Attention, attention…

The concept of inattentional blindness has been, if you’ll excuse the unintended pun, brought to the testing world’s attention lately by Cem Kaner and James Bach. Sajjadul Hakim has written recently on an exploratory testing experience in which he attributed failure to observe a bug to inattentional blindness.

While this may have been the cause, it is worth pointing out that our attention is a fragile thing. Inattentional blindness is but one of the ways that our brains can let us down while testing. Here are a few more:

Attentional blinking

If something grabs our attention, then something else happens almost simultaneously, or just after, we may miss it.

Inhibition of return

If something happens somewhere where we were just looking, we are less likely to see it.

Negative priming

Our brain applies filters to suppress things that are not relevant to the task at hand. These filters can arise through conscious effort or can happen if we perform a task long enough. An example of this is ‘banner blindness’, where things appearing in the spots where website advertising usually appears are highly likely to be ignored.

I became acutely aware of this effect last year. Steve Irwin had just died, and the news came to our team via a phone call to a teammate. I immediately jumped on CNN’s website, looking for confirmation. “There’s no news of it here,” I confidently claimed to the rest of the team. I looked back at the screen, and scrolling across the top of the page was a ticker, proclaiming Irwin’s death as ‘Breaking News’. It’s position at the top of the page, where advertisements usually appear, had caused me to skip straight over it.

Our brain is able to put filters in place to help optimise our performance of common tasks. These effects can last for more than a month after we have stopped performing the task that caused the filters to be put in place, just in case we need to do it again.

Our brain’s processing power is limited. In addition to the above problems, sometimes there’s just too much for it do deal with. It has developed tricks to help us survive lapses of attention, but these are also things that can catch us out as testers. The act of operating the product in order to test it is something which focuses our attention. By doing so, we blind ourselves to some problems.

I play video games with a kind of unfocused stare, and I suspect this actually helped me detect different kinds of problems when testing games, while probably making me blind to others. I find I can’t usually test applications with that protracted stare. I can however observe the application this way by putting the application under computer control, or by observing a playback of a recorded session. Video recorders and Watir scripts are great for this, and give you the chance to find different problems. James Bach also frequently recommends Spector for recording testing sessions.

Strategies

There are plenty of strategies for reducing attentional failures. Mix these up over the lifetime of the project for best effect. Some of them I’ve described already, but others I leave for you to Google –

– Rotate people through projects and tasks to avoid negative priming.
– Negative priming effects are reported to be reduced by alcohol consumption. Have a drink at lunchtime. Tell your boss science says it’s OK!
– Pair up…Maybe even with non-testers or people who have nothing to do with the project.
– Use recording tools and go back and review your testing sessions.
– Automate operation of the product, sit back and observe. I’ve used this technique, and Jonathan Kohl has success stories to tell as well.
– Blink testing. This is a defocusing strategy popularized by Michael Bolton and James Bach. Find different problems in test results, fast, by taking the detail out of them and scrolling through them quickly or zooming out.

If you would like to find out more, check out the book Mind Hacks: Tips & Tricks for Using Your Brain (Hacks). It’s a great primer on your brain, how it works, and how it can let you down. The ‘Developing Intelligence’ blog is also another great source of information and ideas.