Open the Fitting a Model: State Demographics Starter File and Save a Copy of the file that’s just for you.

The al-ak Model

Type fit-model​(​states-table, "state", "pct-college-or-higher", "median-income", al-ak​) in the Interactions Area, then find the points for AL and AK along the predictor line. Hint: You know their coordinates and they will help you know where to look!

1 What do you Notice?

2 What do you Wonder?

3 Find 𝑆 in the upper left corner. What is the 𝑆 value (the number after 𝑆)?

Other Models

In the definitions area, find the section titled Define some other models by modifying al-ak.

  • For now, all three definitions in this section are exactly the same as al-ak.

  • You will be changing them according to the directions below.

4 If you wanted the model to be less steep, what slope could you use?

  • Change the definition for less-steep to use the slope you wrote above.

    • Click "Run" to load your new definition. In the Interactions Area type: fit-model​(​states-table, "state", "pct-college-or-higher", "median-income", less-steep​)

    • What is the 𝑆 value of less-steep?

  • Identify a y-intercept that would make the model fit the data better:

    • Adjust the definition to use the new y-intercept and click "Run".

    • Hit the up arrow in the Interactions Area and click return/Enter to fit the model again.

    • What is the 𝑆 value of less-steep now?

5 Change the definition of negative so that it models the data with a slope that is negative.

  • Click "Run" and type the code to fit this model to the data.

  • What slope did you use? What is the 𝑆 value now?

6 Change the definition of horizontal so that it draws a horizontal model. Click "Run" and fit this model. What is the 𝑆 value?

7 Change the y-intercept so that the horizontal line passes through more of the points. Click "Run" and fit this model.

  • What y-intercept did you use? What is the 𝑆 value now?

8 What do you think 𝑆 tells us?

These materials were developed partly through support of the National Science Foundation, (awards 1042210, 1535276, 1648684, 1738598, 2031479, and 1501927). CCbadge Bootstrap by the Bootstrap Community is licensed under a Creative Commons 4.0 Unported License. This license does not grant permission to run training or professional development. Offering training or professional development with materials substantially derived from Bootstrap must be approved in writing by a Bootstrap Director. Permissions beyond the scope of this license, such as to run training, may be available by contacting contact@BootstrapWorld.org.