Check out Overfit v underfit by noreply@blogger.com. Here is an excerpt:
You’ve got data!
That’s a good start. Now, working back to cause for these effects, what model fits the data? If you get the model right, you can forecast (gasp! estimate) what comes next.
You can make two errors, both of which could be costly, but one more than the other:
Underfit the data….
The full article is available here.
