PSYC37H3 Chapter Notes - Chapter 4: Factor Analysis, Takers, Classical Test Theory
Document Summary
Observed score (x) = true score (t) + error (e) Chapter four: assumption: each person has a true score that would be obtained if there were no measurement errors. Some tests get closer to measuring true scores than others. Can we ever really know the true score : assumption: errors of measurement are random. As opposed to systematic: rubber yardstick analogy. Randomly stretches or shrinks each time you take a measurement: sampling theory suggests that the distribution of random errors is bell-shaped, or normally distributed (recall: normal curve). Degree of spread around the middle (mean) reflects the amount of sampling error. Parallels the concept of standard deviation around a mean. Standard error of measurement: the standard deviation of errors is the basic measure of error in classical test theory. Domain sampling model: considers the problems created by using a limited number of items to represent a larger and more complicated construct: e. g. , neuroticism.
