The following list describes how the Triple-S DSC maps Metadata Model (MDM) variable types to Triple-S variable types when writing Triple-S metadata and case data files.

The “Triple-S variable type” is as defined by the value of the type attribute in the Triple-S <variable> element.

For all Triple-S data types except character, system-missing values (that is, values that indicate that a question was not asked) are represented in a Triple-S case data file by spaces. Therefore, the Triple-S DSC outputs MDM Null values as spaces.

The Triple-S standard does not support user-missing values (that is, values that indicate that a question was asked, but not answered) except in single and multiple variables, where user-missing values are represented in a Triple-S case data file by zeroes. Therefore, the Triple-S DSC outputs MDM empty categorical values as zeroes.

For each category in an MDM single-response or multiple-response categorical variable, the Triple-S DSC adds a <value> element to the corresponding Triple-S variable. A Triple-S <range> element is not written.

The Triple-S DSC sets the value of the <value> element's code attribute to the value of the corresponding MDM category's Value custom property (see Custom properties used when writing to Triple-S files) if it exists. Otherwise, the Triple-S DSC sets the value of the code attribute to the index (or "sequential") value of the corresponding MDM category, that is, the Triple-S DSC sets the value of the code attribute to 1 for the first MDM category, to 2 for the second MDM category, and so on.

If the MDM document's SssVersion custom property (see Custom properties used when writing to Triple-S files) has a value of 2.0 and the MDM category's Factor property contains a value, the Triple-S DSC adds a score attribute to the corresponding Triple-S <value> element and sets the attribute's value to the value of the Factor property. Note that the score attribute is set only for Triple-S single variables and is not supported in version 1.2 of the Triple-S standard.

The exportation of nonnumeric custom values is only supported for single-response categorical variables.

For multiple-response categorical variables, the following restrictions apply:

For MDM variables that are mapped to Triple-S quantity, date, or time variables, the Triple-S DSC adds a <range> element to the corresponding Triple-S variable and might also add <value> elements. The way in which the Triple-S DSC sets the range, and how it decides whether to add <value> elements, depends on the following conditions:

If any of the above conditions are false, the Triple-S DSC sets the range of the corresponding Triple-S variable to the values of the MDM variable's EffectiveMinValue and EffectiveMaxValue properties and does not add any <value> elements to the Triple-S variable.

If all of the above conditions are true, the Triple-S DSC maps each MDM category to a Triple-S <value> element and sets the value of the element's code attribute to the value of the MDM category's Factor property. In addition, if the value of the Factor property appears in the value of the MDM variable's RangeExpression property as a single value, the Triple-S DSC ignores the single value in the range expression when setting the range of the corresponding Triple-S variable. For example, the following MDM Long variable has two categories that both have integer Factor values:

The Triple-S DSC will map this variable to a Triple-S quantity variable that has two <value> elements, and will set the values of the elements' code attributes to 500 and 999 respectively. Because the values of both Factor properties appear in the MDM variable's range expression as single values, the Triple-S DSC will ignore them and set the range of the Triple-S variable as 1 to 499. The resulting Triple-S <values> element for this variable would be as follows: