Chapter 3 – The Little Figures That Are Not There

The chapter emphasizes the importance of scrutinizing what is not presented in statistics, as the absence of certain figures can be just as misleading as the presence of manipulated data.

Key Points:

• Incomplete Data: Statistics often omit crucial details, such as the sample size or the methodology used to collect the data. Without this information, it’s impossible to gauge the validity and reliability of the findings. A small sample size or a biased methodology can easily skew results. For example, a school district reports a significant improvement in standardized test scores over the past year. The average score increased by 10%, which seems like a substantial achievement. However, the report fails to mention that the number of students taking the test decreased significantly. It turns out that many low-performing students were excluded from taking the test this year, leading to an artificially inflated average score.
• Misleading Comparisons: Statistics may compare data points that are not truly comparable, leading to inaccurate conclusions. For example, comparing crime rates between cities without considering differences in population size, demographics, or law enforcement practices can be highly misleading.
• Hidden Costs: Some statistics may focus solely on the benefits of a particular product or policy while conveniently ignoring the associated costs or negative consequences. This creates a false impression of the overall impact. For instance, a weight loss drug might be advertised as highly effective based on average weight loss, but the potential side effects or long-term health risks might be downplayed or omitted.
• Selective Reporting: Researchers or organizations may cherry-pick data that supports their desired narrative while omitting data that contradicts it. This can lead to a biased and inaccurate representation of the situation. For example, a study might highlight the positive effects of a new educational program on a select group of students while ignoring the lack of impact or even negative effects on other students.

The Importance of Critical Thinking:

The chapter emphasizes the importance of asking critical questions about the data presented, such as:

• What information is missing?
• How was the data collected?
• What is the sample size?
• Are the comparisons valid?
• Are there any hidden costs or negative consequences?

By being aware of these potential pitfalls and actively seeking out missing information, readers can become more discerning consumers of statistics and avoid being misled by incomplete or biased presentations.