Describe a Line Chart

About the narrative

Details covered in the analysis

The length of the narrative and the level of detail the narrative contains depend on which Tell me how to say it narrative option is selected.

The line chart narrative includes:

  • descriptive statistics stating total values and outliers across time.

  • time-based variance analysis, i.e. comparison between time periods.

  • trend detection, i.e. trend over the smallest unit of the selected time dimension, provided there are at least 5 data points available in the underlying data.

  • correlation analysis over multiple measures, if multiple measures are selected.

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.


Day-on-day, week-on-week, month-on-month, quarter-on-quarter, or year-on-year analysis will be performed depending on the dates covered in your dataset.



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 four time dimensions, up to two non-time dimensions, and multiple measures.

Minimum requirement: one time dimension and one measure.


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 Describe a Line Chart 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.



Configuration options

The following options are available to configure:




Tell me how to say it

Summary: produces a narrative of filtered facts in a more concise way than the Important things option.

Important things: produces a narrative of filtered facts based on Arria's ranking algorithm.

Tell me everything: produces a narrative that includes every fact extracted from your data by Arria's algorithms.

Default: Important things.