1. Measurement & Analysis: The Missing Link Katherine McKnight, Ph.D. Director of Research & Evaluation Pearson School Achievement Services

2. The Main Thing How we measure our variables directly influences how we ought to analyze them

3. What is measurement? Assigning numbers to our observations The numbers reflect different properties of those observations (e.g., magnitude, frequency, amount) Goal: to map our numbers onto the phenomenon of interest as closely as possible

4. Measures that Categorize 1 = Male 2 = Female 1 = up to 30 yrs old 2 = 30 – 39 yrs old 3 = 40 – 49 yrs old 4 = 50 – 59 yrs old 5 = 60 – 69 yrs old 6 = 70+ yrs old 1 = African American 2 = Hispanic 3 = Asian 4 = Caucasian 5 = Other

5. Categorical Data DESCRIPTIVE STATISTICS MEDIAN AGE CATEGOY = 2 (Ages 30 – 39) MEAN = 2. 4 (between 30-39 and 40-49?) < 30 yrs = 1 30-29 = 2 40-49 = 3 50-59 = 4 60-69 = 5 70+ yrs = 6

6. Binary Measures 0 0 0 1 1 MEAN = 2/5 = 40%

7. Measures that rank or order things

8. Measures that Rank or Order Things -2 Disagree Strongly 2 Agree Strongly Disagree Somewhat 1 Agree Somewhat 0 Neutral Central Tendency Median2.0 Mean1.32

9. Measures of Magnitude

10. Comparing Groups % of body fat lost MalesFemales 0.050.11 0.120.34 0.0010.27 0.250.12 0.50.003 0.230.08 0.170.16 0.020.24 Mean 0.17

11. Measurement & Data Presentation

12. Some Resources Books: 1.What is a P-Value Anyway? 34 Stories to Help You Actually Understand Statistics – by Andrew Vickers (2010). www.pearsonhighered.comwww.pearsonhighered.com 2. The Cartoon Guide to Statistics – by Larry Gonick & Woollcott Smith (1993). Published by Harper Perennial, available at www.amazon.comwww.amazon.com 3. Discovering Statistics Using SPSS (3rd Edition), by Andy Field. Published by Sage, available at www.amazon.comwww.amazon.com 4. Visualizing Data, by William Cleveland (1993). Published by Hobart Press. Available at www.amazon.com www.amazon.com 5. The Elements of Graphing Data, by William Cleveland (1994). Published by Hobart Press. Available at www.amazon.comwww.amazon.com

13. Some Resources Websites: 1.Final slide’s table is from http://www.slideshare.net/nebraskaccess/ncompass-live- presenting-data-in-meaningful-and-interesting-wayshttp://www.slideshare.net/nebraskaccess/ncompass-live- presenting-data-in-meaningful-and-interesting-ways 2.Check out YouTube for a variety of statistics videos, e.g., www.youtube.com/watch?v=YHXadaW_lso (more info on this series at www.perdisco.com) www.youtube.com/watch?v=YHXadaW_lso www.perdisco.com 3.Perdisco’s Introductory Stats course (YouTube video above is from this series): http://www.perdisco.com/statistics/ist2.aspx http://www.perdisco.com/statistics/ist2.aspx