Vertaile menetelmiä

	Lattia- ja kattoefekti	Faktorianalyysi asteikon kehittämisessä
Tieteenala	Psykometriikka	Psykometriikka
Menetelmäperhe	Process / pipeline	Process / pipeline
Syntyvuosi	2000	1947
Kehittäjä	Classical psychometrics	Louis Thurstone
Tyyppi	Measurement validity assessment	Exploratory factor analysis methodology
Alkuperäislähde	McHorney, C. A. (2000). Ten recommendations for measuring health status. Health-Related Quality of Life Outcomes, 2(1), 1-5.	Thurstone, L. L. (1947). Multiple-Factor Analysis: A Development and Expansion of the Vectors of Mind (2nd ed.). Chicago: University of Chicago Press. ISBN: 9780226797557
Rinnakkaisnimet	Floor effect, Ceiling effect, Psychometric floor effect, Measurement floor	Exploratory factor analysis, EFA for scale development, Factorial structure analysis
Liittyvät	4	5
Tiivistelmä	Floor and ceiling effects are psychometric phenomena in which a disproportionately large proportion of respondents achieve the lowest (floor) or highest (ceiling) possible score on a measurement scale. These effects compromise scale reliability and responsiveness, limiting the instrument's ability to distinguish among respondents and detect meaningful change over time. Systematic assessment of floor and ceiling effects is essential for evaluating the psychometric adequacy of health-related quality-of-life scales, functional status measures, and other patient-reported outcomes.	Exploratory factor analysis (EFA) is a statistical method for discovering the underlying dimensional structure of a set of items or variables. Pioneered by Louis Thurstone in the mid-20th century, EFA is widely used to develop and validate psychometric scales by identifying groups of items that correlate together, thereby revealing latent dimensions of the construct being measured. The method reduces item sets to a smaller number of interpretable factors.