GCSE Statistics (Edexcel) questions and
answers
What is raw data? - Unprocessed data that has just been collected and needs to
be ordered, grouped, rounded, cleaned.
What is qualitative data? - Non-numerical, descriptive data such as eye/hair colour
or gender. Often subjective so usually more difficult to analyse.
What is quantitative data? - Numerical data that can be measured with numbers.
Easier to analyse than qualitative data. Example, height, weights, marks in an
exam etc.
What is discrete data? - Data that only takes particular values (not necessarily
whole numbers) such as shoe size or number of people.
What is continuous data? - Data that can take any value e.g. height, weight.
What is categorical data? - Data that can be sorted into non-overlapping
categories such as gender. Used for qualitative data so that it can be more easily
processed.
,GCSE Statistics (Edexcel) questions and
answers
What is ordinal data? - Quantitative data that can be given an order or ranked on a
rating scale, e.g. marks in an exam.
What is bivariate data? - Data that involves measuring 2 variables. Can be
qualitative or quantitative, grouped or ungrouped. Usually used with scatter
diagrams where the two axes represent the two different variables.
What is multivariate data? - Data that is made up of more than 2 variables e.g.
comparing height, weight, age and shoe size together.
What does grouping data mean? - Grouping data using tables makes it easier to
spot patterns in the data and quickly see how the data is distributed.
What are the pros of grouping data? - Makes the data easy to read and
understand, easy to spot patterns and compare data.
What are the cons of grouping data? - Loses accuracy of data as you no longer
know exact data values. Calculations made from these will only be an estimate
e.g. mean.
,GCSE Statistics (Edexcel) questions and
answers
What is primary data? - Data that you have collected yourself, or someone has
collected on your behalf.
What is secondary data? - Data that has already been collected.
What is a population in the context of an investigation? - Everyone or everything
that could be involved in the investigation.
What is a census? - A survey of the entire population.
What is a sample? - A smaller number from the population that you actually
survey. The data obtained from the sample is then used to make conclusions
about the whole population.
What is a sampling frame? - A list of all the members of the population. This is
where you will choose the sample from.
What is a sampling unit? - The people that are to be sampled e.g. students in a
school.
, GCSE Statistics (Edexcel) questions and
answers
What is a biased sample? - A sample that does not represent the population fairly.
Example, if surveying students at a mixed school and the sample only contains
girls.
What is a random sample? - A sample where every item/person in the population
has an equal chance of being selected.
What are some random sampling techniques? - Pick numbers/names out of a hat,
using a random number table, using the random number generator function on a
calculator or computer.
What are the advantages of random sampling? - Sample is representative as every
member of the population has an equal chance of being selected. It's unbiased.
What are the disadvantages of random sampling? - Need a full list of population
(not always easily obtainable), not always convenient as it can be expensive and
time consuming, needs a large sample size.
What is a stratified sample? - A sample where the size of each strata (group) in the
sample is in proportion to the sizes of strata in the population.
answers
What is raw data? - Unprocessed data that has just been collected and needs to
be ordered, grouped, rounded, cleaned.
What is qualitative data? - Non-numerical, descriptive data such as eye/hair colour
or gender. Often subjective so usually more difficult to analyse.
What is quantitative data? - Numerical data that can be measured with numbers.
Easier to analyse than qualitative data. Example, height, weights, marks in an
exam etc.
What is discrete data? - Data that only takes particular values (not necessarily
whole numbers) such as shoe size or number of people.
What is continuous data? - Data that can take any value e.g. height, weight.
What is categorical data? - Data that can be sorted into non-overlapping
categories such as gender. Used for qualitative data so that it can be more easily
processed.
,GCSE Statistics (Edexcel) questions and
answers
What is ordinal data? - Quantitative data that can be given an order or ranked on a
rating scale, e.g. marks in an exam.
What is bivariate data? - Data that involves measuring 2 variables. Can be
qualitative or quantitative, grouped or ungrouped. Usually used with scatter
diagrams where the two axes represent the two different variables.
What is multivariate data? - Data that is made up of more than 2 variables e.g.
comparing height, weight, age and shoe size together.
What does grouping data mean? - Grouping data using tables makes it easier to
spot patterns in the data and quickly see how the data is distributed.
What are the pros of grouping data? - Makes the data easy to read and
understand, easy to spot patterns and compare data.
What are the cons of grouping data? - Loses accuracy of data as you no longer
know exact data values. Calculations made from these will only be an estimate
e.g. mean.
,GCSE Statistics (Edexcel) questions and
answers
What is primary data? - Data that you have collected yourself, or someone has
collected on your behalf.
What is secondary data? - Data that has already been collected.
What is a population in the context of an investigation? - Everyone or everything
that could be involved in the investigation.
What is a census? - A survey of the entire population.
What is a sample? - A smaller number from the population that you actually
survey. The data obtained from the sample is then used to make conclusions
about the whole population.
What is a sampling frame? - A list of all the members of the population. This is
where you will choose the sample from.
What is a sampling unit? - The people that are to be sampled e.g. students in a
school.
, GCSE Statistics (Edexcel) questions and
answers
What is a biased sample? - A sample that does not represent the population fairly.
Example, if surveying students at a mixed school and the sample only contains
girls.
What is a random sample? - A sample where every item/person in the population
has an equal chance of being selected.
What are some random sampling techniques? - Pick numbers/names out of a hat,
using a random number table, using the random number generator function on a
calculator or computer.
What are the advantages of random sampling? - Sample is representative as every
member of the population has an equal chance of being selected. It's unbiased.
What are the disadvantages of random sampling? - Need a full list of population
(not always easily obtainable), not always convenient as it can be expensive and
time consuming, needs a large sample size.
What is a stratified sample? - A sample where the size of each strata (group) in the
sample is in proportion to the sizes of strata in the population.
