The ADF software package uses a numerical integration scheme for virtually everything it may calculate. The number specified here is roughly the number of significant digits in your results. If you leave the field blank ADF will select a reasonabl default value.
Increasing the number makes the results more accurate, but will require substantially more computation time. Similarly, decreasing the number will result in less accurate results, but you will get the results faster.
For the tutorial, we will reduce the accuracy in order to speed things up:
Set the integration accuracy to 3.0.
The color of the field changes to yellow to warn you that you changed a field.
