General approach to user-defined estimands
In addition to the general approach to user-defined estimands, which is described here under this topic, Amos provides a simplified approach to user-defined estimands that meets most needs. If the simplified approach isn't sufficient for you, you can use the more general approach described here.
You can specify your own estimands by writing a program in Visual Basic or in C#. This is a lot easier than it sounds, even for nonprogrammers. Typically, when you want to estimate something that Amos doesn’t calculate for you automatically, it is a very simple function of quantities that Amos does calculate. For example, your estimand is likely to be the difference between two values that Amos already calculates, or maybe a sum, a product or a ratio. In cases like that, the program that you need to write consists of a single line of code, along with some boilerplate code that Amos writes for you.
While a one-line program will suffice for many needs, you have available all the capability of a general-purpose language (Visual Basic or C#) when you need it. You can estimate any computable function of the model parameters.
This video (8 minutes and 30 seconds) shows how to estimate a single indirect effect, test it for significance and obtain a confidence interval for it.
This video (8 minutes and 53 seconds) shows how to estimate two indirect effects, their sum, and their difference.
This video (3 minutes and 18 seconds) shows how to find out if two standardized regression weights differ significantly.
This example shows how to create a user-defined estimand that has the side effect of writing a file that contains parameter estimates for each bootstrap sample.