RUM Terminology

The following table lists terms that are commonly used with RUM reports:

RUM Terminology
Term Definition
90th Percentile An aggregation method generally used for large sets of data, where 90% of the data points are smaller and 10% are larger. Removing the top 10% is seen to eliminate data points that are far outside the norm.

In terms of user experience, 90% of all users experience a time below this number.

Aggregation method A measure of statistical distribution.
Bar Chart A graph that uses vertical (or horizontal) bars to compare data categories against a value or metric.
Dimension For RUM, dimensions describe properties of the request, such as the browser used, or which features were used.

Within a dimension are various values. For example, a continent dimension may include the following five values: Asia (AS), Australia (Oceania–OC), Europe (EU), North America (NA), and South America (SA).

Histogram Histograms provide a visual interpretation of numerical data. They indicate the number of data points that lie within a range of values. The ranges are configurable between 0.1, 0,5, 1, and 2 seconds.
Median An aggregation method for the “middle” value in a list of numbers. The median value is one where 50% of the values are larger, and 50% are smaller.
Metric A metric is a standard for measuring or evaluating something that is expressed in a numerical value.

For available Navigation Timing metrics, see Available Metrics for RUM Reports.

Navigation Timing A specification from the World Wide Web Consortium (W3C) used to define a JavaScript-based performance timing interface for use with Web applications. For more information,

see W3C Navigation Timing.

Pie Chart A pie chart is a graphic in which each slice area is proportional to the quantity it represents.