This is an experiment. I’m trying to figure out my understanding of what the word ‘Heuristics’ means to me and whether it’s helpful to me and my craft: Testing.

Therefore, I’ll rehash an old story of how I found a bug and annotate the heuristics used in Bold and see what I can analyse from that afterwards.

Any guidance, ideas, intuitions, sources are very much appreciated.

Finding a Memory Leak

It was past noon. I’d been testing an application that wasn’t too complex for quite a long time. I knew it’s ins and outs and I felt myself getting bored.
I remember going through the customer files rather methodically one by one, click,… click,… click , without a clear aim. You could say I was randomly exploring.

Until something didn’t feel right. Call it surprise, intuition, something was wrong.
I noticed a pattern of loading times slowing down almost unnoticeable. I can’t put to words what triggered it for me. Was it an Observer-expectancy effect? Was it my negative mindset that sharpened my senses? I haven’t got a clue, but I felt I had to focus, zoom in.

I chose a tactic that was less boring than meticulously clicking my way up. Selenium IDE isn’t the best of tools, but it fit my purpose perfectly. I recorded my click and copied it a thousand times. I monitored the behaviour with developer tools, pressed ‘play’ and went for a coffee. After a while, I could identify that it went terribly slow because I could see the latency increase. Eventually I saw it ramping up until it crashed. Pairing with a developer we could conclude that there was a serious memory leak.

Implicit and Explicit heuristics?

A heuristic is “A fallible approach to solve a problem”

The teachings of RST and BBST and possibly how ‘heuristics’ were meant in the science books would identify all the bold phrases as some variation of a heuristic. I’m sure many other heuristics played in my mind that I don’t have words for yet.

However, notice how the first part of my story is almost completely based on hunches and feelings. Something directed me to find this bug and it wasn’t intentional.

In the second part, I took matters into my own hand. I had a goal, I chose a tactic and was able to measure my results. Other tactics, could have been clicking the button myself for the umpteenth time and miss out on a coffee. I might have asked a developer to look into it straight away and maybe had time left for two or three coffees.

I can’t know for sure whether I chose the correct heuristic or tactic for that situation and I’m sure as hell “# of cups of coffee drunk” isn’t the correct way to measure that success.

We can’t go back in time and compare results of heuristics used vs. the ones not used. Though I’m pretty happy with the results of the one I set up.

The Question Remains

Are the ‘Implicit heuristics’, (i.e. feelings, patterns, biases, hunches) which can’t really be controlled, measured,… useful to call heuristics? They fail, yes. They help you notice things, yes. But do they solve problems?

Are ‘Explicit heuristics’, (i.e. repetition to find boundaries, monitoring for abnormalities, pairing to increase understanding) worth a dime without their implicit counterparts?


It’s not up to me to answer these questions. Yet I find it intriguing to ponder over the matter.