Cardinality in communication
The term cardinality is typically used in data modeling. It refers to the relationship between two objects and how they are connected. For example, a person should have a one-to-one relationship with a tax ID number (such as the U.S. Social Security number). But a person could have a one-to-many relationship with a phone number object (one person can have many phone numbers). The basic cardinality types are one-to-one, one-to-many, many-to-one, and many-to-many.
We can apply cardinality to verbal communication:
- One-to-one: A conversation between two people.
- One-to-many: A professor giving a lecture to a hall full of students.
- Many-to-one: A jury giving their verdict to a defendant.
- Many-to-many: A group of people at a party, all talking simultaneously at the top of their lungs.
For written and technical communication, cardinality is more complex.
One-to-one
In technical communication, the most common example of one-to-one cardinality is phone-based technical support. The end user talks directly to a company support representative. One-to-one communication is usually quite effective—if something doesn’t make sense at first, you can ask questions to clarify—but it is also expensive.
Figure 1: Phone-based technical support is one-to-one communication. Click on the play button to view animation.
One-to-many
Traditional publishing, including technical communication and user assistance, offer one-to-many communication. An author writes content that is consumed by many readers. One-to-many communication is much more cost-effective than one-to-one communication, but when writing for a large audience, authors necessarily create information that’s more generic than a person-to-person conversation.
Figure 2: Technical communication is one-to-many communication
There are several ways of defining Web 2.0, but for technical communicators, the critical issue is that Web 2.0 shifts communication from one-to-many cardinality into many-to-one and many-to-many. The publishing channel is no longer restricted to professional authors; instead, anyone can provide information to anyone else.
Many-to-one
Many-to-one communication means that multiple people are providing answers to a single person. For example, Person A posts a question on a mailing list and receives offlist responses from a dozen people.
Figure 3: Many-to-one communication involves multiple people providing information to a single person
Many-to-one communication is arguably the least efficient method of communication because of the overlap in effort to provide answers to a single person. However, for the person receiving the information, it’s often the fastest and the highest-quality communication channel. When several people provide answers, a consensus often emerges for the recipient.
Many-to-many
Many-to-many communication is at the center of the Web 2.0 concept. Everyone is requesting and receiving information, and roles shift fluidly from information provider to information recipient.
Figure 4: In many-to-many communication, the distinction between information producers and information consumers disappears.
Next page:
User assistance in a Web 2.0 world