </p>  <hr size="1">      ]]></body>
<body><![CDATA[<p> <b>     <center> Abstract </center> </b> </p>      <p> A central problem associated with Multidimensional Item Response Theory (MIRT) Models is the impossibility of ordering the examinees. In this paper, we obtain two unidimensional synthetic indices that are optimal linear combinations of the ability vector. These synthetic indices are similar to the reference composite commonly used in MIRT models, but they are easier to calculate and interpret. The synthetic indices are compared with the unidimensional ability obtained when a multidimensional data is fitted with an unidimensional IRT (UIRT) model. </p>      <p> <b> Key words: </b> Binary response, Item response theory, Index, Multidimensional data, Synthetic estimator, Latent trait. </p>  <hr size="1">      <p> <b>     <center> Resumen </center> </b> </p>      <p> Un problema central asociado con los Modelos Multidimensionales de Teor&iacute;a de Respuesta al Item (TRIM) es la imposibilidad de ordenar a los examinados. En este art&iacute;culo, se obtienen dos &iacute;ndices sint&eacute;ticos unidimensionales que son combinaciones lineales &oacute;ptimas del vector de habilidades. Estos &iacute;ndices sint&eacute;ticos son semejantes a la composici&oacute;n de referencia com&uacute;nmente usada en los modelos TRIM, pero son m&aacute;s f&aacute;ciles de calcular. Los &iacute;ndices sint&eacute;ticos se comparan con el par&aacute;metro de habilidad obtenido cuando un conjunto de datos multidimensionales es ajustado con un modelo TRI unidimensional. </p>      <p> <b> Palabras clave: </b> respuesta binaria, teor&iacute;a de respuesta al &iacute;tem, &iacute;ndice, datos multidimensionales, estimador sint&eacute;tico, trazo latente. </p>  <hr size="1">      <p> Texto completo disponible en <a href="pdf/rce/v33n1/v33n1a08.pdf">PDF</a> </p>  <hr size="1">      <p> <b> <font size="3"> References </font> </b> </p>       ]]></body>
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Zhao, J., McMorris, R. &amp; Pruzek, R. (2002), The Robusnetss of the Unidimensional 3PL IRT when Applied to Two-Dimensional Data in Computarized Adaptive Testing, 'The 2002 annual meeting of American Educational Research Association', New Orleans. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=000068&pid=S0120-1751201000010000800046&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --><center> <b>&#91;Recibido en null de 2009. Aceptado en null de 2010&#93;</b> </center> <hr size="1">      <p> Este art&iacute;culo se puede citar en <i>LaTeX</i> utilizando la siguiente referencia bibliogr&aacute;fica de <i>BibTeX</i>: </p> <code><font size="2">@ARTICLE{RCEv33n1a08,    <br>  &nbsp;&nbsp;&nbsp; AUTHOR &nbsp;= {Montenegro D&iacute;az, &Aacute;lvaro Mauricio and Cepeda, Edilberto},    <br>  &nbsp;&nbsp;&nbsp; TITLE &nbsp; = {{Synthesizing the Ability in Multidimensional Item Response Theory Models}},    ]]></body>
<body><![CDATA[<br>  &nbsp;&nbsp;&nbsp; JOURNAL = {Revista Colombiana de Estad&iacute;stica},    <br> &nbsp;&nbsp;&nbsp; YEAR &nbsp;&nbsp; = {2010},    <br> &nbsp;&nbsp;&nbsp; volume &nbsp;= {33},    <br> &nbsp;&nbsp;&nbsp; number &nbsp;= {1},    <br> &nbsp;&nbsp;&nbsp; pages &nbsp; = {127-147}    <br> }</font></code>  <hr size="1"> </font>      ]]></body><back>
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