The 2009 Summer Science Exhibition

On our stall we're talking a lot about the kinds of mistakes people make when using software, but the same errors can happen in real life too.

This morning I was locking my bike up outside the Royal Society when I spotted Peter, one of the main researchers from our stall. He was worried because no one who'd arrived yet knew the passwords for the computers in our exhibit. I told him I'd come straight away and log in as soon as I finished locking up. I attached the locks to my bike and ran in, and (still a bit sweaty and gross) proceeded to log into the three computers we've got on the stall.

It wasn't until I was changing out of my cycling clothes that I realised I didn't have my keys. I looked through all of my pockets, and then my bag. I started to get a bit tense when it came to me that I must have left them next to my bike. Given enough time a thief can get through any bike lock, but it definitely makes it a lot easier if the keys are in a nice pile right next to it. Once I was changed I didn't stop to lace up my shoes – I just ran straight out to the bike rack where, thankfully, my bike and my keys were still waiting. Phew.

I'd made a classic cognitive mistake, one that I've been spending the last two days telling people about at the exhibition. Locking up a bike comes with what's called a tidying-up task. You have to remember to take your keys away at the end. Tidying-up tasks are easy to forget, because you don't think of them as part of your main goal. To make matters worse, halfway through my task I'd been distracted by another goal to accomplish – logging in to our computers. The more things you have to think about at the same time, the more likely you are to make a mistake. Also, I was in a rush: I had to lock up my bike quickly so I could go solve a problem inside.

These are all perfect conditions to prompt a mistake. Once I got my bike locked up I just thought 'great, that's one job done' and went straight on to the next task, forgetting that I still had to pick my keys up off the ground. It's sort of like forgetting to turn off your headlights after you drive somewhere. Getting to your destination is the goal you're really thinking about, not remembering about your lights.

In the end everything was fine and my bike's still waiting for me outside the Royal Society. But these sorts of errors really matter in medical situations, where the consequences can be much more serious. Nurses get distracted all the time with new tasks to do. Let's say you're given a new task while in the middle of entering a dosage into an IV pump. When you come back to that main task, did you remember to press the 'confirm' button? If there isn't a noticeable cue to remind you to do it, you could easily forget and the patient would never get the drugs.

-- Jonathan

Image taken from Danny McL's Flickr photostream.