General skills for Biology

Accuracy

• Your investigation must provide accurate data 
• Some can calculate a theoretical value and chaeck against the experimental evidence
• You can draw a graph of results and see how close each result is to the line of best fit
• Try repeating measurements and check the spread or range within sets of repeat data.

Precision

• Your investigation must provide data with sufficient precision
• If it doesn't then you won't be able to make a valid conclusion.
• Repeat the tests each time in exactly the same way.

Evaluation

• Results will differ because of random errors
• Take precise repeat readings.

• Your graphs are designed to show relationships between your 2 chosen variables
• Consider what this means for your conclusion
• Must take into account the repeatability and reproducibility of data you are considering
• Continue to have an open mind about conclusion
• Will have made a prediction which could be supported by results or not
• Must be willing to think about your results- very rare for a set of results to completely support a prediction
• Look for possible links between variables
• The purpose of the predictiom was to test a hypothesis.It can: be supported, be refuted, lead to another hypothesis
• You have to decide which it is on available evidence

Start by representing the calculations as a fraction:

• Divide by original x 100 = percentage
• Difference / original x 100 = percentage change

Percentage decrease = actual decrease ÷ original value x 100

Percentage Increase = actual increase / original value * 100