At SHS we use a piece of statistics software called Acastat Suite which can be run on any machine in the school. This is an easy-to-use package that can be downloaded for a thirty day free trial from here.
For a quick intro to entering data and preparing for an analysis go here.
Choosing Your Test
The most commonly used tests in AS and A2 coursework are correlation or regression anlysis and the t-test:
Regression and Correlation When you think you have a reasonable straight line relationship (ie you can draw a straight-ish line graph of your results) you would choose to do a regression or correlation analysis.
For a step by step guide to doing this in Acastat click here.
The t-test If you have a number of different treatments with replicates (eg if you have counted the number of organisms in quadrats in a few different areas on a beach,) you may want to discover if there are statistically significant differences in the average number when you compare different beach zones.
A t-test allows you to compare the mean effect of different pairs of tratments. For a step-by-step guide to t-tests using Acastat click here.
Entering data into Acastat The opening screen of Acastat is shown below:
Enter your data into separate columns.
Always label the column headers so your variables have names. They can be a maximum 8 letters long.
To label a cloumn, highlight a column and click on the Variable Format pulldown menu, then select Format Variables and type a name into the Variable Name box.
