PSYC 2360 Chapter Notes - Chapter 5: Pearson Product-Moment Correlation Coefficient, Inter-Rater Reliability, Internal Consistency

• School: University of Guelph
• Department: Psychology
• Course: PSYC 2360
• Professor: Carol Anne Hendry

Document Summary

The most common measurement strategy is to ask people to tell you about themselves. Thus, it is very important that you use a reliable measure. In many areas, reliability can be increased by making multiple measures. Test-retest reliability: assessed by measuring the same individuals at two points in time ex. measuring a group of people on one day and again a week later. If many people have very similar scores, we conclude that the measure reflects true scores rather than measurement error. Researchers have devised methods to assess reliability without two separate assessments. Recall that reliability increases with increasing numbers of items. Internal consistency reliability is the assessment of reliability using responses at only one point in time. Here the researcher calculates the correlation of each item with every other item. The value of alpha is based on the average of all the interitem correlation coeffs and the number of items in the measure.