# User-defined estimands

Amos comes with the built-in ability to estimate all of the
quantities that you normally want to estimate in a SEM analysis.
This includes model parameters like regression weights, and various
other quantities like standardized regression weights, covariances
and correlations among variables in the model, factor score weights,
and so on. (To choose from among Amos's built-in estimands, click
**View > Analysis Properties > Output** on the main
menu and put check marks next to the quantities that you want to
estimate.)

Sometimes you want to estimate a quantity that
Amos doesn't have the built-in ability to estimate. It may be a
simple matter of estimating the difference between two values that Amos already
estimates. Then again, you may want to estimate some more
complicated function of values that Amos already estimates.

Amos allows you to estimate any function of the model parameters, complete with bootstrap standard errors, confidence intervals and significance tests.

A simplified approach to user-defined estimands meets most needs and is easy to use.

A
completely general approach, which is somewhat harder to use, is
also provided.