PSYC 406 Lecture Notes - Lecture 4: Item Response Theory, Classical Test Theory, Inter-Rater Reliability

• School: McGill University
• Department: Psychology
• Course: PSYC 406
• Professor: David Vachon

Document Summary

Quiz 1 review: law school: 100 students get in, 1000 students are rejected. 100 students who get in 80 people will get in correctly, 20 people get in, but they were told they were rejected (type ii error, false negative) Classical test theory: requires that exactly the same test items be administered to each person. Item response theory: the computer is used to focus on the range of item difficulty that helps assess an individual"s true ability. For example, if the person gets several easy items correct, the computer might quickly move on to more difficult items. If a person gets several difficult items wrong, the computer moves back to the easier items where the person gets a combination of correct and incorrect. This results in a more reliable estimate of ability in a shorter test with few items. Issue: the bank of items must be evaluated for level of difficulty.