Blog posts in English

Testing is your sensory nerves

The human brain and nervous system is probably the most complex organ in nature. The brain depends on the nervous system to supply information which the brain can then use to make decisions.

Recently, my son Troels broke his arm. I have four boys, and my wife and I more or less expected one of them to break something one day. After all, boys are boys!

Unfortunately, Troels’ fracture turned out not to be as ‘standard’ as I had hoped: Both bones in the lower left arm snapped completely, and he lost senses in the little finger, indicating damage to the ulnar nerve. Troels’ case where a nerve is damaged and cause loss of senses has made me think about analogies to testing.

Xray of Troels' arm showing the steel inserts to stabilize the broken bones
Xray of Troels’ arm showing the steel inserts to stabilize the broken bones

Sensory nerves work like testers

Sensory nerves collect information, transform it lightly and transmit it. Just like testers test things, nerves sense things. Science has identified four ‘modalities’: Touch, the sense of location in space, pain, and sense of temperature. Testers have modalities too: We test for performance, usability, functionality etc.

When signals from a nerve stops, areas in the brain previously associated with processing sensory information from this particular nerve are reorganized to process sensory information from other nerves. Some claim that the brain has a lot of spare capacity, but this reorganization indicates that that is actually not the case: Neurons are not allowed to sit idle and are reused as soon as they become ‘available’.

Loosing senses in the hand is considered a severe handicap for many reasons, and one reason is that patients risk burning their hands because they are no longer warned by their senses to avoid heat.

In the same way, not testing a subsystem at all introduces a risk that serious problems will go unnoticed. This relates to the coverage problem in testing.

Diagram showing sensory nerves in the arm and hand (source: wikipedia)

Nerve cells regenerate very slowly, only about 1 mm a day, but even after the nerve itself has totally regenerated, the brain still needs to do some relearning. It will have to relearn its map of the hand. Troels is 8 so his brain is still very flexible and easily relearns, and his senses have almost completely returned to normal by now.

Nature is a fascinating source of new insights!

Troels at the hospital after having the fracture stabilized
Troels on the way home with plaster on and steel in the arm

Thanks to Jesper L Ottosen for reviewing and editing this article.

Blog posts in English

Communicating models: A psychological perspective

Simon Morley posted a very interesting post about Challenges with communicating models about two weeks ago. Mental models are what we unconscously use to understand a situation, and communicating models to others is an interesting challenge: “[…] models do not transmit themselves – they are not necessarily understood on their own – they need the necessary “synch’ing” to align both parties to achieve comprehension, communication and dialogue”, as Simon summed it up in a comment on the blog post.
Simons post and the very good discussion he and I had about it started me thinking on the psychological perspective and how important empathy is: The “synch’ing” relies on empathy.
I really liked Simons blog post because above all it highlights the subjectivity of mental models. Models are not something you can implement in an organisaton just by e.g. e-mailing them to all employees. If you want someone to ‘get’ your model, you need to actively communicate it. Which is not possible without empathy.
Empathy is something that we associate with friendship and love, but it plays part in all communication processes between human beings, including those we as testers engage with at work.
From time to time we come across people who seems to have a total lack of understanding of what we’re doing: Colleagues, managers, customers. Most of the time, people who don’t understand need only a good explanation of the situation and our point of view. But sometimes, an explanation isn’t enough: Some people just don’t seem to want to understand.
People under pressure or in stress can be like that, and we often associate this with aggressive behaviour, rudeness. Or maybe we just see the rudeness, and only later realise that maybe there was a problem with understanding.
Empathy seems to exclude this behaviour. Empathy relies on a cognitive ‘feature’ of our brain which attempts to copy thoughts and feelings of other people: It tries to decode what those who you interact with are thinking based on verbal as well as unconscious ques, e.g. body language. It’s quite obvious that having ‘a notion’ of what someone else thinks and feels can make communication much more successful – if you feel sympathy for the other persons feelings and thoughts.
This can work both ways: Loss of empathy in a situation can mean that you think everybody else thinks and feels the same as you, and it can cause quite a lot of confusion and frustration when you realise that other’s are’nt thinking the same as you.
It can happens to all of us: The brain is not a perfect and consistently operating machine, but rather a very adaptable and flexible organ. For example in situations of crisis, empathy is one of the first things to go. A person in a crisis shift from being a social creature to goal oriented and focused, typically on survival – at any cost.
There are people who don’t want to understand, e.g. due to politics. But there are some people who involuntarily just aren’t able to get to ”the other side” of the argument, for example because they’re having ”a bad day”.
(Some people with autism and ADHD can be characterised by having problems with empathy. This is a quite severe handicap for them, since not only do they have problems decoding what other people think og feel, they can also have problems seperating their own thoughts and feelings from what other people are thinking and feeling. The sad situation for empathy impaired people is that they often don’t have a choice: Even when everything is good is it extremely difficult for them to decode other peoples thoughts, feelings and intentions – and therefore extremely difficult for them to communicate and interact successfully. Noticing how successfully others interact often just makes them feel plain stupid. This can lead to severe depression.)

