In: Math
What are the most important things to consider when identifying a model to fit a set of data? Be sure to list as many characteristics as you can, but don't be afraid to share any thoughts, ideas, or uncertainties you may have about a particular model. If you're unsure about something, just ask some clarifying questions to help you get a better idea of what the model's key features are. Your post must have a minimum of 5 sentences.
1. Visually compare the graph of the data to the graph of the model. (Look for a pattern from the graph.)
2. Calculate a correlation coefficient,
r (for some models).
The correlation coefficient measures the strength and the direction
of a linear relationship between two variables. A value of |
r | near one may indicate a "good fit".
3. Calculate a coefficient of determination,
r2 (R2).
The coefficient of determination represents the percent of the data
that is the closest to the line of best fit.
| 4. Examine the residuals. Examine the scatter plot of the residuals, which depicts the measure of the signed distances between the actual data values and the outputs predicted by the model. A good linear model has residuals that are near zero and are randomly distributed. |
| 5. Think about your answer. Is your choice realistic? Don't use a model that will lead to predicted values that are totally unrealistic. |