# ISA Prep

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Accuracy
A measurement result is considered to be accurate if it is judged to be close to the true value.
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Calibration
Marking a scale on a measuring instrument. E.g. Placing a thermometer in melting ice to see whether it reads zero; to check if it has been calibrated correctly. Correcting equipment.
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Data
Information; either quantitative or qualitative, that has been collected.
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Errors/Uncertainties
The interval within which the true value can be expected to lie; with a given level of confidence or probability e.g. the temp. is 20C +/- 2C at a level of confidence of 95%.
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Measurement Error
The difference between a measured value and the true value.
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Anomalies
These are values in a set of results which are judged not to be part of the variation caused by random uncertainty.
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Random Error
Cause readings be spread about true value; due to results varying in an unpredictable way. Present when any measurement is made; and cannot be corrected. Effect can be reduced by making more measurements+calculating mean [EXPLAIN HOW MEAN CALCULATED]
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Systematic Error
Causes readings to differ from the true value by a consistent amount each time a measurement is made. Sources can include environment; methods of observation and instruments used.
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Zero Error
Any indication that a measuring system gives a false reading when the true value of a measurement quantity is zero; e.g scales not returning to zero when nothing on them. May result in systematic uncertainty.
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Evidence
Data which has been shown to be valid.
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Fair Test
A fair test is one in which only the independent variable has been allowed to affect the dependent variable.
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Hypothesis
A proposal intended to explain certain facts or observations.
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Interval
The quantity between readings e.g. a set of 11 readings equally spaced over a distance of 1 metre would give an interval of 10 centimetres.
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Precision
Precise measurements are ones in which there is very little spread about the mean value. Precision depends only on the extent of random errors-it gives no indication of how close results are to the true value..
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Prediction
A statement suggesting what will happen in the future, based on observation, experience or a hypothesis.
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Range
The maximum and minimum values of the independent and dependent variables; important in ensuring that any pattern is detected. E.g. from 10cm to 50 cm or from 50cm to 10cm.
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Repeatable
A measurement is repeatable is the original experimenter repeats the investigation using the same method and equipment and obtains the same results.
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Reproducible
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.
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Resolution
This is the smallest change in the quantity being measured (input) of a measuring instrument that gives a perceptible change in the reading.
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Sketch Graph
A line graph; not necessarily on a grid; that shows the general shape of the relationship between two variables. It will not have any points plotted and although the axes should be labelled they may not be scaled.
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True Value.
This is the value that would be obtained in an ideal measurement.
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Validity
Suitability of investigative procedure to answer question being asked. E.g.investigation to find out if rate of chemical reaction depended upon concentration of one of reactions would not be valid procedure it temp of reactants was not controlled.
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Valid Conclusion
A conclusion supported by valid data; obtained from an appropriate experimental design and based on sound reasoning.
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Categoric Variable
Have values that are labels. E.g. names of plants or types of material.
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Continuous.
Can have values (called quantity) that can be given a magnitude either by counting (e.g. no of shrimp) or by measurement (e.g. light intensity; flow rate etc)
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Control
One which may; in addition to the independent variable; affect the outcome of the investigation and therefore has to be kept constant or at least monitored.
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Dependent
The variable of which the value is measured for each and every change in the independent variable.
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Independent
The variable for which values are changed or selected by the investigator.
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## Other cards in this set

### Card 2

Calibration

#### Back

Marking a scale on a measuring instrument. E.g. Placing a thermometer in melting ice to see whether it reads zero; to check if it has been calibrated correctly. Correcting equipment.

Data

### Card 4

#### Front

Errors/Uncertainties

### Card 5

#### Front

Measurement Error