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Factor Analysis of Ordinal Variables: Polychoric and Pearson correlations in the exploratory approach

Emanuelsson, Theodor LU (2021) STAH11 20202
Department of Statistics
Abstract
This thesis considers the problem of applying exploratory factor analysis to data obtained though the Likert scale. It is often the case that this sort of data is treated as an interval level of measurement and used in analyses that require continuous variables, although given the categorization and nature of the scale, it should rather be treated as of ordinal level. Exploratory factor analysis is a prevailing technique for studying the construct validity of data, a method that relies on the correlation matrix of the data to obtain factor solutions. Previous research recommend the use of polychoric correlations as opposed to the common Pearson correlation method when attempting to apply factor analysis to ordinal data. Preceding research... (More)
This thesis considers the problem of applying exploratory factor analysis to data obtained though the Likert scale. It is often the case that this sort of data is treated as an interval level of measurement and used in analyses that require continuous variables, although given the categorization and nature of the scale, it should rather be treated as of ordinal level. Exploratory factor analysis is a prevailing technique for studying the construct validity of data, a method that relies on the correlation matrix of the data to obtain factor solutions. Previous research recommend the use of polychoric correlations as opposed to the common Pearson correlation method when attempting to apply factor analysis to ordinal data. Preceding research is complemented with further consideration of asymmetry
in the data. The results, obtained through simulation studies, show that the polychoric correlations provide a more accurate reproduction of the theoretical model used to generate the data in three cases of item skewness. (Less)
Please use this url to cite or link to this publication:
author
Emanuelsson, Theodor LU
supervisor
organization
course
STAH11 20202
year
type
M2 - Bachelor Degree
subject
keywords
Exploratory factor analysis, Polychoric correlation, Pearson correlation
language
English
id
9036533
date added to LUP
2021-02-08 08:02:16
date last changed
2021-02-08 08:02:16
@misc{9036533,
  abstract     = {{This thesis considers the problem of applying exploratory factor analysis to data obtained though the Likert scale. It is often the case that this sort of data is treated as an interval level of measurement and used in analyses that require continuous variables, although given the categorization and nature of the scale, it should rather be treated as of ordinal level. Exploratory factor analysis is a prevailing technique for studying the construct validity of data, a method that relies on the correlation matrix of the data to obtain factor solutions. Previous research recommend the use of polychoric correlations as opposed to the common Pearson correlation method when attempting to apply factor analysis to ordinal data. Preceding research is complemented with further consideration of asymmetry
in the data. The results, obtained through simulation studies, show that the polychoric correlations provide a more accurate reproduction of the theoretical model used to generate the data in three cases of item skewness.}},
  author       = {{Emanuelsson, Theodor}},
  language     = {{eng}},
  note         = {{Student Paper}},
  title        = {{Factor Analysis of Ordinal Variables: Polychoric and Pearson correlations in the exploratory approach}},
  year         = {{2021}},
}