Delays and Synchrony

by grouperlab

In our first post, we talked about how our research inspired us to start a GROUPER Blog to provide you with updates more frequently than our journal and conference publications.  We anticipate that the various projects going on in the world are moving faster than the year-long or half-year-long publication cycle permits us to get updates out to the designers.  In the previous post, Dr. Caldwell discussed the idea of people’s perception of waiting.  In this post, we will combine these two ideas with a discussion of waiting during information sharing.  We have talked about aligning the update frequencies of the design and our research output, and we have talked about what people feel when they wait.  Today, we will present our perspectives of a second timing concept, delay.

Delay, lag, latency, and lateness are all words that describe the fact that information does not arrive instantaneously to its intended receiver.  We can go into detail about why this is always true in another post, but to keep things brief we will limit today’s discussion to obvious cases of delay.  Consider cases where e-mails are sent across the Internet, voice mails are left for our family members, satellite news video feeds are transmitted up to orbit and back down on the other side of the world, and memos and documents are shared between team members.  All of these cases experience some large or small amount of delay between when the sender generates information and when the receiver gets that information.

When there is delay, people have to compensate so that they can still do their job well.  The degree to which they have to compensate depends on the medium of communication.  GROUPER classifies communication media two ways:  synchronous media and asynchronous media.  Synchronous media are those in which the sender and receiver wait for each other to send messages and receive messages.  Telephone conversations, chat-room messages, television and radio, and face-to-face communication are all synchronous.  The receiver can sometimes process the message as the sender is generating it, as in the case of a face-to-face message or telephone conversation.  Other times, the receiver must wait for the sender to compose and send the message, as in the chat-room message, but the receiver is still listening and waiting for the message.

In contrast, asynchronous media are those in which the senders do not wait for the receivers to get their message and respond.  This is because the senders can expect the delay in the communication to be longer than they are willing to sit there and wait.  E-mail, voice mail, postal mail, memos and documentation, and blogs are all asynchronous.  When dealing with asynchronous media, the sender can send a message and forget about it, moving on to other tasks.  The receiver can work on her tasks and forget about the sender until she decides to check for, or the medium notifies her of, a new message.

This is not going to turn into a physics / philosophy discussion about whether two events can actually be truly simultaneous.  Our focus is on whether the delay between events is meaningful compared to the time involved in the task requiring the information flow.  This depends on the task itself, and not just the total amount of delay.  If I’m listening to a stereo CD, or watching a video with audio track, a few tens of milliseconds makes a huge difference in my perceptual system’s experience of synchronous behavior.  However, if I send out documents before going on a week-long vacation “off the grid,” it doesn’t matter to me whether the responses take an hour or six days.  The GROUPER emphasis is on whether delay interrupts one’s cycles of task performance, with time spent waiting rather than doing.

On occasion, we experience a shift in the media, for example when sending an e-mail at work, we might receive a very quick reply.  We then reply quickly ourselves, and, for a short period, the e-mail medium becomes more like an instant-message (synchronous) medium.  However, GROUPER still classifies e-mail as asynchronous in general because at any moment the two communicators may leave the communication without the other being aware of it.  We’ve experienced both the unexpected reply to a late-night email, and the frustration and change in expectation when we realize that work time for us is either sleep or holiday time for someone else, and that is why they’re not available.

Neither synchronous media nor asynchronous media is always better than the other, but each have specific situations in which they are better and should be used.  For example, if the goal of the news channel is to deliver news to viewers faster than their competitors can, then they will want to forgo the option of editing the satellite news feeds from the reporter on-location and tolerate the delay in the live feed.  If the goal is to provide a company-wide notice of a new corporate policy, it may be best to not interrupt daily tasks, but to leave an e-mail for all employees for when they have a moment to really absorb it—and not require them to drop their tools and listen, for example.

The challenge that GROUPER has identified with regard to synchronous and asynchronous media is that, when communication has enough delay, it is not only disruptively long, but the receiver must nevertheless wait for the message to come through the medium before he can continue his work.  The receiver can also unknowingly continue to work in the environment with information that is either incorrect or incomplete.  For example, telemedicine can be both synchronous and asynchronous.  Telemedicine, or distance medicine, involves the use of technology to enable patients to communicate with their physicians and physicians to communicate with other healthcare professionals.  Telemedicine is synchronous when a patient communicates with his physician in real time via videoconferencing.  All of the information shared between the two parties is both timely and accurate and does not hinder the physician’s capacity to make informed decisions regarding the patient’s care—unless the patient is withholding certain information.  (See Vallette et al. (2011) for more information.)  Telemedicine can also be asynchronous, for example when two physicians, a primary care physician and a specialist, are communicating regarding a patient’s care and using email-like store-and-forward technology in order to share the patient’s medical history documents.  While using this technology allows the specialist to view the documents on her own time, the patient might come into the primary care physician’s office with an emergency, and the specialist might not see any change in the patient’s medical documents in time for the patient’s next visit.  Then she might make a diagnosis based on outdated information.  The specialist would never intend, of course, to make a misdiagnosis, but, unfortunately, in this case she may not know the whole story because of the nonroutine visit by the patient.  Without respect for the medical-document medium as an asynchronous medium, the specialist is more likely to forget that she may not always have the most up-to-date information.

Further reading:

Caldwell, B. S. (2008).  Knowledge sharing and expertise coordination of event response in organizations.  Applied Ergonomics 39, pp 427-438.

Vallette, M. A., Chafac, M. N., Benedict, A. J. & Caldwell, B. S. (2011). Reducing barriers to knowledge sharing among healthcare professionals and patients. Proceedings of the Industrial Engineering Research Conference. Reno, Nevada: Institute of Industrial Engineers, Inc.