Statistics is all about reading patterns in the numbers. One of the easiest ways to read patterns is to look at a picture, or graph, of the data. In fact, it is so easy, it should be the first thing that you do as a part of any analysis. The most common type of statistical […]

# Descriptive Statistics

## Measures of Position Explained

What do you do when you’re lost? You use tools like a compass and GPS to figure out where you are and how to get where you are going. Well, in statistics there are ways to figure out where a data point or set falls. These are called measures of position. Once we know where […]

## Measures of Dispersion Explained

How normal is your data? I mean, does your sample seem to represent the population well? Does your data have a regular pattern? Is your data precise or vague? In statistics, we answer these questions using measures of central tendency and measures of dispersion. There are three big measures that help determine if your data […]

## What is Sampling Variability? And Why is it Important?

You can’t always get what you want, but if you try sometimes, you get what you need. In terms of statistics, we want to know everything that there is to know about a group (or population). But sometimes that is just not feasible. Instead, we deal with approximations of a smaller group (or sample) and […]

## Scatter Plots and Correlation

In statistics, you deal with a lot of data. The hard part is finding patterns that fit the data. To look for patterns, there are several statistical tools that help identify these patterns. But before you use any of these tools, you should look for basic patterns. You can identify basic patterns using a scatter […]

## Pearson Correlation Coefficient

While perusing books in the library, I was drinking a soda and wondered, “Do I read more books when I drink soda?” Now, I drink a lot of soda and I read a lot of books, but I don’t know if they are related. So, I asked a bunch of people how much soda they […]

## Understanding Measures of Central Tendency

I love to read. Of course, a lot of people do too; that is why there are bookstores after all. But when I go to the bookstore to buy a new book, I don’t read the entire book before I buy it. Instead, I read the synopsis and maybe a couple of reviews of the […]

## What is Effect Size? (And Why Does It Matter?)

I’m a tall guy at 6’3″ while my wife is little short at 5′. In fact, men have an average height of 70.00″ while women have an average height of 64.2″. It’s easy to see a difference in the means, but how different are they? Enter effect size, the measure of difference between two means. […]

## How are Quartiles Used in Statistics?

Quartiles are numbers that divide a data set into four-equal sized groups. Find out the uses of quartiles, how to find them, and why they are more useful than any single measure of center or spread!

## How to Make a Stem and Leaf Plot

One of the best and worst things about statistics is all the different ways that there are to represent data. There are histograms, box plots, and more. I mean, how are you supposed to choose which way to represent the data? One of the quickest ways to represent data is a stem and leaf plot. […]