Blog posts in English

About Working Memory and Testing

Cognition is the word used to describe all the mental processes happening in our brains. Cognition relies on working memory, which is the memory we are using when we are solving problems or performing tasks.
Testers, for example, often rely on working memory to keep track of what we are doing and the observations we are making while we test.
Working memory is fallible. You will probably have experienced going to the fridge to check something, yet when you get there, you find that you have forgotten what you were lookoing for. It usually helps returning to the place where you first thought about it, but sometimes it’s gone completely. It can be quite frustrating!
Adults can usually hold up to five things in working memory at the same time over a time span of several minutes. Small children can only hold one. A friend of mine, who used to work in a nursery, told me about a small boy, who had just learnt to walk. He was good at it, but when someone called his name, he fell on his behind. Every time! It’s was quite cute, she said.
Some people have very poor working memory. My 13 year old son Aksel has Asperger Syndrome and a severe attention deficit disorder (ADD). His working memory is very poor. In school, he usually looses focus on what he is doing after less than a minute, unless something or someone is helping him. By using a lot of mental energy, he can keep focusing over about 10 minutes, but it exhausts him and he has to take a break afterwards.
Yet, he can build the most fantastic Lego creations, particularly on the computer, and be concentrated about it for several hours. He is also excellent in a go cart, where he can stay 100% focused for more than 30 minutes – and is still completely relaxed afterwards. I’m usually exhausted after just 10 minutes!
So what’s the difference?

The difference, I beleive, is that the Lego creation and the go cart isn’t loading his working memory: He does not have to remember what he is doing as it’s in the context. The Lego building application is even helping him keeping all the bricks in order: He doesn’t have to focus on looking for that missing brick, but can quickly browse for any brick without loosing focus on the thing he is building.
At school, Aksel and his teachers are working hard to find strategies for off loading his working memory.
Aksel and I share a lot of genes, and though my working memory is far better than his, it isn’t quite as good as I would like it to be. I’ve learnt myself a few strategies to overcome it, and it’s usually not any big problem, though.
But since testing, and in particular explorative testing, is very demanding on working memory, I sometimes feel working memory impaired and I have developed a few strategies for myself to overcome it.
Test scripting is one of those strategies: Scripts are working memory aids for me.
Scripting by mind maps, however, doesn’t work well for me. The linear script is probably easier to navigate for me. (I love mind maps for taking notes and for manuscripts when I’m speaking, though.)
Scrips are also excellent providers of a ”safe home” when I’m diverting off to explore something: I don’t have to worry about forgetting what I was doing. I usually don’t even have take notes, which is very good, since note taking is something I’m not very good at (though, with discipline, I have improved over the years).
Developing strategies to assist your working memory can a good thing for anyone, even if you have excellent working memory, but there’s no one solution that works for everyone: Some like scripts, some hate them.
Experiment and stick with things you find work for you: Handwritten notes, mind maps, scripts, drawings. And if you are in the mood, try to use your body: Most of our brain cells are allocated to interacting with our muscles and senses, and they can work for you too: Count with your fingers, move yourself (and your laptop) around, talk to yourself about what you’re doing, etc.
In case you want to learn more about the concept of working memory, I can recommend the following book. It’s about working memory in children (for education), but the concept is the same for everyone:
Working Memory and Learning: A Practical Guide for Teachers