Download GCSE Statistics Knowledge Planner

Data and Types of Data
Qualitative data
Quantitative data
Discrete data
Continuous data
Ranked data
Bivariate data
Rounding and
accuracy
Definition
Data that uses words
Data that uses numbers
Data that can be counted
Data that can be measured
Data that has been ranked
Data that has two variables
Example/ Information
Colours, foods,
Time, temperature, shoe size
Number of siblings
Height
Definition
All the people or objects you are
interested in
When you collect data from the
whole population
When you collect data from part of
the population
Data you collect yourself
Notes
Ice cream sales and temperature
Because continuous data is measured
you always have to decide on a level
of accuracy, you can use upper and
lower bounds to do this
Data Collection
Term
Population
Census data
Sample
Primary data
Secondary data
Pilot surveys
Data that is collected by someone
else
Is a preliminary survey used to
gather information prior to
conducting the survey
Questionnaires
A way of collecting data.
Interviews
A way of collecting data.
Statistical
experiments
Systematic sampling
Stratified sampling
Random sampling
Quota sampling
Cluster sampling
Start at a particular point in the data
and collect at a regular interval
Allows each group within the
population to be represented fairly
within the population.
Allows each person in the
population to have an equal chance
of being in the sample.
The people in the sample just have
to be of a particular type.
The population is split into smaller
group called clusters. One or more
clusters is chosen at random.
Make sure you know the advantages
and disadvantages
Make sure you know the advantages
and disadvantages
Usually used to see if your means of
collecting data is going to give you
the data you can use to test the
hypothesis
Check you know how to create
questionnaires avoiding bias
Make sure you know the advantages
and disadvantages
Understand how you can use a control
group.
Use an experiment to predict the
whole population
Make sure you know the advantages
and disadvantages
Make sure you know the advantages
and disadvantages
Make sure you know the advantages
and disadvantages
Presenting and analysing data
You need to be able to construct, use and interpret data in these formats:
Tallying / Frequency tables
Cumulative frequency tables
Cumulative frequency diagrams
Cumulative frequency step polygons
Two-way tables
Pictograms
Pie charts
Stem and leaf diagrams*
Choropleth Maps
Bar charts and vertical line charts
Misleading diagrams
Comparative Pie charts
Histograms (frequency density)
Frequency Polygons
Population Pyramids
Skew-ness
Averages and measures of spread
You need to be able to calculate, use and interpret data with these calculations:
Mode, Median, mean of discrete data in lists and in frequency tables
Mode, Median, mean of grouped data
Which average is best?
Transforming data
Weighted mean
Range
Quartiles and inter-quartile range
Percentiles and Deciles
Box and whisker plots
Outliers
Standard deviation
Standardised scores
Scatter diagrams and Correlation
You need to be able to construct and interpret a scatter diagram and interpret data:
Scatter diagrams
Association and Correlation
Causal relationships
Line of best fit and equation of
Interpolation and Extrapolation
Spearman’s rank
Time Series and index numbers
You need to be able to construct, use and interpret data in these formats:
Line graphs
Time series
Trends and trend lines including predictions
Seasonal variation and mean seasonal variation
Moving averages
Index numbers
Chain based Index number
Weighted based index number
Probability and Probability distributions
You need to understand all these laws of probability and know the probability distributions:
Trails, outcomes and events
Sample space
Theoretical probability
Experimental Probability
Mutually exclusive
Exhaustive events
Independent events
Risk insurance
Tree diagrams
Simulation
Venn diagrams
Addition law
Multiplication law
Conditional probability
Probability distributions
Uniform distributions
Binomial distribution
Normal distribution
Quality assurance
Understanding the language on the exam paper
When the questions says . . .
Calculate. . .
Work out or find out. . .
Write down. . .
It means . . .
Some working out is needed – so show it
A written mental calculation is needed.
Working out is not usually required. You should be
able to write down your answer using the
information given.
Estimate. . .
Work out an answer from a table or graph.
Estimating means you can not work out an exact
value.
Diagram NOT accurately
Often used for pie charts. Don’t measure angles
drawn. . .
from the diagram as they will be wrong. You may
need to calculate.
Give reasons or Explain why. . You need to write an explanation. Show any
working out.
.
Plot . . .
Add the points accurately to the graph
Draw . . .
Use the data to draw an accurate graph or chart
Use your graph . . .
Read the values from the graph and use them.
Predict . . .
Use something eg line of best fit to predict.
Compare . . .
Make any comparisons explicit. It is not enough
just to describe the items you are comparing.
Explain how they relate to each other.