Training

For market basket, cluster, and similar types of analysis, it is often advantageous to collapse specific set variable categories into more general ones. For example, a supermarket may have hundreds or thousands of unique items. Rather than examine the associations between, for example, the purchase of chicken and each of a long list of vegetables, it may be more useful to reclassify all meat items into one category and all vegetable items into another. Once you collapse the variables, you can use the set to flag node to create multiple flag variables from each of the new set values, which the association or cluster analysis nodes can then use as input fields.

The reclassify node (new in Clementine 8.0) makes it easy to regroup fields such as the one described above. You can either replace the original values for a field, or create a new field and retain the original, which may be a safer approach.

To reclassify a field:

• Place a reclassify node from the field operations palette downstream from the source node
• Click the field list button for Reclassify field and select the field you want to reclassify
• Type the name of the field you wish to create in the New field name box
• Click the Get button for a list of the values from the original field
• Type the new category values into the New value box next to each Original value or select one from the drop-down list. The drop-down list contains the new values entered thus far.

Figure 1 is an example of how the reclassify node should look when you are finished (click on the image below to enlarge):