Key Words

Question 0

What’s a dependent variable?

Answer 0

In an experiment, what the effect or output is. What is measured.

Question 1

What’s a hypothesis?

Answer 1

An idea or proposal to explain certain facts or observations. Based on observations.

Question 2

What’s an independent variable?

Answer 2

In an experiment, what is changed and isn’t usually affected by the other variable.

Question 3

What’s a control variable?

Answer 3

Factors which are kept the same in an experiment.

A variable that is kept constant prat least monitored to minimise its impact of the dependent variable.

Question 4

Accuracy

Answer 4

How close a result is to the true value

Question 5

Calibration

Answer 5

Establishing the relationship between scales on a measuring instrument and what the true value should be e.g. Placing a thermometer in melting I to see whether it reads zero to check it calibrated correctly.

Question 6

Data

Answer 6

Information, either qualitative or quantitative, that has been collected.

Question 7

Measurement error

Answer 7

The difference between a measured value and the true value.

Question 8

Random error

Answer 8

The varying of results in an unpredictable way from one measurement to the next.
Random errors cannot be corrected but their eft can be reduced by carrying out repeats and calculating a mean.

Question 9

Systematic error

Answer 9

Caused by things such as the environment, instruments used and methods of observation, these cause readings to differ from the true value by a consistent amount each time a measurement is made.

Question 10

Zero error

Answer 10

Any indication that a measuring system gives a false readings hen the true value of a measured quantity is zero
E.g. The needle on an ammeter failing to return to zero when no current flows.

Question 11

Anomalies

Answer 11

Values in a set of results that are judged to deviate from the normal or common order, for or rule.

Question 12

Evidence

Answer 12

Data that has been shown to be valid.

Question 13

Fair test

Answer 13

A test where only the independent variable has been allowed to affect the dependent variable. All other variables have been controlled.

Question 14

Interval

Answer 14

The quantity between readings e.g. A set of a set of 10 readings equally spaced over a distance of 1 meter would give an interval of 10 cm

Question 15

Precision

Answer 15

Measurements that aren’t spread far from the mean value.

Question 16

Prediction

Answer 16

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

Question 17

Range

Answer 17

The maximum and minimum values of the independent or dependent variables, important in ensuring that any pattern is detected e.g. A range of distances may be “from 10 to 50 cm”.

Question 18

Repeatable

Answer 18

If the investigation can b repeated by the same person using the same method and equipment and obtain the same result.

Question 19

Reproducible

Answer 19

If the investigation can be repeated by another person or by using different equipment or techniques and they still obtain the same results.

Question 20

Resolution

Answer 20

The smallest change in the quantity being measured off of a measuring instrument e.g. +/- 0.01

Question 21

Sketch graph

Answer 21

A basic graph, not necessarily on a graph, that shows the general shape of the relationship between the two variables.
Points aren’t plotted and although axes are labelled they’d may not be scaled.

Question 22

True value

Answer 22

The value that would be obtained in an ideal measurement with no errors.

Question 23

Uncertainty

Answer 23

The interval within which the true value can be expected to lie with a given level of confidence or probability e.g. The temperature is 20’C +/- 2’C at a level of confidence of 95%.

Question 24

Validity

Answer 24

The suitability of the investigation to answer the question being asked e.g. An investigation to find out if the rate of a chemical reaction depended on the concentration of one of the reactants would not be valid if the temperature of the reactants was not controlled.

Question 25

Valid conclusion

Answer 25

A conclusion supported by valid data obtained from an appropriate experimental design and based on sound reasoning.

Question 26

Variables

Answer 26

Physical, chemical or biological quantities or characteristics that are subject to change

Question 27

Categoric variable

Answer 27

A variable that has values that are labels e.g. Names of plants or types of material

Question 28

Continuous variable

Answer 28

A variable where any value can be recorded, including fractions, over a defined range e.g. Counting the number of heartbeats per minute or measuring the light intensity in different locations.