Path Construction Tool
Click the Path tool button on either tab of the Structural Equation Modeling Startup Panel or the Model tab of the Monte Carlo Analysis dialog box to display the Path Construction Tool dialog box. The Path Construction Tool is used to construct path model files in the PATH1 language, with virtually no typing. Because you type latent variable names only once, never have to type manifest variable names, and never have to enter paths manually, there is virtually no chance of a syntax error. Even extremely complicated models can be entered in a few minutes with this tool. For an outline of how to use this tool including examples for some options, see How to Use the Path Construction Tool.
- Variables
- Use the options under Variables to specify variables. When the Path Construction Tool is first activated, the Manifest Variables list is presented in the To variables column. The variable names listed are those already in the *.sta file. If you want to add latent variable names, you will have to edit the latent variable names list (See Edit latent, below).
- From, To
- Select which variables to display (Manifest or Latent) using the appropriate list box. To add variables to the Paths box, select one variable in the From box, one variable in the To box, specify a path type, and click the Add >> button.
- Path Type
- Use the options under Path Type to specify path commands. Besides the basic arrow and wire path types, there are options for three additional multiple path commands. These commands automate operations that are (a) highly repetitive, and (b) common to most path diagrams.
X-->Y. Click the X-->Y option button to create a basic arrow path type.
- X--Y
- Click the X--Y option button to create a basic wire path type.
- Residual
- Select the Residual option button to create residual (or "disturbance") variables automatically for all currently highlighted variables in the To column.
- Correl
- Click the Correl option button to insert paths for the correlation coefficients among a set of latent or manifest variables. STATISTICA does this automatically for all variables highlighted in the To column.
- Covar
- Click the Covar. option button to create paths for the variances and covariances of all variables highlighted in the To variables column. It operates in virtually the same way as the Correl. option.
- Add >>
- Click the Add >> button to create paths according to the currently created options. The new paths will appear immediately in the Paths box. If you don't like them, simply delete them with the Cut button (see below).
- Edit latent
- Click the Edit latent button to display the dialog box for editing latent variables. Within this dialog box, you can add, delete, or change latent variable names.
- Paths
- Review existing paths in the Paths box. STATISTICA offers editing capabilities, to change and/or reorganize the existing paths. These options are described below.
- Cut
- Click the Cut button to delete the highlighted paths and place them on the Clipboard.
- Paste
- Click the Paste button to paste the current contents of the Clipboard into the Paths box after the current cursor position.
- Copy
- Click the Cut button to place a copy of the currently highlighted material on the Clipboard.
- Parameters
- Use the options under Parameters to control if, and how, free parameter numbers are inserted in the paths you create.
- Include
- Select the Include check box to include a free parameter in the path. The number will be the value entered in the Par # field (see below).
- Increment
- Select the Increment check box to increase the free parameter value in the Par. # box (see below) by 1 after each parameter number is added to a path.
- Par. #.
- Specify the parameter number to be added to the next path (if the Include check box is selected) in the Par. # box. When the Path Construction Tool is first activated, this value is set equal to one more than the highest parameter number currently in the active model.
- Renumber
- Click the Renumber button to renumber all highlighted paths starting at the value in the Par. # field. The renumbering preserves all order relationships, and same-difference relationships in the parameters of the highlighted paths. It is important to remember that the action of the Renumber command is affected by the current settings of the Include and Increment check boxes. What this means is that, if you Renumber paths with the Include check box cleared, all parameter numbers will be removed from the paths.
The Renumber command is a powerful and convenient one for making your programs easier to read. It is best, when finishing a program, to renumber the paths, starting at 1. In this way, it is easy to verify the number of free parameters in a model.
The Renumber command can be especially useful when you are creating a multiple groups model with similar models in each group. You can simply Copy the model for the first group, then use the Renumber command to renumber the parameters.
- Start Value
- Use the options under Start Value to control whether a start value is added to a path, and what value is added.
- Include
- Select the Include check box to add a start value to each path.
- Value
- Specify the start value to use in the Value field.
- Residual variables
- Use the options under Residual variables to determine the base name and number to use for all residual variable names created during the current residual variables operation. These options are only available when Resid. is selected under Path Type.
- Base name
- In the Base name box, enter a base name to use for all residual variable names created during the current residual variables operation.
- Base number
- As residual variables are created, STATISTICA adds the number entered in the Base number box to the Base name, then increments it appropriately. So, if the Base name is DELTA, and the Base number is 5, the first residual variable created will have the name DELTA5, the second DELTA6, etc.
- Group
- Click the Group button to add the command Group # (where # is the integer in the adjacent field) to the Paths file after the current line.
- Endgroup
- Click the Endgroup button to add an Endgroup command to the Paths file.
- Comment
- Click the Comment button to display the Path Tool - Enter comment dialog box to enter a comment.
- Parameters
- Click the Parameters button to display the Analysis Parameters dialog box.