Psychometrics Flashcards
What is Psychometrics?
Is the science concerned with evaluating the attributes of psychological tests
- Scores Generated
- Validity of Data
- Reliability of Data
Primary Foundation of Psychometrics
psychological testing and measurement
Secondary Foundation of Psychometrics
Development of statistical concepts and procedures
What is a Psychological test?
Systematic procedure for comparing the behavior of two or more people
- Include behavior samples
- Behavior samples are collected in systematic way
- Purpose is to detect differences between people
What is Absolute 0
Zero represents a state in which an attribute has no existence (e.g.,
confidence, range of motion)
What is Arbitrary Zero
An arbitrary or relative quantity of an attribute, e.g., temperature – 0 on Celsius scale is the melting point of ice (and not absence of temperature)
Types of Tests
- Criterion Referenced Tests
- Norm Referenced Test
What are Criterion Referenced Tests?
- Decision must be made about a person’s skill level
- Cut-off score is established as a criterion – used to sort people into 2 groups:
Ex. Frailty, or fall risk
What are Norm referenced Tests?
- Used to understand how a person compares with other people
- Compares a persons score with scores from a normative sample
Ex. Growth charts, Developmental age
How can Psychological tests test unobservable characteristics?
- Use of them as instruments
- Link observable behavior with unobservable psychological attributes
What are Latent Variables
Unobservable psychological attributes
What are Challenges to measurement in Psychology?
- Complexity of concepts
- Participants Reactivity
- Observer Expectancy/Bias
- Composite Scores
- Score Sensitivity
- Lack of Awareness of Psychometrics
- Accuracy of measurement
What is participant Reactivity
It is: the change in outcome due to consciousness
Different forms of Participant Reactivity?
- Demand Characteristics: Change in behavior to accommodate purpose of test
- Social Desirability: Change in behavior to impress clinician
- Malingering: Change behavior to convey a poor impression
- Observer Bias: Vested interest in certain test score outcomes to influence test procedures
What is Score Sensitivity?
- A measure’s ability to discriminate between meaningful amounts of the dimension being measured
- Some tests may not be sensitive enough to discriminate between small but important differences
What is scaling?
assigning numerical values to psychological attributes
Levels of Scaling? (in order from weakest to strongest data)
Nominal, Ordinal, Interval, and Ratio (in order from weakest to strongest data)
What is a Nominal Scale
typically a system of classification; no meaningful mathematical qualities
- Is distinctive but does NOT order magnitude, have equal intervals, or has an absolute zero
Ex. Religion, hair color, etc.
What is an Ordinal Scale
Ranks the amount of property to be valued; monotonic property
Consists of rank-ordered categories for > or < relationship (Likert Scale)
- Is Distinctive and orders magnitude but DOES NOT have equal intervals or has an absolute zero
Ex. How happy are you? Answers: depressed, somewhat depressed, neutral, somewhat happy, elated
Interval Scale
Presence of equal interval points
- Is Distinctive, orders magnitude, and has equal intervals but DOES NOT have an absolute zero
Ex. Temp
Ratio
Has an absolute zero point from which measures become ratios; true quantitative measure.
- Is Distinctive, orders magnitude, has equal intervals and has an absolute zero
Ex. # of items correctly recalled
Person Centered Measurement
Measurement model that focuses on the person, not the instrument, to produce a picture of the client through their response patterns
What is a Demand Characteristic of Patient Reactivity?
Change in behavior to accommodate purpose of test
What is social desirablility in participant reactivity?
Change in Behavior to impress clinician
What is malingering in participant reactivity?
Change in behavior to convey poor impression
What is observer bias in participant reactivity?
Vested interest in certain test score outcomes to influence test procedures
