Psychology 2080A/B Chapter 4: Chapter 4 - Reliability

• School: Western University
• Department: Psychology
• Course: Psychology 2080A/B
• Professor: Patrick Brown

Document Summary

In psych testing, error does not imply mistake has been made rather than having negative connotation, error implies that there will always be some inaccuracy in our measurements. Tests that are relatively free of measurement error are said to be reliable. Psychology owes advanced development of reliability assessment to early work of british psychologist charles spearman. Abraham de moivre introduced notion of sampling error, karl pearson developed product moment correlation, and reliability theory put these two concepts together in context of measurement. Spearman worked out most of the basics of contemporary reliability theory and published his work in article the proof and measurement of association between two things . Because measuring instruments are imperfect, the score observed for each person always differs from the person"s true ability or characteristic. In symbolic representation, the observed score (x) has two components; a true score (t) and an error component (e): x = t + e (x is observed score)