American Journal of Theoretical and Applied Statistics

Volume 11, Issue 4, July 2022

  • Effect of Correlation Between Abilities Under Between-Item Dimensionality

    Xiong Rao

    Issue: Volume 11, Issue 4, July 2022
    Pages: 109-113
    Received: 16 June 2022
    Accepted: 22 July 2022
    Published: 29 July 2022
    DOI: 10.11648/j.ajtas.20221104.11
    Abstract: The Item Response Theory (IRT) evaluates the relationship between people’s ability and test items, and it includes unidimensional and multidimensional models. One key assumption for the unidimensional IRT model is that only one dimension of ability should be tested. However, since people’s abilities are latent, many datasets fitted with the unidime... Show More
  • Adaptive Survey Design for the Dutch Labour Force Survey

    Kees van Berkel

    Issue: Volume 11, Issue 4, July 2022
    Pages: 114-121
    Received: 19 July 2022
    Accepted: 23 August 2022
    Published: 31 August 2022
    DOI: 10.11648/j.ajtas.20221104.12
    Abstract: A challenge for the National Statistical Institutes is to produce reliable statistics with a limited budget for data collection. During the past years, many surveys at Statistics Netherlands were redesigned to reduce costs and to increase or maintain response rates. From 2018 onwards, adaptive survey design has been applied in several social survey... Show More
  • Principal Component Analysis of Standard and Spherical Covariances from the Population and Random Samples to Real and Simulated Data

    Inge Koch, Lyron Winderbaum, Kanta Naito

    Issue: Volume 11, Issue 4, July 2022
    Pages: 122-139
    Received: 12 August 2022
    Accepted: 5 September 2022
    Published: 26 September 2022
    DOI: 10.11648/j.ajtas.20221104.13
    Abstract: Principal component analysis (PCA) is the tool of choice for summarising multivariate and high-dimensional data as features in a lower-dimensional space. PCA works well for Gaussian data, but may not do so well for high-dimensional, skewed or heavy-tailed data or data with outliers as encountered in practice. The availability of complex data has en... Show More