1.0 Practical Skills Definitions Flashcards
Absolute Uncertainties
The interval that a value is said to lie within, with a given level of confidence.
Accuracy
A measure of how close a measurement is to the true value.
Analogue Apparatus
Measuring apparatus such as rulers, beakers and
thermometers that rely on the experimenter reading off a scale to determine the measurement.
Anomalies
Data points that don’t fit the pattern of the data. You should determine why an anomalous result has occurred before removing it. Repeat readings help
remove anomalies.
Control Variables
Variables that must remain the same throughout an
experiment so as to not affect the results.
Dependent Variables
The variable being measured in an experiment. It is
dependent on the independent variable. The dependent variable should be plotted on the y-axis of a graph.
Digital Apparatus
Measuring apparatus such as ammeters, voltmeters and digital calipers that digitally measure and display measurement.
Fiducial Marker
A thin marker, such as a splint, that is used to ensure readings are taken from the same place each time. They are used to improve the accuracy of measurements
Independent Variables
The variable that is changed by the experimenter in an experiment. The independent variable should be plotted on the x-axis of a graph.
Precision
A measure of how close a measurement is to the mean value. It only gives an indication of the magnitude of random errors, not how close data is to the true value.
Random Errors
Unpredictable variation between measurements that leads to a spread of values about the true value. Random error can be reduced by taking
repeat measurements
Repeatable
The same experimenter can repeat a measurement using the same method and equipment and obtain the same value.
Reproducible
An experiment can be repeated by a different experimenter using a different method and different apparatus, and still obtain the same results.
Resolution
The smallest change in a quantity that causes a visible change in the reading that a measuring instrument records.
Systematic Errors
Causes all readings to differ from the true value by a fixed amount. Systematic error cannot be corrected by repeat readings, instead a different technique or apparatus should be used.
