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Data collection and analysis - intermediate

This lesson comprises three (3) master classes focusing on:

  • Types of data
  • Representing data with dot plots, column graphs, line graphs, sector graphs and divided bar graphs
  • Frequency distribution tables, frequency histograms and frequency polygons
  • Stem and leaf plots
  • Box plots
  • Mean, median, mode and range
  • Standard deviation
  • Interquartile range
  • Surveying and sampling

Content:

MA4-DAT-C-01


Classify data as either numerical (discrete or continuous) or categorical (nominal or ordinal) variables

  • Define a variable in the context of statistics as any characteristic, number or quantity that can be measured or counted
  • Classify and describe variables as numerical or categorical
  • Describe a numerical variable as either discrete or continuous
  • Describe a categorical variable as nominal or ordinal
  • Distinguish between and compare numerical (discrete or continuous) and categorical (nominal or ordinal) variables

Display data using graphical representations relevant to the purpose of the data

  • Represent single datasets using graphs, including frequency histograms and polygons, dot plots, stem-and-leaf plots, divided bar graphs, column graphs, line graphs, sector graphs and pictograms, with or without digital tools
  • Include sources, titles, labels and scales when displaying data in a graph
  • Select the type of graph best suited to represent various single datasets and justify the choice of graph
  • Represent a dataset using a statistical infographic and justify the choice of graphical representation used

Interpret data in graphical representations

  • Identify and interpret data displayed on graphs
  • Identify features of graphical representations to draw conclusions
  • Interpret patterns in graphical representations to make predictions
  • Explain why a given graphical representation can lead to a misinterpretation of data

 

MA4-DAT-C-02


Calculate and compare the mean, median, mode and range for simple datasets

  • Calculate the mean (\( \overline{x} \))of a set of data using digital tools
  • Calculate and describe the mean, median, mode and range of a dataset
  • Classify the mean, median and/or mode as measure(s) of centre to represent the average or typical value of a dataset
  • Describe and interpret data displays using mean, median and range
  • Identify and describe datasets as having no modes (uniform), one mode (unimodal), 2 modes (bimodal) or multiple modes (multimodal)
  • Identify the range as a measure of spread to describe variation in a dataset
  • Compare simple datasets using the mean, median, mode and range

Interpret the effect individual data points have on measures of centre and range

  • Informally identify clusters, gaps and outliers in datasets and give reasons for their occurrence in the context of the data
  • Identify and explain the impact of adding or removing data values that are clustered at one end of a dataset on the measures of centre
  • Identify and explain the impact of outliers on the measures of centre and range
  • Determine and justify the most appropriate measure of centre to summarise the data in its context

Analyse datasets presented in various ways and draw conclusions

  • Identify and describe the shape and distribution of a dataset using the terms symmetrical, negatively skewed and positively skewed
  • Associate the shape and distribution of a dataset with the relative size of the mean, median and mode using the terms symmetry and skew
  • Define a census as a study of every unit, everyone or everything in a population
  • Define a sample as a subset of units in a population selected to represent all units in a population of interest
  • Draw conclusions and make informed decisions about data gathered using data-collection techniques, including census and sampling, which is then presented in tables, graphs and charts

 

MA5-DAT-C-01


Examine standard deviation as a measure of spread

  • Identify standard deviation as a measure of spread
  • Calculate the standard deviation of a small dataset using digital tools
  • Compare small datasets using standard deviation

Determine quartiles and interquartile range

  • Determine the 5-number summary for sets of numerical data
  • Determine the 5-number summary from graphical representations
  • Determine the interquartile range (IQR) for datasets
  • Compare and explain the relative merits of range and IQR as measures of spread

Represent datasets using box plots and use them to compare datasets

  • Represent numerical datasets using a box plot to display the median, upper and lower quartiles, and maximum and minimum values
  • Compare 2 or more numerical datasets using parallel box plots drawn on the same scale
  • Compare and contrast the centres, spreads and shapes of 2 or more numerical datasets, using box plots and numerical statistics, including the 5-number summary
  • Determine quartiles from datasets displayed in histograms and dot plots, and represent these as a box plot
  • Identify and describe skewness or symmetry of datasets displayed in histograms, dot plots and box plots
  • Interpret box plots to draw conclusions and make inferences about the dataset