Metric Display Standards. Best practices for presenting numbers

So what is the point of reading an article about a standard metric display if custom is better?

Well, first, I’ll make a pitch for the usefulness of understanding a few basic concepts that help you think through the solution to any metric design problem. As an analogy, consider how helpful basic math concepts are for dealing with all kinds of things. For example, I use the same grammar school arithmetic and touch of high school algebra to build all my various spreadsheets for managing money, estimating projects, or tracking physical exercise.

The second argument for being familiar with metric standards is to do with the trade offs that are always a part of product development. Is the time, expense and risk involved in developing a custom display over a standard one worth the expected return on that investment for your organization and your customers?

While you’re pondering that question, let’s run through metric display basics.

Metric Tile

The canonical metric display is a tile: a data visualization that must show the most current value of the metric and is infinitely more useful if it also displays a comparison of current and historical values.

Layout

The standard metric tile lays out current and historical values as separate zones stacked vertically.

Standard tile zones

Object Model

The object model for the metric tile has both required and optional elements.

Example showing required and optional (italic) elements of the tile object model

Label

The metric label must be an end user recognizable version of the metric name. Metrics tend to be stored in back end systems with cryptic names that need to be converted to a form that is meaningful to an end user before appearing in the metric tile. The label text should also function as the link to the detail view for the metric, discussed later under Interactions.

Value

The value is a number representing the most recent reading for the metric available. It is critical that the value is displayed immediately adjacent to the label, following a natural reading order, and without any elements other than white space separating them.

Unit

The unit is a name defined by standards, regulatory agencies, or common sense that identifies the kind of the thing the metric is measuring. The unit must be displayed because knowing the unit is critically important to assessing the meaning of the metric. For example, a hot tub water temperature reading of 100 has entirely different implications if the unit is Fahrenheit or Celsius! For common quantities with well known units, it is fine to use an abbreviation.

Timestamp

The timestamp establishes the recency and relevance of the value. It should report the time when the metric was actually measured, not when the metric was received by the application displaying the metric.

Trend Indicator (optional)

The trend indicator uses text and a directional symbol to communicate which way the metric is trending. The amount of change can be given as an absolute value, a percentage, or both. The directional convention is up or positive when the metric increases in value, down or negative when it decreases, and pointed right for no change.

The trend indicator has two tricky bits:

• Compared to What? To report a trend you need to compare a current value against a previous value. For example, stock trend indicators compare the current value against the value at yesterday’s market close. Unfortunately, most metrics don’t have a well understood previous value so you will need to choose a reasonable option such as 1 day ago or 1 week ago, or immediately previous, and accept that your viewer may need to consult documentation to know which you’ve chosen.
• Which Direction is Better? A second complexity arises if you want the trend indicator to communicate whether the change is good or bad. In this case your application will need to know, for each metric being displayed, whether to consider an increase good or a decrease good.

from Hacker News https://ift.tt/3lLHASP