statistics and probability

Vocabulary flashcards covering key statistical concepts, data classification types, data sources, and sampling methods from the 'Collecting and Classifying Data' notes.

Variable

Something measurable or observable in statistics that is expected to change over time or between individual observations.

Numerical (Quantitative) data

Data consisting of numbers that can be classified as either discrete or continuous.

Discrete numerical data

Data that can only take on particular numerical values that are counted, such as the number of TV sets in a house ($0$, $1$, $2$, $3$).

Continuous numerical data

Data that can take any value in a range, such as heights ($172\,\text{cm}$, $172.4\,\text{cm}$), weights, and temperatures.

Categorical data

Data that are not numerical, typically coming from survey answers given as words (such as colours, gender, or car brands) or ratings ($1 = \text{dislike}$, $2 = \text{neutral}$, $3 = \text{like}$).

Primary source

First-hand information collected directly from the original source by the person or organisation needing the data, such as a student conducting their own survey.

Secondary source

Data that have been collected, published, and possibly summarised by someone else before use, such as newspaper articles, textbooks, or internet blogs.

Census

A study or survey where an entire population is surveyed, such as an entire maths class, all the cars in a car park, or a whole country.

Sample

A subset of the population surveyed that should be randomly selected and large enough to represent the views of the overall population.

Observation

A method of gathering data used when researchers cannot choose which members of the population to survey and can record only those who present themselves.