Introduction to Stocks and Flows in Online Communication (part 1 of 3)

The following article is the first in a three-part series that will serve as an introduction to two terms that have had a profound effect on me and my work. The terms are "stock" and "flow" and this article is an introduction to these terms.


In a meeting recently, Jerry Michalski drew a diagram of communication tools and media in the context of "stocks" and "flows". His diagram first introduced me to how these terms can be used to describe online communication.

After the meeting, I contacted him and we talked more about the terms, what they mean, where they originated, etc. He related that they likely originated from the economics world. Upon doing a little research, I found that the terms are used frequently in systems dynamics and economics.

Update: I have recently learned that the terms were first used by Jay Forrester at MIT in the 1950's. Thanks to Bill Harris for the info.

Jerry also related that he wasn't aware that anyone else had used the terms in the context of communications or media. With his encouragement and help, I've written this article to help introduce "stocks and flows" to the world in the context of online communication. I hope that you'll see, like me, that these terms provide a powerful new lens through which we can view and discuss online communication tools and resources.

What are stock and flow? How do they relate to online communication?

In this context, stock and flow are states of electronic communications. Communication is either in a state of flow or it is stocked, and sometimes in transit from one to the other. For example, the kind of communication that comes from an instant message is flow- its value is linked to the timeliness and context of the message. The information is used as it is created. People engage in a flow, like a conversation.

A message board archive is a good example of a stock- it is stored until needed or requested. Its value is linked to accessibility and organization as opposed to timeliness. People access a stock, they don't engage in it. Stocks are generally static and presented when requested, like search results.

General definitions:

Flow: Information flows to the user; timely, emergent and engaging
Stock: Information exists at a specific location, static, archived and organized for reference.

With the emergence of weblogs, email lists, wikis, message boards, instant messaging, etc., Internet users are surrounded with ways to communicate and share information. By understanding stocks and flows, we have a new way to analyze and codify communication resources. Stocks and flows give us a new tool for describing the applicability and value of online communication tools and methods.

An Example:

A year ago I was an online community manager. The community started as an email list and eventually moved to a message board. Before the transition to the message board, we asked members about the most important elements of the community. They overwhelmingly agreed that the email notifications were very important, but the volume had become unmanageable on occasion. Further, they saw value in a message board system that archived each message (sent in email) in a searchable and organized fashion.

Looking back, I can see this situation as a classic example of stocks and flows. The community was originally founded on pure flow – the messages flowed into email inboxes as they were posted. As the volume of messages grew, the need for stocks became apparent - the members couldn't keep up with the flow and needed a back-up in the form of message archives. The emails provided the flow, the message board provided the stock.

In this case, the ultimate value came from using stocks and flows in concert. By continuing with automatic email updates (flow), we were able to keep members engaged while at the same time giving them confidence that the messages in email were also being archived on the web site for future reference (stock).

Next Section:

As we'll see in the next section of this series, similar examples emerge when we look at other online communication resources. Specifically, we'll look at how weblogs, wikis and RSS fit into the picture of stocks and flows. This section will be posted on April 5th, please stay tuned.

Next: Weblogs Wikis and RSS