Practical Science Key Terms Flashcards
When is a measurement valid
It measures what it’s supposed to be measuring
When are results accurate
They’re close to the true value
What are precise results
Results are close to eachother
What is repeatability
Results taken by the same person, same equipment, under the same conditions.
How precise they are
What is reproductability
How precise measurements are when taken by different people with different equipment
What is the uncertainty of a measurement
Interval within which the true value is expected to lie
Measurement error
Difference between a measurement value and the true value
Random error
Results vary around the true value in an unpredictable way
Systematic error
Consistent difference between the measured values and true values
Zero error
Measurement instrument gives a false reading when the true value should be zero
Independent value
The value changed by investigator
Dependant variable
The variable that’s measured when the independent variable changes
Fair test
Only the independent variable can affect the dependant variable
Control variable
Variables kept constant to avoid them affecting the dependant variable
