10: Summary

For a scatterplot For a barchart
Choose x and y Same!
Label x, y, and give a title Same! (except x usually has no units)
Decide minimum and maximum values for x and y Only for y — and include the error bars
Decide distance for ticks Only for y
Make a legend Same
Add data, using dots Use rectangles, not dots

Choosing between SD and SE

Measures how far members of the population deviate from the average Measures how far your estimate of the mean (from a sample) probably deviates from the population mean
Quantifies the population Quantifies your experiment
Does NOT depend on sample size DOES depend on sample size (a lot!)
Use to characterize the population Use to test your results

Learning outcomes

Now that you have worked through this module, you should be able to:

  • Determine whether a bar chart or scatter plot is the best type of graph for the data you have.
  • Construct a bar chart.
  • Add error bars to a bar chart using either the standard deviation or standard error.
  • Determine, which of the standard deviation or the standard error is a more appropriate measure to describe the variability in a particular circumstance.


If you want a printer-friendly version of this module, you can find it here in a Microsoft Word document. This printer-friendly version should be used only to review, as it does not contain any of the interactive material, and only a skeletal version of problems solved in the module.