GCSE Practical Science Resources

GCSE Science Revision Guides at Bangor University

Glossary of Terms

Term   Definition  
Independent variable The variable (factor) you choose to change in an investigation.
Dependent variable The variable (factor) which you measure every time you change the value of the independent variable.
Controlled variable A variable (factor) which may affect the results of the investigation and therefore should be kept constant.
Range The highest and lowest values of the independent variable. These should not be too big or too small.
Valid conclusion A conclusion (what you found out) supported by the results of data from a well-designed investigation and based on good scientific knowledge.
Validity of experimental design How good the method is to answer the question being asked. The method should include fair testing and controlled variables.
Resolution This is the smallest change in the quantity being measured by a measuring instrument that can be observed. For example, ± 1 mm on a 1 metre ruler.
Anomaly A value in a set of results which is seen to be much bigger or smaller than the rest of the values in the set.
True value This is the value that would be obtained in ideal conditions.
Uncertainty The range within which the true value can be expected, e.g. “the temperature is 20 °C ± 2 °C”. There is a formula to calculate this which you will be given in an exam.
Measurement error The difference between a measured value and the true value.
Systematic error A systematic error is normally caused by the apparatus used and causes readings to differ from the true value by the same amount each time. The effect of systematic errors cannot be reduced by increased repeats.
Random error This occurs when results vary unpredictably from one measurement to the next. These are normally due to errors by the person taking the measurements. The effect of random errors can be reduced by taking more measurements and calculating a mean.
Accuracy A measurement result is considered accurate if it is judged to be close to the true value.
Precision A set of precise measurements show very little spread about the mean value.
Repeatability The precision obtained when repeat readings are obtained by a single learner/ group.
Repeatable A measurement is repeatable, if a single learner/ group using the same method and equipment, obtains the same or similar results when they carry out the investigation again.
Reproducibility The precision obtained when repeat readings are obtained by a different learners/groups.
Reproducible A measurement is reproducible, if different learners/ groups obtain the same or similar results. This could include using different equipment/ methods.
Hazard A chemical or piece of apparatus that could cause harm. It is expected that in risk assessments the nature of the hazard is also specified. For example, ‘Hydrogen peroxide is an irritant’.
Risk A step in the method involving a hazard that might result in danger. For example, ‘Hydrogen peroxide could get onto the skin when pouring it into the measuring cylinder or the beaker’.
Control measures Something that can be done to reduce or prevent a risk while still allowing you to carry out the experiment. For example, ‘Wash hands immediately if any hydrogen peroxide gets onto them’.






Autumn Half Term Mathematics Revision Resources

Topics for mathematics examination additional to numeracy topics
Expanding two brackets (FOIL)
nth term of a linear sequence
Forming and solving simultaneous equations        (BBC Bitesize)
Using graphs to solve simultaneous equations
Factorising – Common factor method
Factorisation of quadratic expressions.
Trial and improvement
Forming and solving inequalities
Inequality graphs
Coordinates of a midpoint
Parallel and perpendicular lines
Knowledge of y = mx + c
Drawing and interpreting the graphs y= a/x, y = ax² +bx +c, y = ax³+ b, when y is given implicitly in terms of x
Probability of an event occurring/not occurring
Listing outcomes of up to two experiments
Venn diagrams
Relative frequency, representation using graphs
And/Or rules (mutually exclusive, independent)
Tree diagrams
Angles in quadrilaterals
Polygons : internal and external angles
Circle Theorems:
Tangent and radius meet at 90
Angle at centre is double than circumference
Angles in same segment are equal
Opposite angles in cyclic quadrilateral add to 180º
Angle subtended by semicircle is 90º
Tangents from external point are equal
Coordinates in all 4 quadrants
Symmetry – reflection and rotation
Centre of Rotation
Enlargements (including with a centre)
Enlargements with a fractional scale factor
Translation, using column vector
2 successive transformations
Construction of triangles, quadrilaterals and circles
Constructing angles of 60º, 30º, 90º and 45º.
Identifying congruent shapes

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