Introduction
What is measurement? Measurement is the assignment of numbers to attributes of objects according to rules in such a way that the numbers correspond to the attribute.
Example:
Object(s): Apples
Attributes: Age, color, sweetness, cunning
Measures:
age: months since blossom, or days or hours since picked
color: comparison to color chip or judgment of redness (at the moment what counts in not whether it is red or green, but how red it is)
sweetness: chemical sugar analysis or judgment
cunning: huh? since when are apples crafty?
Measurement is fundamental to psychology as a scientific enterprise.
1. Agreement -- how many teeth does a cow have?
2. Replication -- chemical and alchemical labs
3. Quantification of error -- how far wrong?
4. Fair treatment of objects by different folks. Tests originally developed to remove bias from judgment
What is a test? "a systematic procedure for observing behavior and describing it with the aid of numerical scales or fixed categories."
Vocabulary:
Group and Individual tests: individual tests are given to one person at a time; group tests can be administered to many people at once.
Standardized: if a test is standardized, the test administration and context is uniform across those tested.
Objective: a test is said to be objective if observers or scorers arrive at the same numbers when they see the same behavior.
Brief History of Testing
Civil service in China.
Ability tests. Began with Binet & Simon about 1900. The test was brought to the U.S. by Terman in California.
Personality testing. Began in early 1900s. Questions like "do you wet the bed?" and "do you drink a quart of Scotch a day?"
Cronbach: Ability tests for maximum performance; personality for typical behavior.
Some attacks on Personality testing:
1. Unrealistic assumptions -- questions taken at face value
2. Invasive
3. Don't work
Some attacks on Ability testing:
1. Unfair -- cultural bias; choking
2. Harmful interpretations -- you are retarded or almost a genius
Major uses of tests:
1. Selection/classification
a. for privilege
schools
jobs
b. for remediation
special classes
clinical diagnosis & treatment
2. Self knowledge -- vocational choice
3. Evaluation
schools
workplace
military
4. Scientific enterprises
e.g., job satisfaction and longevity
e.g., teamwork and aircraft safety