Presentation on theme: "Visual Displays of Data Chapter 3. Uses of Graphs >Positive and negative uses Can accurately and succinctly present information Can reveal/conceal complicated."— Presentation transcript:
Uses of Graphs >Positive and negative uses Can accurately and succinctly present information Can reveal/conceal complicated data >Graphing in the information age: a critical skill
“The Most Misleading Graph Ever Published” The Cost and Quality of Higher Education How to Mislead with Graphs
Techniques for Misleading >The false face validity lie Method seems to represent what it says, but does not actually. >e.g., using yelling as a measure of aggression >The biased scale lie Scaling to skew the results >e.g., using 3 positive words out of 5 options >The sneaky sample lie When participants are preselected or self selected to provide data.
More Techniques >The interpolation lie Assumes that a value between 2 data points follows the same pattern >The extrapolation lie Assumes knowledge outside of the study >The inaccurate values lie Uses scaling to distort portions of the data >The outright lie: Making up data!
Check Your Learning >What is the best type of graph to depict the following: Depression levels and stress levels for 150 university students. Is depression related to stress? Mean years of education for six regions of the United States. Are education levels higher in some regions than in others?
How to Build a Graph > APA style: Graphing guidelines for social scientists 1.Refer to tables and figures in the text by number, and briefly describe them. 2.Place the final, camera-read versions of the actual tables and figures at the end of the manuscript. 3.Provide a complete and clear caption for every figure on a separate page.
APA style (cont.) 4.Write the number of the figure in pencil as close as possible to the top right of the final copy of the figure. 5.Write the manuscript’s short title and the word TOP on the back of the final copy to indicate the top of the figure.
1.One scale variable (with frequencies): histogram or frequency polygon 2.One scale independent and one scale dependent variable: scatterplot or line graph 3.One nominal or ordinal independent and one scale dependent variable: bar graph 4.Two+ nominal or ordinal independent and one interval dependent variable: bar graph Choosing the Graph Based on Variables
Creating the Perfect Graph >General guidelines Use the same terms as in the body of the text Tell its entire story without forcing the reader to go back to the text Use clear title, labels
Check Your Learning What is the likely lie? 1.Do smarter people attend statistics class more often? Statistics grades were on the x- axis and percentages of classes attended were on the y-axis. 2.Your professor asserts that you should not become a political scientist, showing a time plot that depicts a decrease in job openings over the last 10 years. The job prospects can only decrease you are warned.