Subject specific vocabulary: The language of measurement

Vocabulary flashcards covering key measurement concepts and terms from AS/A-level Science.

Accuracy

A measurement result is close to the true value.

Calibration

Marking a scale on a measuring instrument and establishing the relationship between readings and standard/reference values; e.g., checking a thermometer reads 0 °C in melting ice.

Data

Information, qualitative or quantitative, that has been collected.

Measurement error

The difference between a measured value and the true value.

Anomalies

Values in a data set not part of the variation caused by random uncertainty.

Random error

Errors that spread readings around the true value due to unpredictable variation; cannot be corrected but reduced by more measurements and averaging.

Systematic error

Errors that cause readings to differ from the true value by a constant amount; can arise from environment, methods, or instruments and are not fixed by repeats.

Zero error

Indication that a measuring system gives a false reading when the true value is zero (e.g., ammeter needle not returning to zero). May cause systematic uncertainty.

Evidence

Data that has been shown to be valid.

Fair test

A test in which only the independent variable affects the dependent variable.

Hypothesis

A proposal intended to explain certain facts or observations.

Interval

The quantity between readings; e.g., 11 readings across 1 metre give an interval of 10 cm.

Precision

Very little spread about the mean; depends on random errors and does not indicate closeness to the true value.

Prediction

A statement about what will happen in the future, based on observation, experience or a hypothesis.

Range

The maximum and minimum values of the variables; helps detect patterns (e.g., 10 cm to 50 cm or 50 cm to 10 cm).

Repeatable

A measurement is repeatable if the original experimenter repeats the investigation with the same method and equipment and obtains the same results.

Reproducible

A measurement is reproducible if another person or different equipment/techniques yield the same results.

Resolution

The smallest change in the quantity being measured that produces a perceptible change in the reading.

Sketch graph

A line graph showing the general shape of the relationship between two variables; may not be plotted on a grid and axes may not be scaled.

True value

The value that would be obtained in an ideal measurement.

Uncertainty

The interval within which the true value is expected to lie, with a given level of confidence.

Validity

Suitability of the investigative procedure to answer the question.

Valid conclusion

A conclusion supported by valid data, from appropriate experimental design and sound reasoning.