1. GRAPHS OF MEANS How is a Graph of Means Constructed? What are Error Bars? How Can a Graph Indicate Statistical Significance?

2. How is a Graph of Means Constructed? Construct a bar graph or line graph to show the mean of each condition Independent variable on x-axis Dependent variable on y-axis

3. How is a Graph of Means Constructed? Label units Proportional axes: y = 2/3 to 3/4 x Show error bars

4. 5 x 7: ratio is 71%

5. 6 x 3: ratio is 200%

6. 3 x 8: ratio is 37.5%

7. What are Error Bars? bars showing amount of variability in each condition – confidence intervals – standard deviation units – standard error units

11. How Can a Graph Indicate Statistical Significance? When confidence interval error bars are used, if the mean of one condition falls outside the confidence interval for another condition, then the means of the two conditions are significantly different. The confidence level corresponds to the alpha level, e.g., 95% confidence corresponds to.05 alpha level.