Set Aggregate Thresholds

Hide aggregate values for small populations from users.

Note: Setting aggregate thresholds may result in a large number of metric values to be hidden. Before you enable this feature, contact Visier Technical Support for more information about user impact. There may be alternative ways you can hide certain details from users through data security.

An aggregate is a whole value made up of several units. For example, the aggregate compensation data for women in the New York office is made up of each individual woman and her base pay. Sometimes, there are very few members in a population, such as women in the New York office, which makes it possible for users to discover sensitive information from the data.

You can set an aggregate threshold to require a minimum number of members that must be in a population for aggregate values to be displayed. Aggregate thresholds make it harder for users to infer specific data values for members of small populations from aggregate values.

Example: Using aggregate values to infer individual data values

Rachel Chu is the only woman in the New York office. Users with this knowledge can apply filters to the data to uncover sensitive information about her. If users have aggregate access to compensation data, they are restricted from seeing the Base Pay value for specific employees. However, users can easily filter their analysis population to women in New York to see an aggregate value for Base Pay. From there they can conclude that the aggregate value displayed for the Base Pay metric is actually Rachel's Base Pay value.

Note: Even if aggregate thresholds are applied, users can still infer specific data values from aggregate values using math and filters. To ensure that users cannot access sensitive data, such as compensation, we recommend that you restrict their data access. You can do this by changing the access level for attributes from Aggregate to None. For more information, see Data Access Sets.

Aggregate threshold options

The following options are available when configuring the aggregate threshold:

  • No threshold: Aggregate values are displayed even if the population consists of only one member. No threshold is applied by default.
  • Set threshold for subjects: Aggregate values are hidden if the population falls below the aggregate threshold. You can set thresholds for individual or all subjects.
  • Set threshold for a subject property: Aggregate values are hidden if the population falls below the property's aggregate threshold.

Note: You can also set thresholds for event properties and multi-value properties that are associated with a subject.

Using the Employee subject as an example, you can set a threshold for:

  • Relocation Cost, an Employment Start event property.
  • Compensation Amount, Compensation Item, Converted Amount, Currency Code, and FTE Weighted, the simple properties that make up the Employee Compensation Items multi-value property.

What happens when thresholds are not met

Users should expect the following chart behavior when their analysis population does not meet the aggregate threshold:

  • Aggregate values are hidden and N/A values are displayed.
  • In a Trend visual, data points are removed which may result in gaps in the trend line.

How thresholds are applied

For metrics that are calculated using average headcount, the threshold is also applied to the population that contributed to the calculation.

Example:  

Turnover Rate is calculated as the Turnover Count divided by Average Headcount. The aggregate threshold for Employee has been set to 3. The Turnover Rate will be hidden if one of the following criteria is met:

  • The Turnover Count is less than 3.
  • Over the selected time period, the total number of unique employees is less than 3.

Set aggregate thresholds

  1. In a project, on the navigation bar, click Model > Settings > Aggregate Thresholds.
  2. Click Enable aggregate thresholds.
  3. Optional: Set the default aggregate threshold value which will automatically be applied to all and any new subjects.
  4. To set the aggregate threshold value for individual subjects, click Add.
  5. Select the subjects that require individual aggregate thresholds.
  6. For each subject, set a threshold.
  7. Optional: To override the subject's threshold at the property level, click Add Property and define a new threshold for the property.
    1. Define property overrides for related events in the Event Properties tab. Using the Employee subject as an example, you can define a threshold for Relocation Cost, an Employment Start event property.
    2. Define property overrides for related multi-value properties in the Related Objects tab. Using the Employee subject as an example, you can define thresholds for Compensation Amount, Compensation Item, Converted Amount, Currency Code, and FTE Weighted, the simple properties that make up the Employee Compensation Items multi-value property.

  8. When finished, publish your project to production. For instructions, see Publish Project Changes.

Example:  

Let's say you've set a default threshold of 5 for all subjects. This means that any population must have a minimum of 5 members to display values to users with aggregate data access. However, you want an increased threshold for your employee population, specifically at the gender and ethnicity level.

You can add two property overrides and set their thresholds individually. For example, a threshold of 30 for gender and 50 for ethnicity. This means that users with aggregate data access will not see values for populations that have fewer than 30 members for gender-based metrics or filters, nor will they see populations below 50 if they are looking at ethnicity-based metrics or filters.

Note:  

  • If a user has mixed access to a population that provides them with both detailed access to some individuals and aggregate access to others in that population, they cannot view groups that fall below the defined aggregate threshold.