Methods of representing data. Students develop a sense that data can convey information and that organising data in different ways can help clarify
what the data have to tell us. They see a data set as a whole and so are able to use proportions and measures of centre to describe the data.
Interactive files for Statistics & Probability
I should be able to:
Foundation Level
Graphical
− select appropriate graphical or numerical methods to describe the sample (univariate data only)
− evaluate the effectiveness of different displays in representing the findings of a statistical investigation conducted by others
– use pie charts, bar charts, line plots, histograms (equal intervals), stem and leaf plots to display data
– use appropriate graphical displays to compare data sets
Numerical
− use a variety of summary statistics to describe the data
• central tendency: mean, median, mode
• variability: range
Ordinary Level
Graphical
− describe the sample (both univariate and bivariate data) by selecting appropriate graphical or numerical methods
− explore the distribution of data, including concepts of symmetry and skewness
− compare data sets using appropriate displays, including back-to-back stem and leaf plots
− determine the relationship between variables using scatterplots
− recognise that correlation is a value from -1 to +1 and that it measures the extent of the linear relationship between two variables
− match correlation coefficient values to appropriate scatter plots
− understand that correlation does not imply causality
Numerical
− recognise standard deviation and interquartile range as measures of variability
− use a calculator to calculate standard deviation
− find quartiles and the interquartile range
− use the interquartile range appropriately when analysing data
− recognise the existence of outliers
Higher Level
Graphical
− analyse plots of the data to explain differences in measures of centre and spread
− draw the line of best fit by eye
− make predictions based on the line of best fit
− calculate the correlation coefficient by calculator
Numerical
− recognise the effect of outliers
− use percentiles to assign relative standing
Presentations on Graphical Representations of data
T&L: The Correlation Coefficient
Revision: Overview of Statistics with Sample Questions & Answers