A2 3: Practical Skills in A2 Biology

What A2 3 covers

• Designing investigations with valid controls
• Precision, accuracy and sources of error
• Statistical treatment of biological data
• Drawing conclusions and evaluating method limitations

Assessment: Assessment of practical skills — practical booklet work completed in class and a written practical-skills paper. The definitive content statements are published by CCEA at ccea.org.uk.

Where marks get lost

• Choosing the wrong statistical test for the data type (correlation vs difference vs association).
• Quoting a result as 'significant' without referencing probability and the critical value.
• Evaluations that list generic errors instead of ones specific to the apparatus used.

Question styles to drill

• Selecting and justifying a statistical test from a short data description.
• Calculating standard deviation or standard error and interpreting error bars.
• Explaining whether the data support the hypothesis, using the numbers given.

Other CCEA A2 units

• A2 1 · Physiology, Co-ordination and Control, and Ecosystems
• A2 2 · Biochemistry, Genetics and Evolutionary Trends