1. Plotting of the data Dot diagram When Analyzing data, always plot the data! A dot diagram: XLXTStren 11.8* * 11.7* ** * * 11.6* ** * * 11.5* * ** 11.4* ** 11.3* * 11.2 * * 11.1 * * * * 11.0 * * 10.9 *

2. Plotting Original Data Always plot original data points. –This is the first thing to do when analyzing data –This is very important!

3. Plotting Cancer Study Results The following plots are from a study by Dr. Terry Rose-Hellekant in the Medical School Duluth Treatments –Tamoxifen –Placebo Some mice develop breast cancer

4. The data are RT-PCR expressions corresponding to particular genes –In RT-PCR the values are roughly a log base 2 scale of the RNA content. PUM1 Is a “housekeeping” gene –Account for RNA quality in the sample –For example time since death for a study of schizophrenia on deceased patients’ brains

11. Two groups can be compared with back to back stem and leaf diagrams E.g. Stopping distances of bikes Treaded tireSmooth tire 341 8 9 355 536 6 4375 38 1391 2 040 Or dot diagrams | | | * | ** | | * |**Treaded 340350 360 370 380 390400 |*** | * | | * | | * |Smooth

12. When there are associations between sets of data values, plot the data accordingly. E.g., Snowfall for duluth and White Bear Lake 1972-2000 A not very good way to plot the data WB Lake Duluth 130* 120* 110** ** 100*** * 90***** 80****** ****** 70** *** 60** ********** 50**** *** 40*** *** 30* *** 20

13. Duluth White Bear

14. A study of trace metals in South Indian River 1 2 3 4 5 6 T=top water zinc concentration (mg/L) B=bottom water zinc (mg/L) 123456 Top0.4150.2380.3900.4100.6050.609 Bottom0.4300.2660.5670.5310.7070.716

15. One of the first things to do when analyzing data is to PLOT the data This is not a useful way to plot the data. There is not a clear distinction between bottom water and top water zinc even though Bottom>Top at all 6 locations.

16. A better way TopBottom Connect points in the same pair.

17. A better way Bottom=Top

18. This following plot would imply a natural ordering of sites from 1 to 6. This would not be the best way to plot the data unless the sites 1-6 correspond to a natural ordering such as distance downstream of a factory.