# Fathom Tutorials

These tutorials introduce you to all the features of Fathom in a variety of contexts. They’re written assuming that they would be done in order, gradually working through the all of Fathom's functions. You may choose to use the tutorials differently—jumping from topic to topic, for example—but note that in later tutorials, you will need to know the basics that were covered in the first tutorials.

Consider doing a couple of tutorials, and then using Fathom for a while to get used to the basics before doing later tutorials.

#### Exploring Data—Census at Schools

CensusAtSchool is an international project that collects data about students from the United Kingdom, South Africa, Australia, and New Zealand.

In this tutorial, you’ll use Fathom to start exploring the data. You’ll learn how to navigate around Fathom and how to make and use graphs.

#### Data and Prediction—Arm Span

This tutorial focuses on relationships between numeric data and linearity. Do taller people have bigger wrists? How is height related to arm span or other kinds of bone-length measurements? Which measurements allow us to best predict someone’s arm span?

#### Importing U.S. Census Microdata

Using Fathom, you can import samples of census microdata from 1850 to 2000. You can use these data to explore many characteristics of the American people.

#### Using Formulas to Explore the Planets

In this tutorial, you'll learn to use formulas to define new attributes and to plot functions. You'll compute the density of the planets in our solar system, and investigate the relationship between a planet’s distance from the sun and the length of its year.

#### Generating Mathematics—Change Playground

This tutorial also focuses on using formulas to define new attributes, but this time you'll work in a purely mathematical context, learning how to calculate change using Fathom’s "prev" function.

#### Simulation—Polling Voters

In this tutorial, you'll simulate a population of voters, a certain proportion of whom will vote in favor of a particular proposition. You'll see how accurately a random sample of voters can predict the outcome of an election.

#### Testing a Hypothesis—Plant Growth

In this tutorial, you'll learn to use a t-test in the context of a classic Darwin experiment involving growing snapdragons and measuring their heights.

#### Testing for Independence—Pets and Sports

This tutorial is not for the faint of heart. You'll combine classic statistical inference techniques with a computer-intensive method called scrambling. You'll simulate the null hypothesis to generate a distribution, and you'll plug the data into a chi-square test for independence. You should be familiar with basic Fathom techniques.

#### Numerical Integration—The Elevator Experiment

Sometimes the purpose of gathering data is to compute some quantity from the data. In this tutorial, you’ll use data supplied by a force probe to find the distance traveled.

#### Classroom Survey

When making a survey, it’s helpful to start with an investigative purpose rather than a laundry list of questions. In the classroom you might brainstorm conjectures students would be interested in testing. In this tutorial, you’ll design a survey to test the conjecture that girls spend more time on the telephone and boys spend more time watching TV.

#### Typing Tutor Experiment

Have you ever wondered which keys on a computer keyboard give you the most trouble? For example, which ones take you the longest to reach? In this tutorial, you'll use Fathom to find out. You’ll turn a collection into an experiment that records which keys you type and how long it takes you to type them.

#### How Fast Do You Walk?—Measuring Distance with Sensors

In this tutorial, you'll gather data from a motion sensor. You'll then construct a mathematical model of the physical situation.

#### Cooling Water—Measure Temperature Over Time

In this tutorial, you'll gather data from a temperature sensor. As the data are being gathered, you'll construct a mathematical model of the physical situation and determine whether the model fits the data.

#### Timing with Photogates

Suppose you want to measure precisely how long it takes an object to travel a certain distance. You could use a stopwatch, but you would have a lot of reaction-time error. When a photogate’s light is blocked, it triggers a timer with an error of less than a millisecond. In this tutorial, you’ll set up a pair of photogates to make this measurement.