Computed Questions

A computed question is not asked; instead, its value or response is computed from a formula which uses other questions, constants and system variables. Its value is intended for later use. Its possible applications are:

• An argument in a later skip condition.

• Insertion in the long label of a later question (using < >).

• Data to be extracted to some external data file.

• Selection of a choice in the computed question itself. This choice may then contribute to quota fulfillment, choice elimination, or recalls.

Note: A question used in a formula must be numeric i.e. it must bear a $R or $E mask, and it must not have choice categories.

You create a computed question exactly as you do a regular question, however you specify an IF Condition for a complex skip whose destination must be an asterisk (*), which means: skip to next question in any case. You then enter a computation formula rather than a skip condition, the syntax rules of which are the same.

Example 1

Suppose that we have the following two questions, Q23A and Q23B, asking for the quantity and frequency of consumption of some XYZ product:

Suppose now that we would like to express the combined response to these two questions in terms of annual consumption. We create question Q23C and perform the calculation:

Example 2

A computed question which does not have response choices can only have a value. However, if it does have numeric choice codes, the system will look for a match between its computed value and one of its own choice codes. If a choice code matches the computed value, it will be selected.

Suppose that we have a question Q1 with two choices: Yes, No. and that we would later like to recall the text 'Accepted' or 'Refused' respectively. We create question Q2 and perform the selection.

Later on in another question we could recall Q2 for insertion in its long label. Example:'Since you have <Q2> our offer...'