Column Statistics Reference
This page describes the statistical information available for individual columns of data.
Statistics may vary depending on the column's data type. For example, the statistics retained for states may be different from the statistics for strings.
Most of these statistics are available in the Column Details panel, which can be opened from the left side of the Transformer page.
Below, you can review general statistics maintained for each data type, followed by breakdowns of statistics for each specific type of data.
Note
Before your job is run, profiling information such as column statistics are exact counts of the sample that is currently loaded. After the job is run, profiled results in the Job Results page might include estimates for some metrics and counts, depending on the scale of the dataset.
General Column Counts
For any selection of values in a column, the following counts are generally available.
Count Name  Description 

Valid Values  Count of values that are valid for the column's data type 
Unique Values  Count of unique values. Duplicate values are not counted. 
Outlier Values  Count of values that qualify as outliers. An outlier value is either:

Mismatched Values  Count of values that do not confirm to the column's data type. For example, an Integer column with a value of "MISSING" results in a mismatched value. 
Missing Values  Count of values that are not populated 
General Column Statistics
These statistics are available for most types of data through the Column Browser.
For string types (String, Phone Number, Social Security Number, Boolean, Email Address, Credit Card Number, Gender, IP Address, URL, HTTP Code, Date/Time), these stats measure string length.
For structured string types (Phone Number, Social Security Number, Boolean, Gender, IP Address, HTTP Code, Date/Time), any variation in these numbers indicates data problems.
Does not apply to: State
Statistic Name  Description 

Minimum  Lowest value in the column 
Lower Quartile  The median of the lower half of values (25th percentile) 
Median  The middle value of the selected set. For example, in a set of 21 values, the median value is the 11th value in ascending order.

Upper Quartile  The median of the upper half of values (75th percentile) 
Maximum  Highest value in the column 
Average  Average value in the column 
Standard Deviation  The computed standard deviation for the selected values. 