The purpose of this new topic is to present a way that quantitative displays can be categorized into types based primarily on the purposes for which they are used. I'm planning to write an article or blog post on this topic, but wanted to get your feedback to help me think it through first.
We present quantitative information for various purposes, and each purpose requires that we design displays in particular ways to achieve particular outcomes. Excluding those that are used for mathematical purposes (e.g., a mathematical proof), we display quantitative information for four fairly distinct purposes.
Purpose #1: Lookup
Displays of this type, often called operational reports, are used to look up numbers that are needed to do one’s work. As such, they are usually designed as tables.
This is the type of display that business intelligence (BI) products have primarily provided in the form of production reports. Displays of this type do not directly support the primary purpose of BI, which is decision making. Instead, looking up facts that are needed to do one’s job is an operational task that rarely requires decisions, for the appropriate actions are prescribed.
Purpose #2: Narrative
Displays of this type are used to explain, inform, or persuade. A particular story needs to be told that is based in part on quantitative data. Displays of this type combine words, numbers, and images. They are sometimes presented live in meetings or recorded for later viewing, but are more often presented in documents. Infographics that involve numbers are a written form of quantitative narrative that combines text and graphics to tell a story.
Purpose #3: Monitoring
Displays of this type support one or both of the following purposes: 1) Maintaining awareness of what’s going on and how well things are doing, and 2) reporting situations that require action, either to correct a problem or take advantage of an opportunity. As such, displays of this type may prompt and support decisions.
Purpose #4: Analysis
Displays of this type support one or more of the following analytical purposes: 1) data exploration to find facts of potential interest, and 2) data sensemaking (a.k.a., data analysis or descriptive statistics) to determine what facts mean, and 3) data prediction (a.k.a., predictive analysis or predictive statistics) to anticipate what might happen in the future given specific conditions, based on an understanding of what has happened in the past. Data prediction requires an understanding of probability theory and the ability to build probability models. Understanding is the immediate goal of these activities. The ultimate goal is to improve decisions and the actions that follow. The lines that distinguish displays that are designed for these complementary analytical purposes are not rigid. A single display can serve multiple purposes, but any one of these purposes can often be best served by a display that was specifically designed to suit that particular purpose well.
Factors other than the purpose of the displays (i.e., what they are used to do) can also influence their design, including the display platform (e.g., a large screen on a desktop vs. a smaller mobile device such as a smartphone) and the skills of the user. The purpose of the display, however, is the primary factor that informs its design.