`NaN` stands for **N**ot **a** **N**umber and indicates that the data is missing.

Observations containing a value of `NaN` are automatically filtered from any analyses if the question they appear in is numeric. That is:

- NaN values have no impact upon analyses based only upon questions of the type: Pick One (Nominal in Displayr), Pick One – Multi (Nominal - Multi in Displayr), Pick Any (Binary - Multi in Displayr) and Pick Any – Grid (Binary - Grid in Displayr), except where numeric statistics, such as Average and Average are being displayed using
**Statistics – Right**or**Statistics – Below**. To automatically filter a value of these questions requires the selection of the category as**Missing Data**in the Value Attributes. - When used to construct JavaScript Variables, NaN values are treated as being missing values.
- NaN settings are ignored in Pick Any (Binary - Multi in Displayr), Pick Any - Compact (Binary - Multi (Compact) in Displayr), and Pick Any - Grid (Binary - Grid in Displayr) questions, and any variables in such questions only have values of 0 and 1.
- NaN values in variables used as weights are given a weight of 0.
- Observations with values of NaN on numeric variables used as filters are excluded from the filter.

## See also

Hiding and Removing Categories (Missing Values) in Q