AQA GCSE Statistics key terms

Data representing measurements that can take any value within a range, such as height or mass.

A time-series chart showing a statistic from successive samples, together with limits used to decide whether the production process needs checking or correcting.

A comparison group that does not receive the treatment being investigated.

A pattern of association between two variables, in which their values tend to vary together.

A number between −1 and 1 describing the direction and strength of a particular type of relationship between two variables.

The degree to which two variables follow a consistent pattern together. For a straight-line relationship, points clustered closely around a line show stronger correlation.

The number of births during a stated period per specified number of people in the total population, commonly per 1000 people.

The number of deaths during a stated period per specified number of people in the total population, commonly per 1000 people.

A rate calculated for a whole population without adjusting for differences in its composition, such as its age distribution.

A running total of frequencies up to a particular value or class.

A cumulative frequency graph for discrete data, with vertical jumps at possible data values and horizontal sections between them.

One complete repetition of a recurring pattern in data.

A pattern of rises and falls that repeats over time; its cycle need not be a year.

Recorded observations or measurements collected for an investigation.

Organising, representing and summarising data to identify patterns or make comparisons.

Checking data and dealing with errors or unnecessary notation so that it is suitable for analysis.

A restriction that limits how data can be collected or obtained, such as cost, time or access.

A change or flaw in collected data that makes it give a misleading picture of what is being investigated.

A mistake made when measuring, collecting, entering or recording data.

Organising, summarising and calculating with collected data so that it can help answer an investigation question.

A table, chart, graph or diagram used to communicate data and make features such as patterns or comparisons easier to see.

The number of deaths during a stated period relative to the population, commonly expressed as deaths per 1,000 people per year.

One of the nine dividing values that split ordered data into ten approximately equal parts. The $k$th decile is the $(10k)$th percentile.

Numerical data that takes separate possible values, such as the number of pets someone owns.

The pattern of values in a dataset, including where they cluster and how widely they are spread.

The point $(\overline{x},\overline{y})$, whose coordinates are the mean of the x-values and the mean of the y-values.

A bar chart with two bars side by side for each category, comparing two data sets on the same scale.