% fortune -ae paul murphy

Gulf of execution

As some readers have commented I can be a little out of touch sometimes - and so it's not terribly surprising that a buzzie I thought I saw for the first time in this Sun blog by Yuan Lin turns out to have been around for nearly twenty years.

Gulf of Execution.

Gulf of Execution is a term used to describe the the difference between the steps one actually needs to take to achieve a goal and the steps that one perceives.

After learning this term, the example that quickly jumps into my mind is setting up those wifi-enabled devices, like Wii, PSP, NDS, Wireless gateway, etc. In my experience, the one with the narrowest gap is iPhone. The worst one is, well, some operating system.

What's particularly embarrassing about this, however, is that I once read the book the term comes from: Donald Norman's User Centered System Design: New Perspectives on Human-computer Interaction.

I don't know why the term hasn't stuck with me - it's immensely useful in response to all kinds of delusions around the data sphere. People who don't believe they futz with their PCs, for example, suffer from this - while those who believe the SAP project planning presentation made just before implementation kickoff could presumably be sent to explore the cauldrons of execution at Kilauea.

The biggest, deepest, and deadliest, gulf is, of course, the development delusion where "Yes, I can" is usually punished by months of misery as all the details and people whose impact you missed in the project plan turn milestones into excuses and your definition of success slowly morphs into escaping alive.

Development is not, however , either the most tragic-comic or most linguistically apt example for the phrase "gulf of execution" - that honor surely goes to the Wintel security industry. To cite some random examples illustrating the successes purchased by that industry's Arabian Gulf sized $10 billion in annual revenues: the U.S. Army had to publically announce a move to restrict USB drive use; a triptych of British hospitals had shutter their client-server networks for a few days, a couple of guys named Beck and Tews found a way around the temporal Key Integrity Protocol used to keep wi-fi communications "secure", and Starbucks had to publically ask 97,000 employees to "monitor their financial accounts for suspicious activity and to take appropriate steps to protect against potential identity theft", after another laptop went missing.

Of course, Norman, as I'm now reminded, was also guilty of the phrase "gulf of evaluation" - a phrase that has fallen frequent victim to people who write definitions like these:

The Gulf of Execution represents the difficulty the user has in translating a psychological goal into a physical action.

The Gulf of Evaluation represents the user's difficulty in evaluating whether the response of the computer system meets the desired goal.

because that may well have been closer to what he meant than our use of the terms in IT where:

  1. the "gulf of evaluation" describes the extent to which your bosses believe your planning document (PERT chart, cost forecast, etc) realistic; and,

  2. the "gulf of execution" models the extent to which you do.

Either way, however - and remember that "their" definition is ours shifted from the implementor's view to that of the user - the real bottom line question here is what the value and obvious applicability of these terms tells us about ourselves?


Paul Murphy wrote and published The Unix Guide to Defenestration. Murphy is a 25-year veteran of the I.T. consulting industry, specializing in Unix and Unix-related management issues.