ExplanationIntroduction to Your StudyThroughout this tutorial, we will use real data from a real experiment to illustrate the topics that you will learn about.
This tutorial relates the salary cost in dollars for an HR representative to the number of employment applications processed.
We will use the vocabulary of statistics, which can be confusing if you haven't seen it before, so here is an introduction to the study you will be working through and the words that are used to describe it.
Statistics are designed to help us understand things we observe in the world around us. To use statistics, we have to measure things in the real world and so produce data. Data can be expressed as words or numbers, and are plural - so you say "Here are my data."
So that we know which aspects of the data we are talking about, we use the following words:
- To generate data we take measurements or make observations of specific qualities of things;
- The things we are measuring are called the experimental units of the study. They might be referred to as 'people' or 'soil samples', whatever is being measured, but in this study, they are referred to as Applications;
- The qualities that we measure, or observe, are called variables. So if you measured a piece of string, the string would be the experimental unit and 'length' would be the variable;
- All variables take a range of values - the variable 'length' might take the values 3 or 10.5, for example. Generally, one measurement of a variable from a single experimental unit will produce a single value. If we say "Length = 5" then 'length' is the variable and '5' is the value.
Your study measured two variables: Cost, measured in Dollars and No. Apps, measured in Applications
Your study is looking for a relationship between two variables. You want to know if, and how strongly no. apps and cost are related.