Sökning: "Dag Sörbom"

Hittade 3 avhandlingar innehållade orden Dag Sörbom.

  1. 1. Observed score equating with covariates

    Författare :Kenny Bränberg; Marie Wiberg; Xavier de Luna; Dag Sörbom; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Equating; observed score equating; true scores; item response theory; linear equating function; equipercentile equating; kernel equating; covariates; linear regression; mean squared error; Statistics; Statistik; Statistics; statistik;

    Sammanfattning : In test score equating the focus is on the problem of finding the relationship between the scales of different test forms. This can be done only if data are collected in such a way that the effect of differences in ability between groups taking different test forms can be separated from the effect of differences in test form difficulty. LÄS MER

  3. 2. On the Measurement of Model Fit for Sparse Categorical Data

    Författare :Katrin Kraus; Dag Sörbom; Ghazi Shukur; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; goodness-of-fit; sparseness; model fit; categorical data; fit statistic; sparse contingency table; Statistics; Statistik;

    Sammanfattning : This thesis consists of four papers that deal with several aspects of the measurement of model fit for categorical data. In all papers, special attention is paid to situations with sparse data. LÄS MER

  4. 3. Intelligence and models for cognitive development

    Författare :Linda Wänström; Daniel Thorburn; Gösta Hägglund; Dag Sörbom; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; intelligence; cognitive development; sample size; multilevel models; latent growth curve models; Statistics; Statistik; statistik; Statistics;

    Sammanfattning : This dissertation focuses on cognitive development. In papers I and II, I study a special model, the second order latent growth curve model, that can be used to study cognitive development. Algebraic expressions for the variance of the estimation of slope differences are given. LÄS MER