Against All Odds: Inside Statistics
Interactive: Wafer Thickness
Unit 1 What Is Statistics?
Statistics is the art and science of gathering, organizing, analyzing and drawing conclusions from data. And without rudimentary knowledge of how it works, people can't make informed judgments and evaluations of a wide variety of things encountered in daily life.
Unit 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.
Unit 3 Histograms
Meteorologists use histograms to map when lightning strikes and this visualization technique helps them understand the data in new ways.
Unit 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.
Unit 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.
Unit 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.
Unit 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.
Unit 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.
Unit 9 Checking Assumption of Normality
Production at Pete and Gerry's Organic Eggs provides a number of distributions that look normal — but are they?
Unit 10 Scatterplots
Plotting annual numbers of Florida powerboat registrations and manatee killings suggests an uncomfortable relationship for the marine mammals.
Unit 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.
Unit 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.
Unit 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.
Unit 14 The Question of Causation
This historical story describes how researchers untangled the relationship between smoking and lung cancer.
Unit 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.
Unit 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.
Unit 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.
Unit 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.
Unit 19 Probability Models
Casinos are as well versed in probability as statisticians and probability models help them maintain the house advantage over gamblers.
Unit 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?
Unit 21 Binomial Distributions
Sickle cell disease is an example of binomial distribution in families with two parents who are carriers for this genetic trait.
Unit 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.
Unit 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.
Unit 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.
Unit 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.
Unit 26 Small Sample Inference for One Mean
A brewer uses this technique to monitor quality differences in multiple batches of the same beer.
Unit 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.
Unit 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.
Unit 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.
Unit 30 Inference for Regression
Historical story of how statisticians built the case against DDT as the culprit behind plummeting peregrine falcon population numbers.
Unit 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.
Unit 32 Summary
This review of the course through the preceding 31 video modules provides an overview of the practice of statistics and helps students appreciate how statistical methods can help them better understand their world.
Interactive 34 Interactive: Stemplots
The Stemplots tool organizes data — either your own input or randomly generated — into a stemplot.
interactive 35 Interactive: Wafer Thickness
The Wafer Thickness tool generates data (represented as a histogram)