Should you not wish to provide such information, just click the Next button, and the NPC algorithm will resolve the uncertainties. Note, however, that directionality for undirected links will be decided on a random basis, and that for those ambiguous regions with no information provided, all of the uncertain links will be removed, possibly resulting in a poor model.
For more information on the NPC algorithm and the notions of
undirected links and ambiguous regions, see the help page of the
previous page of the Learning Wizard.
The undirected links (not belonging to ambiguous regions) are drawn in
black. When selected, such a link gets highlighted and the two
directionality buttons get enabled:
Which of the above appearances of the pair of buttons are used depends on the relative positioning of the nodes of the selected link. Thus, it should be readily apparent which of the two buttons should be selected for achieving the desired directionality for the selected link. However, when positioning the mouse cursor on top of a button, a tool tip will appear after a short while, explaining precisely which direction is associated with the button in question.
Note that assigning directionality to a link may cause other links to
automatically be directed. If, for example, there are undirected links
between variables x and y, between y and z, and between x and z, then
enforcing the directionalities x --> y and y --> z implies x
--> z; otherwise, a directed cycle would occur.
Each ambiguous region is easily identified as consisting of links in the same color. (Note that there can be so many ambiguous regions that colors have to be reused, making it difficult from the coloring alone to distinguish them.) Also, when selecting a link of an ambiguous region, all links of the region will be highlighted; the one selected will be drawn bold and the other links will be drawn with double lines.
When a link of an ambiguous region has been selected, the
include/exclude link buttons get enabled:
When a decision has been made that a link should be present or absent, each of the other links of the ambiguous region will be affected in one of several ways:
The most recent (non-undo) action performed can be undone by clicking
the undo button:
Please note that an arbitrary number of operations performed can be undone by repeatedly clicking the undo button.
For each (small) set, C, of conditioning variables, a p-value for {A,B} is computed. This value expresses the probability that A and B are conditionally independent given C. The marginal p-value is the p-value corresponding to C={}.