Cancer: A Global View

1. Cancer:A Global View Gretchen A. Koch Goucher College PEER UTK 2011

2. Special Thanks To: • Dr. Claudia Neuhauser • University of Minnesota – Rochester • Author and creator of modules

3. Learning Objectives After completion of this module, the student will be able to: • Explore “social, economic and environmental development at local, national and global levels” with Gapminder. • Perform and interpret logarithmic transformations for graphical display. • Download global health data from Gapminder and WHOSIS.

4. Prerequisites • Calculating percent changes • Straight lines • Natural logarithm, exponential function • Graphing in Excel • Fitting a straight line to data points in Excel and displaying the equation

5. Knowledge Gained • Logarithmic transformations • Continuous time population models • Fitting a straight line to data

6. Teaching Style • See It • Do It • Teach It

7. Learning Objective 1: Gapminder • A visualization tool to animate statistics and data to see trends over time • Downloadable data sets • Interactive graphical resources • Unique visualization techniques • Ex: Size and color of each country’s circle are significant. • Video #1: Breast Cancer Statistics • Video #2: Lung Cancer Statistics

8. Think, Pair, Share • What features about Gapminder were most intriguing? • What, if anything, confused you about Gapminder? • What relationships would you like to explore with respect to breast cancer and lung cancer in Gapminder? Time to Share

9. Think, Pair, Share • Complete In-Class Activity #2 in the Cancer Global View document • Pay special attention to what happens when you change the scale of the graph Time to Share

10. Summarizing

11. Learning Objective 2: Logarithmic Transformations • Gapminder World: • Lung cancer, new cases per 100,000 men versus Income per Capita • Linear y-axis with linear x-axis • Logarithmic y-axis with linear x-axis • Linear y-axis with logarithmic x-axis • Logarithmic y-axis with logarithmic x-axis

12. Learning Objective 2: Logarithmic Transformations Same data – different visualizations: Logarithmic versus Logarithmic Linear versus Linear

13. Learning Objective 2: Logarithmic Transformations Same data – different visualizations: Logarithmic versus Linear Linear versus Linear

14. Learning Objective 2: Logarithmic Transformations On the axes above, find the following numbers: x=0.05, 0.2, 8, 15, 750. Why do you think we choose logarithms to base 10, instead of some other base? Can you plot negative numbers on a logarithmic scale? As x approaches 0, where would you find x on a logarithmic scale?

15. So what is really happening? • Case 1: Both axes are logarithmic.

16. Log/Log Graphs • Log/Log transformation = straight line

17. Log/Log Graphs • Applying our rules for logarithms:

18. Log/Log Graphs • Applying our rules for logarithms:

19. Log/Log Graphs • Applying our rules for logarithms:

20. Log/Log Graphs • Applying our rules for logarithms:

21. Log/Log Graphs • Applying our rules for logarithms:

22. Log/Log Graphs • Applying our rules for logarithms:

23. Log/Log Graphs • Applying our rules for logarithms:

24. Log/Log Graphs • If we substitute in a constant, we find

25. Log/Log Graphs • If both axes are transformed logarithmically, producing a straight line, then the relationship between x and y is that of a power function:

26. Case 2: Semi-log Graphs • In this case, the x-axis remains linear, while the y-axis is transformed logarithmically.

27. Case 2: Semi-log Graphs • Again, let us assume that a straight line results from this transformation.

28. Case 2: Semi-log Graphs • If we transform the y-axis logarithmically, leave the x-axis linear, and a straight line results, what is the relationship between the data points? Time’s Up!

29. Case 2: Semi-log Graphs

30. Case 2: Semi-log Graphs • If we transform the y-axis logarithmically, leave the x-axis linear, and a straight line results, then the relationship between x and y is an exponential function.

31. Exploring Data in Excel • Download the Excel data file from the Schedule page • Click on the Parakeet tab. Highlight both columns of data. • Choose Charts  Scatter  Marked Scatter. • Click on the legend and delete it. • Click on the title and change it. • Choose Chart Layout  Axis Titles  Horizontal  Title Below the Axis. Pick an appropriate name. Repeat the process for the Vertical Axis. • To make the horizontal axis start at 76 (not 0), right click on the horizontal axis. Select Format Axis. Uncheck the Minimum box, and put 76 in as the minimum. • Options for logarithmic transformations can be found under Chart Layout  Axes Horizontal • If your axes do not look correct (i.e. the horizontal axis is not at the bottom of the graph), right click on the vertical axis. Select Format Axis. Ensure that the horizontal axis crosses at the minimum value of the vertical axis.

32. Fitting Data in Excel • Graph your data on the scales desired. • Select the graph. Choose Chart Layout  Trendline Trendline Options  Options. Choose to display the equation on the chart, as well as displaying the R-squared value on the chart. • Select the graph. Choose Chart Layout  Trendline Trendline Options  Type. Try various options for the fit type, keeping in mind that the transformed graph should guide your decision. Note that an R-squared value closer to one indicates a stronger correlation between the two variables.

33. Group Activity • Fit an appropriate function to the Parakeet data. • Fit an appropriate function to the Plantain data. • Compare with your neighboring group.

34. Learning Objective 3: Downloading Data • Follow the directions in the Cancer Global View pdf (starting on the bottom of page 6) to download data from Gapminder and WHO (links can be found on the schedule page). • Complete the group project involving the mash-up data provided. Create a blog entry reflecting on your results.