what does accurate mean ?
Close to the true acceptable value
What does precise mean?
Results that are close together
What does repeatable mean?
When repetition under the same conditions (same experimenter) gives similar results
What does valid mean?
A suitable method is being used to answer the question being asked (to test the suitable hypothesis)
What does reproducible mean?
When similar results are produced by different laboratories and therefore by different experimenters using different pieces of equipment.
Percentage change calculation?
Percentage change = new quantity - original quantity/ original quantity X 100
error( uncertainty calculation
Absolute uncertainty/ quantity measured x100
Percentage uncertainty calculation
2x absolute uncertainty/ quantity measured x100
What is a systematic error ?
an error due to measured value differing from the true value by the same amount each time
What’s a random error
an error in measurement due to small uncontrollable effects - one off mistakes
