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  1. Introduction
  2. Graphing Distributions
  3. Summarizing Distributions
  4. Describing Bivariate Data
  5. Probability
  6. Research Design
  7. Normal Distribution
  8. Advanced Graphs
  9. Sampling Distributions

  10. Estimation
    1. Contents
      Standard
    2. Introduction
      Standard
         Video
    3. Degrees of Freedom
      Standard
         Video
    4. Characteristics of Estimators
      Standard
         Video
    5. Bias and Variability Simulation
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    6. Confidence Intervals
      Standard
         Video
    7. Confidence Intervals Intro
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         Video
    8. Confidence Interval for Mean
      Standard
         Video
    9. t distribution
      Standard
         Video
    10. Confidence Interval Simulation
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    11. Difference between Means
      Standard
         Video
    12. Correlation
      Standard
         Video
    13. Proportion
      Standard
         Video
    14. Statistical Literacy
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    15. Exercises
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  11. Logic of Hypothesis Testing
  12. Tests of Means
  13. Power
  14. Regression
  15. Analysis of Variance
  16. Transformations
  17. Chi Square
  18. Distribution Free Tests
  19. Effect Size
  20. Case Studies
  21. Calculators
  22. Glossary
 

Statistical Literacy

Author(s)

David Lane

No "Large Conclusions" from "Tiny" Samples?

Prerequisites

Proportions

In July of 2011, Gene Munster of Piper Jaffray reported the results of a survey in a note to clients. This research was reported throughout the media. Perhaps the fullest description was presented on the CNNMoney website (A service of CNN, Fortune, and Money) in an article entitled “Survey: iPhone retention 94% vs. Android 47%.” The data were collected by asking people in food courts and baseball stadiums what their current phone was and what phone they planned to buy next. The data were collected in the summer of 2011. Below is a portion of the data:

Phone Keep Change Proportion
iPhone 58 4 0.94
Android 17 19 0.47

The article contains the strong caution: “It's only a tiny sample, so large conclusions must not be drawn.” This caution appears to be a welcome change from the overstating of findings typically found in the media. But has this report understated the importance of the study? Perhaps it is valid to draw some "large conclusions."


What do you think?

Is it possible to conclude the vast majority of iPhone owners in the population sampled plan to buy another iPhone or is the sample size too small to justify this conclusion?