Jennifer Darragh Reference Librarian for the Behavioral and Social Sciences Building Statistical Literacy Reading Charts & Graphs

Why are Statistics Important?  Statistics add support to arguments, hypotheses, and theories.  Statistics can provide “snapshot” information about how often something does/doesn’t occur, how it performs/doesn’t perform, and how things can change over time.

Which Statement is Stronger?  I’ve heard a lot of people talking on campus about the election, so I believe there will be more young voters this time around.  According to the Virginia State Board of Elections (2008), the state has experienced the largest surge in voter registrations in Virginia’s history Since January 2008, over 436,000 new voters have registered with almost 40% of the newly registered under the age of 25 by election day. Therefore, it is likely that there will be more young voter participation in Virginia in this election than elections past. Virginia State Board of Elections. (2008, October 15). Virginia state board of elections : RECORD NUMBER OF REGISTERED VOTERS READY TO VOTE IN NOVEMBER [Press release]. Retrieved from OF_REGISTERED_VOTERS_READY_TO_VOTE_IN_NOVEMBER.html OF_REGISTERED_VOTERS_READY_TO_VOTE_IN_NOVEMBER.html

Reading Charts and Graphs  To understand a chart you need to know: 1.What is being measured 2.What is the unit of measurement 3.The relationship between the two  Good charts and graphs tend to be fairly simple and easy to understand. They present information clearly and cleanly. They often refer back to where you can find more details about the data as well. Chart source: Bureau of justice statistics prisoners under sentence of death trends chart. Retrieved 10/16/2008, 2008, from

Reading Charts and Graphs  Statistics can be misleading when: The sample size is too small (a sample of 100 people is not representative of the entire population) Comparing apples to oranges When the wrong type of graph is used (pie charts are big offenders here) When the x or y axis doesn’t have a zero point or percentages don’t add up to 100 or over 100, or there is missing information Chart source: Rock the Vote. (2008). Rock the vote: Young voters: A political powerhouse. Retrieved 10/16/2008 from /electronic-press-kit/2008-young-voters-factsheet.pdf What makes both of these bad bar graphs?

Thinking Critically  When you want to add published statistics to your research paper remember to consider your source (is it authoritative?) the sample size (is it big enough? Are important demographic characteristics – race, age, ethnicity – representated?) whether things add up (is missing information accounted for?)

Further Reading  Best, J. (2001). Telling the truth about damned lies and statistics. Chronicle of Higher Education, 47(34), B7. Accessible through Academic Search Complete Academic Search Complete  Best, J. (2001). Damned lies and statistics : Untangling numbers from the media, politicians, and activists. Berkeley, Calif. ; London: University of California Press. Cabell Library HM535.B47  Huff, D. (1954). How to lie with statistics. pictures ([1.] ed.). New York: Norton. Cabell Library HA29.H82 Should you have any trouble deciphering a statistic or determining whether a graph is valid, please do not hesitate to Ask a Librarian.Ask a Librarian