Communication Channels & Cell Phones

I noticed the other day that lots of states now ban talking on cell phones while driving, yet they don’t outlaw talking to a person sitting on the seat next to you. Why is that? I have a suspicion: talking to someone on a cell phone takes a lot more concentration. Many studies place accident rates for drunk drivers and cell-phone talkers evenly. The implication is that talking on your cell phone robs you of as much concentration as drinking!

But my experience with software development bears this out. I’ve worked on several geographically diverse projects, where the communication channel is reduced to phone calls in conference rooms. This is a terrible communication medium because you can’t see the other people, can’t see their facial expressions and body language, and don’t understand the subtleties of their vocal inflections. Humans are social animals (even developers who don’t interact well with other humanoids). We don’t realize how much we rely on those non-verbal communication channels until we notice how much concentration it takes to talk on a cell phone in a car.

Alistair Cockburn has a great diagram in his book Agile Software Development.

He has modeled communication effectiveness to temperature dispersal from a heating source. The further away from the source, the colder you are. This is a great metaphor because it takes into account the subtle communication channels upon which we depend but don’t realize are there until they’re not.

The importance of this for software development shouldn’t be ignored. If you engage in distributed development, insist on warmer communications, like video conferencing. Even Skype video, while crude sometimes, beats the phone-call-in-crowded-conference-room anti-pattern. On one of my projects, we had serious cross-ocean communication gaps because we’d never met in person. The results aren’t surprising: personality clashes, misunderstanding about technical problem resolution that cost us time, and general stand-offishness between the teams. Wisely, my project manager invoked the XP “Move people around” principle, and we shuffled developers from the US to India and vice-versa, for a couple of iterations each. This was on a fixed-bid project, so we incurred the cost for the travel ourselves. And it was the best thing that ever happened to the project. Once you’ve met people and spent time with them, it makes even conference call communication better, because you can pick up on subtle clues in people’s voices that indicate a facial expression you’ve seen for yourself. One of the developers on our US team was widely loathed by the developers in India (so much so that, when I went there, they had drawn an “X” over his face in the team photo we had on the wall!). But, when he went there himself, he became fast friends with many of the developers. Some personalities must be experienced in person before they are tolerable, especially to different cultures.

So, the next time you are driving and talking on your cell phone, do 2 things: keep an eye out for the police in your rear view mirror, and notice how much more mental energy it takes to talk on the phone rather than to a person sitting with you. This to me is the proof that Cockburn nailed it.