Manually specifying error estimates

Manually specify error estimates at each level

Proceed to design modification and costing

Proceed to design modification and costing

Manually specify error estimates at each level

If it is the case that estimates of the standard deviation (SD) are available then they can be entered into the form as shown here.

This is the simplest of the three methods to provide PowerNest with enough information to calculate the error of a particular design in the next section. It is also, however, the least reliable in that the errors are not deduced directly from the data. Situations in which it is appropriate to use this method are limited; it is usually the case that the errors are estimated from data-sets obtained from the same laboratory, using similar subjects/samples, and studying the same biological effect.

Once satisfied with the standard deviation estimates click the banner for section 3 and proceed to the design modification section.