Factor Analysis of Ordinal Variables: Polychoric and Pearson correlations in the exploratory approach
(2021) STAH11 20202Department 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:
http://lup.lub.lu.se/studentpapers/record/9036533
 author
 Emanuelsson, Theodor ^{LU}
 supervisor

 Björn Holmquist ^{LU}
 organization
 course
 STAH11 20202
 year
 2021
 type
 M2  Bachelor Degree
 subject
 keywords
 Exploratory factor analysis, Polychoric correlation, Pearson correlation
 language
 English
 id
 9036533
 date added to LUP
 20210208 08:02:16
 date last changed
 20210208 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}}, }