1. Fundamental Statistics for the Behavioral Sciences, 5th edition David C. Howell Chapter 3 Displaying Data © 2003 Brooks/Cole Publishing Company/ITP

2. 2Chapter 3 Displaying Data Major Points The Sternberg exampleThe Sternberg example Plotting dataPlotting data XHistograms XStem-and-leaf displays XScatterplots Describing distributionsDescribing distributions Review questionsReview questions

3. 3Chapter 3 Displaying Data The Sternberg Example One to five digits displayedOne to five digits displayed Followed by a single digitFollowed by a single digit Was single digit in first set?Was single digit in first set? Predictions of sequential processingPredictions of sequential processing Predictions of parallel processingPredictions of parallel processing

4. The Following is a Simple Demonstration. Click to Begin

5. 5Chapter 3 Displaying Data 4736947369 4 Click Mouse Was the single digit in the comparison set?

6. 6Chapter 3 Displaying Data Plotting Data HistogramsHistograms XValues of dependent variable on X axis discuss grouping or “bins”discuss grouping or “bins” XFrequency on Y axis XHistogram of Sternberg’s data

7. 7Chapter 3 Displaying Data Histogram of Reaction Time

8. 8Chapter 3 Displaying Data Stem-and-Leaf Display Stem-and-leaf of RxTime N = 300 Leaf Unit = 1.0 7 3 6788999 27 4 00001112223333344444 62 4 55555566666666666777777777888899999 103 5 00000111111111111222222222233333333444444 150 5 55555556666666666777777788888888888899999999999 150 6 000000000000111111111112222222222222233333333334444444 96 6 555555556666666677777777777777889999999 57 7 0111122222222333444444 35 7 5566667788899 22 8 000112333 13 8 5678 9 9 044 6 9 558 3 10 44 1 10 1 11 1 12 1 12 5

9. 9Chapter 3 Displaying DataScatterplots Plot two variables against each other.Plot two variables against each other. Points represent coordinates on each axis.Points represent coordinates on each axis. Dependent variable on Y axis.Dependent variable on Y axis. See next slide for exampleSee next slide for example

10. 10Chapter 3 Displaying Data Scatterplot of Solar Radiation and Cancer

11. 11Chapter 3 Displaying Data Describing Distributions SymmetrySymmetry ModalityModality XBimodal XUnimodal SkewnessSkewness XPositively skewed XNegatively skewed

12. 12Chapter 3 Displaying Data Figure 3.9

13. 13Chapter 3 Displaying Data Review Questions What is a frequency distribution?What is a frequency distribution? How does a histogram differ from a bar graph?How does a histogram differ from a bar graph? How does a stem-and-leaf display differ from a histogram?How does a stem-and-leaf display differ from a histogram? What is a scatterplot?What is a scatterplot? Cont.

14. 14Chapter 3 Displaying Data Review Questions --cont. List five terms we use to describe distributions.List five terms we use to describe distributions. What would happen to Figure 3.9 if we collected many more observations from each population?What would happen to Figure 3.9 if we collected many more observations from each population?