TY - CHAP
T1 - Ordinal outcome variables
AU - Leppink, Jimmie
PY - 2019
Y1 - 2019
N2 - A commonly undervalued and mistreated type of outcome variable is the ordinal one. Two common types of mistreatment are treating ordinal variables as interval/ratio level outcome variables (frequently in linear models) and, in other cases, as multicategory nominal outcome variables. Multicategory nominal outcome variables are covered in Chap. 6 and quantitative outcome variables in Chap. 8 of this book. What these two types of mistreatment have in common is that they more often than not may result in outcomes that do not make sense. Where we treat ordinal variables as if they were (at least) interval, we may see linear relations where they do not make sense. Where we treat ordinal variables as if they were nominal, we treat all categories as exchangeable and lose the information with regard to the order of categories and, to a large extent, the meaning of outcomes with it. Although many of the concepts discussed in the context of dichotomous (Chap. 5) and multicategory nominal outcome variables also have their use, we need to take an additional step to respect the ordinality information when dealing with ordinal outcome variables. Differences between approaches to ordinal data encountered in the literature are discussed first in terms of animal comparisons (mice, hedgehogs, cats, bears, and elephants) and then in the form two experiments each of which indicates a different type of treatment effect.
AB - A commonly undervalued and mistreated type of outcome variable is the ordinal one. Two common types of mistreatment are treating ordinal variables as interval/ratio level outcome variables (frequently in linear models) and, in other cases, as multicategory nominal outcome variables. Multicategory nominal outcome variables are covered in Chap. 6 and quantitative outcome variables in Chap. 8 of this book. What these two types of mistreatment have in common is that they more often than not may result in outcomes that do not make sense. Where we treat ordinal variables as if they were (at least) interval, we may see linear relations where they do not make sense. Where we treat ordinal variables as if they were nominal, we treat all categories as exchangeable and lose the information with regard to the order of categories and, to a large extent, the meaning of outcomes with it. Although many of the concepts discussed in the context of dichotomous (Chap. 5) and multicategory nominal outcome variables also have their use, we need to take an additional step to respect the ordinality information when dealing with ordinal outcome variables. Differences between approaches to ordinal data encountered in the literature are discussed first in terms of animal comparisons (mice, hedgehogs, cats, bears, and elephants) and then in the form two experiments each of which indicates a different type of treatment effect.
U2 - 10.1007/978-3-030-21241-4_7
DO - 10.1007/978-3-030-21241-4_7
M3 - Chapter
SN - 978-3-030-21240-7
T3 - Springer Texts in Education
SP - 103
EP - 116
BT - Statistical methods for experimental research in education and psychology
PB - Springer
CY - Switzerland
ER -