It is common to set either a prefix, or a suffix, or both, for a numeric response question.  These can ber specified by adding the relevant characters to the prefix and suffix fields in the question editor.  A string of up to 5 characters is permitted for the prefix; up to 8 characters are allowed in a suffix.  The character(s) used in the prefix or suffix will then be displayed (to the left and to the right respectively, of the value entry field) on the participant device. 

Common prefixes are currency symbols such as Can$; common suffixes include units such as km, kN, or other explanatory text strings such as "units" or "lengths."

Example 1:

A numeric question requires a correct answer of "25" (or its numeric equivalent, plus or minus whatever tolerance may have been specified).  The prefix "$" is specified, as is a suffix of ".00".  The relevant section from the question editor form is displayed below on the left; the effect on the participant's response screen is shown on the right:

Editor:	Participant:

As an aside:  The use of the suffix ".00" in this case is not really necessary since Xorro-Q is testing for the arithmetic equivalence of the participoant's respoinse to the set string.  In this case, the intent is to correctly assess a response of "25"however a participant who enters "25.0" or "25.000" will also be marked as correct.  However, if a participant enters $25" the response will not be accepted, as a numeric string is required.  The user will not be penalised.

Example 2:

A question anticipates a response in a specified unit of MPa. This would normally be made clear in the question text (eg "Express you answer in MPa to zero decimal places), however the use of the suffix in this case acts as an added reminder for the participant as it displays the required units next to the entry field.  The relevant section from the question editor form is displayed below on the left; the effect on the participant's response screen is shown on the right:

Editor:	Participant:

Categories: Xorro-Q, Facilitators.