PSYC209 Lecture 9: Testing Means - Two independent-sample t Test with confidence interval

• School: University of Delaware
• Department: Psychology
• Course: PSYC209
• Professor: Amey Rachel

Document Summary

A research design in which different participants are observed one time in each group or at each level of one factor. Two ways to do this: observe the same participants twice, select two different groups. A type of sample in which different participants are independently observed one time in each group. Two ways to select two independent samples: select a sample from a population. Used to conduct quasi-experiments: select independent samples. Select one sample from the same population and randomly assign participants in the sample to groups. Used in experiments that include randomization, manipulation and a comparison/control group. A statistical procedure used to compare the mean difference between two independent groups. This test is specifically used to test hypotheses concerning the difference between two population means, where the variance in one or both populations is unknown. We make four assumptions for a two-independent sample t test. Normality: we assume the data in each population being sample are normally distributed.