Try out the new table regressions in Desmos. This is so easy to use; I copied data from a spreadsheet and pasted it into a blank expression line. To create a regression, simply click the Add Regression icon to the left of your expression. I tried the Desmos table regression using a data set from this new Transum Activity, Odd Scatter Out, where students have to identify the odd one out from a set of 5 scatter diagrams. Link to Desmos page.
For more on Statistical functions with Desmos, see this article from the Desmos Help Centre.
Keep an eye on this Desmos playlist to see what’s new.
Further resources for correlation and regression:
This GeoGebra applet allows students to move points and watch the effect on the line of best.
This can be used in class by asking students to plot the points, draw their lines of best fit and then comparing with the computer. This worked really well on my phone, I simply sent myself an email with the link and was able to move points easily. This could also be used with younger classes when talking about lines of best fit.
We can also demonstrate correlation coefficients and lines of best fit with this PhET simulation on Least Squares Regression.
Choose from a range of examples or choose Custom to add your own points and guess then check the correlation coefficient. You can also draw your own line of best fit and compare it to the theoretical line of best fit. Note the option to include residuals for both your own attempt and the line of best fit.
We can check Regression Calculations using this Linear Regression calculator from Social Science Statistics.
On the subject of correlation coefficients, we can play a game to see how well we can guess the correlation coefficient! Guess the Correlation Coefficient.
From Cambridge PhD student, Omar Wagih ‘Guess the Correlation‘, a rather addictive game with a purpose – Omar Wagih is collecting the data on the guesses collected and using it to analyse how we perceive correlations in scatter plots. Select About to read the rules and further details.
We also need to look at ranked data and students must be able to calculate Spearman’s rank correlation coefficient from raw data or summary statistics. Again, Social Science Statistics, offers us a calculator which will be useful for checking work.
Calculation details provide a useful check on work.
Note Social Science Statistics also has a calculator for calculating the Pearson correlation coefficient.
