Excluding fields from the target table

By default, all the fields in your target table will be made available for analysis. However, when you first open up a table you are given the option to exclude fields by changing the usage status of each field.

Excluding fields will speed up processing and you should therefore exclude any fields when you are sure that they will have no use or influence on your analysis project, for example:

·Fields that are unique index identifiers. In general, a field that holds a 'customer account code' or a 'product code' would be of no predictive value.

·Telephone numbers or area codes. Fields like this need more thought as in some instances they might be needed, but rarely in their original 'as is' form. For example, you may want to use these to identify geographic groups. However, it is more likely that only the main exchange number or first part of an area code would be suitable and the field would therefore need pre-processing to achieve this. There are also possibilities such as 'telephone given' Yes/No would be a useful field, whereas the actual number would not - such as on a credit loan application form.

Note that excluding fields is a simple process. However, take some care when using similar table data sources as secondary data sets. You may need to ensure that you exclude the same fields.