1. Unit 4: Statistical Significance Lesson 1: Constructing Confidence Intervals EDER 6010: Statistics for Educational Research Dr. J. Kyle Roberts University of North Texas Next Slide

2. Mean Differences IQ Scores Next Slide 100 115 85

3. Standard Error of the Mean Sample of IQ Scores Mean = 100 SD = 15 N = 25 Next Slide SEM X

4. Critical Values 95% Confidence Intervals Next Slide -1.96 SD +1.96 SD

5. Computing the CI 95% CI 95% = 100 ± (1.96)(3) CI 95% = 100 ± 5.88 -or- CI 95% : 105.88 – 94.12 Next Slide Sample of IQ Scores Mean = 100 SD = 15 N = 25

6. What Does a CI Tell Me? CI 95% = 100 ± 5.88 1. We are 95% confident that the interval around our obtained mean contains the population mean. 2. If we continued to sample from the population an infinite number of times, 95% of those sample means and confidence intervals would capture the population mean. Next Slide

7. Confidence Intervals from a Population Next Slide

8. Unit 4: Statistical Significance Lesson 1: Constructing Confidence Intervals EDER 6010: Statistics for Educational Research Dr. J. Kyle Roberts University of North Texas