Against All Odds: Inside Statistics

Episode 2

Stemplots

As a first step in visualizing data, we use stemplots to understand measurements taken by the U.S. Army when they size up soldiers in order to design well-fitting gear and supplies for modern warfighters.

Episode 3

Histograms

Meteorologists use histograms to map when lightning strikes and this visualization technique helps them understand the data in new ways.

Episode 4

Measures of Center

It's helpful to know the center of a distribution — which is what the clerical workers in Colorado Springs found out in the 1980s when they campaigned for comparable wages for comparable work. Mean and median are two different ways to describe the center.

Episode 5

Boxplots

Using the example of hot dog calorie counts, we use boxplots to visualize the five-number summary and make comparisons between different types of frankfurters.

Episode 6

Standard Deviation

How can we compare sales at two franchises in the Wahoo's restaurant chain? Standard deviation helps us quantify the variability in sales.

Episode 7

Normal Curves

A nature preserve that's tracked bird migrations through New England for decades records tons of bird-related data; everything from wingspan measurements to arrival dates provides examples of normal distributions.

Episode 8

Normal Calculations

Visit the Boston Beanstalks club for tall people. Height is normally distributed and we can use membership cutoffs and population data to calculate z-scores.

Episode 9

Checking Assumption of Normality

Production at Pete and Gerry's Organic Eggs provides a number of distributions that look normal — but are they?

Episode 10

Scatterplots

Plotting annual numbers of Florida powerboat registrations and manatee killings suggests an uncomfortable relationship for the marine mammals.

Episode 11

Fitting Lines to Data

Winter snowpack in the Colorado Rockies can predict spring water supply. Plotting annual measurements in a scatterplot lets resource managers draw a regression line that helps them forecast water availability.

Episode 12

Correlation

Twin studies track how similar identical and fraternal twins are on various characteristics, even if they don't grow up together. Correlation lets researchers put a number on it.

Episode 13

Two-Way Tables

One city surveyed the happiness of its residents. Two-way tables help organize the data and tease out relationships between happiness levels and opinions about aspects of the city itself.

Episode 14

The Question of Causation

This historical story describes how researchers untangled the relationship between smoking and lung cancer.

Episode 15

Designing Experiments

We move beyond observational studies — like one of marine life in the remote Line Islands — to designing experiments that manipulate various subject groups — as in the case of a medical study about osteoarthritis treatments.

Episode 16

Census and Sampling

The U.S. counts every resident every ten years — or at least tries to. Statisticians use sampling from a population as an alternative to a complete count, as utilized at a potato chip factory.

Episode 17

Sample and Surveys

A visit to the University of New Hampshire Survey Center illustrates how pollsters create accurate surveys. They can then use details from their sample to make inferences about a whole population.

Episode 18

Introduction to Probability

Probability is the mathematics of chance behavior — and can help predict events such as the daily weather, or whether an asteroid will collide with Earth.

Episode 19

Probability Models

Casinos are as well versed in probability as statisticians and probability models help them maintain the house advantage over gamblers.

Episode 20

Random Variables

The Challenger space shuttle disaster was blamed on faulty O-rings. How can probability calculations on random variables help predict the chances of this kind of failure?

Episode 21

Binomial Distributions

Sickle cell disease is an example of binomial distribution in families with two parents who are carriers for this genetic trait.

Episode 22

Sampling Distributions

Heights of third graders in one class. Quality scores for circuit boards at a factory. Taking multiple samples allows us to visualize the sampling distribution of the sample mean.

Episode 23

Control Charts

This quality control method helped Quest Diagnostics streamline and improve their system for processing and testing lab samples so they could meet their nightly deadlines.

Episode 24

Confidence Intervals

A battery manufacturer tests just a sample of its product to verify its claims about battery life. A margin of error and a confidence level help quantify its accuracy.

Episode 25

Tests of Significance

Is a newly-discovered poem really written by William Shakespeare? Using statistical analysis of his known word use, researchers set up null and alternative hypotheses to investigate.

Episode 26

Small Sample Inference for One Mean

A brewer uses this technique to monitor quality differences in multiple batches of the same beer.

Episode 27

Comparing Two Means

Comparing the activity and calorie expenditure levels of Western office workers and African hunter gatherers adds some surprising new data to the science of obesity.

Episode 28

Inference for Proportions

Managers have no clue what conditions actually motivate their workers best, as shown by research conducted by Teresa Amabile, host of the original Against All Odds.

Episode 29

Inference for Two-Way Tables

Host Dr. Pardis Sabeti's own research examines possible genetic resistance to deadly Lassa fever in West Africa. Using Inference for Two-Way Tables helps untangle potential relationships.

Episode 30

Inference for Regression

Historical story of how statisticians built the case against DDT as the culprit behind plummeting peregrine falcon population numbers.

Episode 31

One-Way ANOVA

Does holding a heavier clipboard make you estimate that a jar of coins has more money in it than if you're holding a lighter clipboard? Psychologists use One-Way ANOVA to analyze the data from this experiment.

Episode 32

Summary

This review of the course through the preceding 31 modules provides an overview of the practice of statistics and helps students appreciate how statistical methods can help them better understand their world.