GCSE Statistics Key concepts / words

Question	Answer
Sampling Types?	Random Systematic Stratified Quota Cluster
Comparing two distributions	Use your ASS: - Compare AVERAGES (use proper word, e.g. mean, median) - Compare SPREADS (standard deviation or Inter-Quartile Range and overall range) - Compare SKEW (positive, negative, symmetrical)
Census vs Sampling	Census means: survey the whole population, which is EXPENSIVE, takes a LONG TIME and is DIFFICULT to deal with. But at least EVERYONE/EVERYTHING is taken into account. Sample means: pick some people or things to represent the whole population - this is QUICKER, CHEAPER, EASIER. However, it might not be fully representative.
Good and bad questions	A question is bad if: - it is biased / leading,e.g. "do you agree that MathsWorld is fantastic?" - it is open, i.e. has no response boxes - the options overlap, e.g. 1-2, 2-3 - there is no time limitation, e.g. "how many hours of sport do you play?" - it is vague, overcomplicated, or asks more than one thing, e.g. "How would you feel about a new shopping centre and how often do you think you'd go?"
Cumulative Frequency	Means RUNNING TOTAL When drawing the graph, plot the end of each group against the frequency

Resource summary

	Created by Felix Ulrich-Oltean almost 10 years ago