IST:622 Term 4
Week 3 Objectives
- Identify different samples and determining which statistical procedure to use for data analysis
- Interpret meaning of scores, measurement and scientific inquiry
- Develop an appropriate evaluation plan for a given project
- Videos-
- Independent sample t-test
- MAC t-test 2 sample for means unequal
- MAC t-test sample paired difference
- Reading Assignments
- Russ-Eft & Preskill: Chap 5
- Pedhazur & Schmelkin Article
- Paired Sample t-test example
- Independent sample t-test example
- Lecture- Inferential Statistics (Week 3) (See accordion below)
Assignment
Follow instructions from Data File and Lab Instruction
Practice Questions-
- SAT scores of 100 girls compared to SAT scores of 100 boys in a private school in California. Are these dependent or independent samples? What is the degree of freedom? (Answer: These are independent samples because there is no indication of matching, pairing, or repeated measure. Therefore, the df=100+100-2=198)
- Twenty-five first graders' mid-term and end-of-term math exam scores are compared. Dependent or independent sample? What is the degree of freedom? (Answer: These are dependent samples because each student's mid-term score is compared to his/her end-of-term score. This is an example of repeated measure. Therefore, the df=25-1=24)
Lecture Notes
Inferential Statistics (Week 3)
Four Ways to Obtain Samples
Independent vs. dependent sample-
How Inference Works t-test for dependent samples- Is a process for determining if there is a statistically significant difference between the means of two dependent samples. (slide 19) For additional information review examples at: http://www.uwsp.edu/PSYCH/stat/11/hyptest2s.htm Summary- Inferential statistics tell us how much confidence we can have when we generalize from a sample to a population. In choosing the proper inferential statistic, an analyst must consider the size and number of samples drawn and the nature of the measures taken. |