Lecture 1 Flashcards
Intro to Psychometric Theory
How do we measure psychological phenomena?
Directly and Indirectly
What is Psychometric Theory?
The Measurement or Quantification of psychological constructs through various instruments or psychological tests
What is Measurement?
Scaling - assignment of numeral to objects or events according to rules
Classification - define whether the objects falls in the same or different categories with respect to a given attribute
How do psychological theories become testable?
-Operationally Define
-Develop an Instrument to measure area
-Measurement (quantitative value is assigned to the behavior)
Test can be re-used
What is the Hallmark of good Measurement?
Some form of Standardization
Measurement of Attributes
Do not measure objects but the attributes or properties of those objects
What are the advantages of Standardized Measures?
Objectivity - independently verifiable
Quantification - numerical details, greater detail than personal judgment
Communication - lexicon is uniform
Economy - save time and money
What is the difference between psychometric theory and traditional statistics?
Descriptive vs. Inferential
Sampling content vs objects
What are the 4 types of scales?
Nominal, Ordinal, Interval, and Ratio
Describe Nominal scales
Track categories of individuals, male vs female, only coded for frequency
Describe Ordinal Scales
Ordered from “most” to “least” with respect to an attribute
Describe Interval Scales
rank ordering objects, no absolute 0, ordinal scale with numbers added
Describe Ratio Scales
have a true 0, hard sciences use these, equal distance between units
What is the Representational Model?
a scale must have proven interval properties before it can be used
it must be ostensive
