# Regression

You may have studied regression in a statistics course years ago. Let’s refresh your memory, or teach you the basics so that you can properly use regression in your dissertation. We promise we will use only the most simple concepts.

**Definition**

In regression, you test your theory that something of interest (called the dependent variable or the outcome) is affected by one or more other entities of interest (called the independent variables or the predictors). Typically, a dissertation data set will have multiple independent variables.

*Note*. Regression can also be used to forecast the future based on trends. This specific type of regression is often used in economics and is called time-series regression.

**Examples**

*Simple Regression*

You can use simple regression to measure the effect of a single variable. An example would be seeing whether class size affects students’ test scores.

*Multiple Regression*

You can use multiple regression to measure the effect of more than one variable. An example would be seeing which of the following affect a teacher’s income: gender, years of education, years of teaching experience, or what grade the teacher teaches.

We present a writeup for the simple regression example.

**Writeup**

We run the regression for you in SPSS, make sure you understand it, and can write up the results formally in APA format, like this writeup for the above simple regression example:

Class size ranged between 10 and 37 students (*N* = 100; *M *= 24.27; *SD* = 5.08). Scores ranged between 10 and 84 (*N* = 100; *M* = 49.64; *SD* = 15.55). A simple regression analysis showed that class size significantly affects test scores. The smaller the class, the higher the test scores (*t* = -2.18; *p* < .05). The effect size (f^{2})was 0.05. Using Cohen’s (1988) conventions, this is a small effect.

Cohen, J. (1988). Statistical power analysis for the behavioral sciences. 2nd ed. Hillsdale, NJ: Lawrence Erlbaum.

To see your dissertation results written up just like this, contact us!

**Table in APA Format**

Reporting regression requires more than one table, but this is one of them, in APA format of course:

For theoretical help with your regression analysis, running it in SPSS, or deciding whether regression is the appropriate technique for your data, please contact us.