User suggestion: pin My Line to Mean Point

[oliver-phet]

It would be beneficial If the “My line” could be pinned to the mean point and if the sum of the residuals could be Displayed as well.

If you pinned the (My line) to this mean point, you could rotate the line through that point.
The residuals will always have a sum of 0 when the line is pinned to the mean point.

I tell my students that the LSRL will be such that the sum of the residuals is 0.
This happens when a regression line goes through the mean point.
But there are an infinite number of lines that can go through the mean point.
So there are an infinite number of lines that would create a 0 sum of the residuals.
The LSRL has the additional property that the Sum of the squared residuals will be minimized.

So on the applet we can “find” the LSRL by first pinning our guessed line to the mean point of the data
and then trying to minimize the sum of the squared residuals there after.

[oliver-phet]

Assigning to @amanda-phet to review and comment.

[amanda-phet]

There are a lot of features like this that would be great to include (although it would require a different screen), we just don't have the resources right now to devote to designing and developing a new screen for this sim.

I'll leave the issue open to consider in the future if we get a grant that could be applied toward adding this feature.

[oliver-phet]

Email to user sent.

[amanda-phet]

Just had another user email with the same suggestions (perhaps the same user?)

Good day,

I am a high school Statistics teacher, and I love using your regression applet to help introduce Least Square Regression to my students.

I do have two suggestions that I think would make the applet even more powerful. Since the LSRL must go through the mean point and the residuals sum to zero only when a fitted line goes through the mean point, I think it would be helpful if there were

1. An option to show the sum of the residuals

2. An option to pin the “My Line” to the mean point. From here, the slope could be changed, but the line would remain on the mean point. The residual sum would show as 0, and the students could minimize the squared residual sum.

Thanks for considering,

Rolf Arnesen

Mathematics Teacher

Huntingtown High School

Huntingtown, MD