AS and A Level Biology A - H020, H420: Do students need to know how to do chi squared tests (and all the other statistics)?

Yes. Please refer to the Mathematical Requirements section of the specification ‘M1.9 Select and use a statistical test’. 

These are all specified subject content by the DfE and almost all of them are required for both AS Level and A Level students. This applies to both OCR A and B specifications as well as Biology AS and A Levels from all the other awarding bodies.

(The only ‘A Level only’ skills are M0.5, M2.5 and M3.4. These do not appear at all in the AS specifications and appear in bold in the A Level specifications).

AS and A Level students must be able to select and use:

• Chi squared test (χ²)
• Unpaired t-test / student’s t-test
• Paired t-test
• Spearman’s rank correlation

Students do not need to memorise the formulae.

The Mathematical Skills handbook and Mathematical skills statistics booklet explains these tests with examples. There is also a section on Statistical tests in the Maths for Biology online resource.

https://www.ocr.org.uk/subjects/science/maths-for-biology/handling-data/

There is also a flowchart to help students choose the most appropriate test to use for a given data. Note that this flowchart will not be provided in the written exams.