1. Statistical Analysis – Part 2
Yale Braunstein
School of Information Management & Systems

2. Sources of Error The respondent The investigator Sampling error
Change in the system itself
Coding & analysis
Other

3. Measures of Central Tendency
Distinguish between numerical & categorical data
Understand the differences between the different measures of “the average”
Mean
Median (middle value)
Mode (most common value)
Example: David Lazarus on PG&E bonus payments, SF Gate, March 12, 2003.
Consider the dispersion around the center

4. Demos of Excel & SPSS
Sample data sets available from the course download page
Student height & weight
Oakland voter profile
U.S. colleges (with detailed comparison of 4 private colleges)
There are also links to:
Comparison of Excel & SPSS
MS for “Pivot Table Reports 101”
SPSS “flow of logic” handout
SPSS FAQ

5. Specific Topics Covered
Measures of central tendency (various forms of “averages”)
Frequencies
Histograms
Cross-tabulations
Value labels
Recoding & transforming data
Missing data or observations
Documenting data files, transformations, procedures, etc.
[The last 5 are some of the strengths of SPSS]