IBM® SPSS® Amos™ 28

Suppose you want to estimate an individual's score on the latent variable WILLING in the following path diagram.

In other words, you want to estimate the posterior predictive distribution of that individual's score on WILLING, or possibly some summary of the distribution such as its mean.

Amos can estimate posterior predictive distributions only for observed variables, not for latent variables. So in order to estimate the posterior distribution of a WILLING score, it is necessary to change WILLING into an observed variable whose value happens to be missing all the time. There are two steps to doing this.

1.Change the path diagram so that WILLING is represented by a rectangle. First right-click the WILLING ellipse and select Toggle observed/unobserved from the menu that pops up. Then left-click the WILLING ellipse, which will change it into a rectangle.

2.Add a WILLING column to the data file, but don't enter any values into the WILLING column, so that it contains only missing values.

The path diagram and data file will end up looking something like this:

Let Amos add a variable to the dataset

You don't actually have to modify the data file. You can click Tools → Data Recode. Then in the Data Recode window click Create Variable. In the following figure, a new variable called V1 has been created as a result of clicking Create Variable.

You can change the new variable's name to a name of your choosing, such as WILLING:

If you wish, click the View Data button to see the column of missing values on the new WILLING variable: