Market Research: Foundations to Practice · Analyzing and Interpreting Data
Descriptive Statistics: Beyond the Average
Reporting only a mean can hide meaningful differences within a dataset, sometimes badly. This chapter covers why a fuller picture requires distribution shape, not just a single central number.
Reporting only a mean (average) score can obscure meaningful differences in how a population's responses are actually distributed; two groups can share an identical mean satisfaction score while one group is genuinely uniformly satisfied and the other is sharply polarized between very satisfied and very dissatisfied respondents, a critical difference the mean alone completely hides from view.
Key Takeaways
- Two groups can share an identical mean while one is uniformly satisfied and the other sharply polarized; the mean alone hides this critical difference.
- Median and mode provide complementary information: median resists outlier distortion, mode reveals the single most common response.
- Examining full distribution shape, not just summary statistics, reveals clustering versus polarization, which calls for different follow-up analysis.
- Standard deviation quantifies spread around the mean; reporting it alongside the mean shows how representative that average actually is of the full dataset.