Mathsy/general important stuff

Question 1

What is accuracy?

Answer 1

how close you observed or measured value is to the correct/real value

Question 2

How can you improve accuracy?
Give an example

Answer 2

changing the experimental technique

e.g. ensure you use the most appropriate size of quadrat in transect measurements. Applies to any equipment really

Question 3

What is reliability?

Answer 3

the consistency in (or your confidence with) a set of measurements

Question 4

How can you improve reliability?

Answer 4

repetition - if repeated results lie close together then the results have high reliability

• taking repeat measurements also helps you identify and omit anomalous results

Question 5

How can you comment on reliability?

Answer 5

• considering spread of results
• considering the closeness of replicates to the mean
• calculating variance, standard deviation, standard error or 95% confidence intervals
• considering the size of range bars or error bars on graphs

Question 6

What is validity?

Answer 6

whether a test actually measures what it sets out to measure

Question 7

How can you comment on validity/improve validity?

Answer 7

• identify factors that are not or cannot be controlled and which may therefore be limiting the validity of the investigation