Mathematics and Statistics Support

We have a range of Jamovi video and paper resources on Getting started with Jamovi and carrying out statistical tests.

Summary Statistics and Graphs

We have a few resources on summarising data in SPSS but also recommend BrunelASK videos for a wider range in Excel or SPSS.

Testing Averages of Different Groups

These tests are used to compare the averages of completely different groups of people or subjects. Independent t-tests are for comparing two groups and ANOVA for 3+. ANCOVA allows a continuous covariate to be added.

Testing Averages of Paired or Repeated Measurements

If you have collected multiple measurements of the same variable e.g. weight before or after a diet,

Correlation and linear regression

Use these techniques when looking at relationships between continuous variables or the impact of several continuous or binary independent (predictor) variables on one continuous dependent (outcome) variable.

Testing Categorical (nominal) Data

If you have two categorical (nominal) variables, look for an association using Chi-squared test of association. If you dependent has only two categories (binary), you can test several binary or continuous predictors using logistic regression.

Non-parametric tests (ordinal or skewed data)

If your dependent variable is ordinal (e.g. strongly disagree - strongly agree) or your data are skewed, use a non-parametric test for comparing groups or repeated measurements.

Reliability

If you are using a mean or total score of a set of ordinal questions, use Cronbach's alpha to test for internal consistency. If you are testing for agreement between observers or methods, use Intraclass correlation for continuous and Kappa for categorical.

Choosing the right statistical test

We have summary self-help sheets on statsitical terminology for choosing the right test, summary tables and our interactive test chooser which takes you to the appropriate resource at the end.

Data manipulation in SPSS

We have a few resources on manipulating data in SPSS here but also recommend videos created by the stats support team at Brunel University on topics such as reverse coding, creating or reducing categories and creating a scale mean.

Practice Datasets

These data sets are used in the self-help resources in case you want to follow through the process.