Trend Analysis

About the narrative

Details covered in the analysis

If the value of the measure changes by more than a user-defined threshold over the selected time period, it is considered a trend. The user defines this threshold using the Trend change % option: see Configuration options for details.

Consecutive time periods with trends moving in the same direction are merged into one trend.

The narrative includes:

  • an overview section that describes up to three changes in the trend of a measure (rise to fall, fall to level, fall to rise, etc.). For example:

  • a section for each of the trends mentioned in the overview, drilling down by up to three dimensions, which includes:

    • a paragraph for the first level of drilldown (e.g. Country) that describes dimension instances (e.g. United States of America and Canada) based on the patterns they display, and whether they drove or offset the change in the overall value of the measure.

    • paragraphs covering the second and third levels of drilldown (e.g. Product and Segment) that describe dimension instances (e.g. Ointmo and Karateon, and Online and Departmental), reporting on the single most significant changes at those levels.

    For example:



    The order of drilldown is determined by the order of dimensions set in Step 1.

The narrative wording depends on the selected aggregation types, referring, for example, to total, average, minimum or maximum values. For the Percentage, Rating and Ratio entity types, total values are omitted from the narrative as it does not make sense to sum up non-additive measures.

The app attempts to describe as much detail as possible, but when there is too much to describe the narrative focuses on the later time periods in the series. If you want to analyze a specific time period, select specific dates as a subset of the full dataset.


Only the Important things narrative length is available for this app in Step 3.



Data requirements

All NLG Apps have the same data requirements relating to supported formats and field names. See the NLG Apps Data requirements topic for details.

In addition, each app has specific data requirements:

If your data selection and configuration do not meet the specific requirements for a particular app, the app is grayed out and disabled in the wizard. In this example, the Describe a Pie Chart app has been disabled:


Dimensions and measures

This app can analyze:

  • up to two time dimensions*, up to three non-time dimensions, and exactly one measure.

Minimum requirement: one time dimension* and one measure.


*Time dimension requirements for each analysis period:


For each time dimension, the Entity Type field must be set to DateTime in Step 1 of the wizard.

Aggregation and entity types

Not all combinations of aggregation and entity types are supported for measures. The Trend Analysis app can analyze the following combinations:



Aggregation types are set in Power BI.

Entity types and other data attributes are set in Step 1 of the Arria for Power BI wizard.


Arria Answers currently supports only the Sum aggregation type and the None and Currency entity types. When switching from an NLG Apps narrative to Arria Answers, make sure the measures chosen to generate the narrative meet these requirements. If they don't, Arria Answers will return incorrect responses.



Configuration options

The following options are available to configure:





Select the measure you want to analyze.

Default: highest priority measure from Step 1.



Select a time period for the analysis. The time period you select must appear as a field in your data.

Default: Month.


Trend Change %

Set the percentage value at which a change between two consecutive values of a measure is considered a new trend. The slider is adjusted in increments of 1%.

Default: 5%.