The Scientific Method Flashcards
What is validity?
The extent to which a measurement, test, or study measures what it appears to measure.
What is a valid conclusion?
A conclusion supported by valid data, obtained from an appropriate experimental design and based on sound reasoning.
What is reliability?
The degree of stability exhibited when a measurement is repeated under identical conditions.
What are the three types of reliability?
- Repeatability
- Reproducibility
- Representativity
What is repeatability?
A measurement is repeatable if the original experimenter repeats the investigation using same method and equipment and obtains the same results.
What is reproducibility?
A measurement is reproducible if the investigation is repeated by another person, or by using different equipment or techniques, and the same results are obtained.
What is representativity?
A measurement is representative if the results can be generalised to a wider population.
What is a fair test?
A fair test is one in which only the independent variable has been allowed to affect the dependent variable.
What is bias?
Inclination or prejudice for or against one person/group/idea/belief, especially in a way considered to be unfair.
What is accuracy?
A measurement result is considered accurate if it is judged to be close to the true value
What is precision?
Precise measurements are ones in which there is very little spread about the mean value when you measure the same variable repeatedly with the same instrument. Precision depends only on the extent of random errors – it gives no indication of how close results are to the true value.
What is a true value?
This is the value that would be obtained in an ideal measurement.
What is uncertainty?
The interval within which the true value can be expected to lie, with a given level of confidence or probability.
What is resolution?
This is the smallest change in the quantity being measured (input) of a measuring instrument that gives a perceptible change in the reading.
What is the range?
The maximum and minimum values of the independent or dependent variables; important in ensuring that any pattern is detected.
What is an interval?
The quantity between readings.
What is calibration?
Marking a scale on a measuring instrument. This involves establishing the relationship between indications of a measuring instrument and standard or reference quantity values, which must be applied.
What is data?
Information, either qualitative or quantitative, that has been collected.
What is evidence?
Data which has been shown to be valid.
What is a hypothesis?
A proposal intended to explain certain facts or observations.
What is a prediction?
A prediction is a statement suggesting what will happen in the future, based on observation, experience or a hypothesis.
What are anomalies?
These are values in a set of results which are judged not to be part of the variation caused by random uncertainty.
What is a measurement error?
The difference between a measured value and the true value.
What is a random error?
These cause readings to be spread about the true value, due to results varying in an unpredictable way from one measurement to the next.
Random errors are present when any measurement is made, and cannot be corrected. The effect of random errors can be reduced by making more measurements and calculating a new mean.
