Practical Skills - Key Terms Flashcards
When is a measurement valid?
When it measures what it is supposed to be measuring
When is a result accurate?
When it is close to the correct value
What are precise results?
Repeat results that are consistent / close to each other
Repeatability
How precise repeat measurements taken by the same person, using the same equipment and conditions are
Reproducibility
How precise repeat measurements taken by different people with different equipment are
What is the uncertainty of a measurement?
The interval within which the true value is expected to lie
Measurement error
Difference between the true and measured values
What type of error is caused by results varying randomly and unpredictably around the true value?
Random error
What is a systematic error?
A consistent difference between the measured and true values
Define zero error
When a piece of measuring equipment gives a false reading when the true value should be zero
What variable is changed / selected by the investigator?
Independent variable
What variable is measured by the investigator?
Dependent variable
Define a fair test
A test in which the dependent variable is only affected by the independent variable
What are control variables?
Variables that should be kept constant, to avoid interfering with the dependent variable
