PSYC 2250 Lecture Notes - Lecture 12: Statistical Inference, Descriptive Statistics, Random Assignment

• School: University of Manitoba
• Department: Psychology
• Course: PSYC 2250
• Professor: Hladkyj

Document Summary

Chapter 12: understanding research results: describing variables and the. Two reasons for using statistics: to describe data from the sample = descriptive statistics, to make inferences from the sample to the population = inferential statistics. Four types: nominal: categories, simple coding of categories, numbers have no meaning, ordinal: ordering, ranking, numbers represent order, measures magnitude and direction, but intervals are not equal and no absolute zero. Interval: equal distances: numbers have magnitude, order, and intervals are equal, ratio: equidistant + true zero, order, equal intervals, plus (absolute) zero, magnitude, direction, comparable and zero is a true possibility. *sometimes difficult to decide if something is interval or ratio. Often useful to assume that rating scales are interval: statistically, more can be done with them can use parametric tests. Be skeptical: like random assignment to groups, like pilot studies. Conceptually different (ratio scale has true zero), but statistical analysis is the same.