## Instructions

Welcome to this statistics tutorial. This tutorial teaches you about a number of very useful statistical techniques based on a working example using real data supplied by your tutor. You could use these pages as reference, to look up a single topic if you wanted, but they are designed to be worked through in order for a full understanding of the topics.

Each topic is divided into three levels and each level has three sections:

• Level 1 is designed to help you understand the statistics that you see reported in journal papers or that your statistics software package gives you. At this level, you will not calculate any statistics yourself, and there are no formulae. The emphasis is on understanding what the statistics measure, how to interpret them, and when to use them.
• Level 2 is about calculating the statistics. Here you will see the formulae for doing the calculations
• Level 3 covers the theory behind the techniques. Understanding the theory will give you a good intuitive feel for what the statistical measures that we cover are doing.
You can stay at one level, or switch up or down a level at any time. You are currently at level 2.

Each level of each topic is split into three sections, all shown on the same page. The sections are organised as they are below on this page. Move between topics and levels using the navigation box below. It appears at the top of every page in the tutorial. There are also next page and previous page links at the bottom of each page, which you can use to follow the topics in their suggested order.

 Getting Started General Instructions | Introduction to Your Study Descriptive Statistics Histograms | Scatter Plots | Central Tendency | Standard Deviation | Confidence Intervals Relating Variables Correlation Important Concepts The Normal Distribution | Z Scores | Probability Distributions Levels You are currently on Instructions at level 2. Level 1 | Level 2 | Level 3 Next Topic Start over | Introduction to Your Study

### Explanation

The Explanation section describes the concepts behind a technique or statistical measure. This section is designed to give you the facts much like a textbook would.

At the second level, it explains in words how the statistic is calculated

### Exploration

The Exploration section allows you to explore the concepts explained above for yourself.

At the second level, you are shown the formula or procedure for calculating the statistic. Hover over any part of the formula to see an explanation of what it means. For example, here is the formula for calculating the mean of a set of numbers.

Try it now with the formula above.

### Application

This tutorial is based on a set of data and an experiment taken from your own field of study.

The Application or Interpretation section uses this data, and the study that generated it, to allow you to try out each statistical technique on real data.

At the second level, you must calculate the statistics for that data yourself.

You will be asked to answer questions and be given feedback as you go. The questions look like this: What is 1+1?

The flat line next to the box for the answer shows that you have not yet answered the question. When you get the answer right, it turns into a tick and if you get the answer wrong, it becomes a cross. When you have typed an answer, click anywhere on the screen or press the TAB key (don't press the Enter key) to have your answer checked. So, the question above is 'What is 1+1?'. Try typing a wrong answer and then a right answer into the box.

The question mark in a circle is the help button. Hover over it to get a clue about answering the question.

 Start over | Introduction to Your Study