Key Science Skills Flashcards
Positive & negative controls
Negative controls: Used to elicit no response. They help confirm that any positive result in the experiment is truly due to the test condition and not due to external factors.
Positive controls: Positive controls confirm that the experimental setup can detect positive results and that all reagents and instruments are functioning correctly and as intended.
Qualitative data
Nominal, ordinal
Quantitative
Discrete, continuous
Accuracy
Accuracy of measurement is how close the measured value is to its true value
Precision
Precision of measurement is how close each repeated measurement is to the other measurements
Personal errors
NOT considered a type of experimental error - e.g. miscalculations
Systematic error
A consistent error that occurs every time you measure something
Reducing systematic error
Involves selecting appropriate equipment, using calibrated equipment, using equipment correctly and controlling variables. Improves accuracy.
Random error
Unpredictable variations that can occur with each measurement.
Reducing random errors
Involves taking more measurements and increasing your sample size. Improves precision.
Repeatability
How close of consistent measurements are when conducted under the same conditions of measurement.
Reproducibility
How close or consistent measurements are when carried out under changed conditions of measurement.
Reliability
Sometimes called repeatability and is the ability to obtain the same results if the experiment is repeated. Kind of like precision.
Validity
Refers to whether your results are sound and can be generalized (are they measuring what they are supposed to be). Kind of like accuracy.
