Inattentional blindness and test scripts

“We asked 24 radiologists to perform a familiar lung-nodule detection task. A gorilla, 48 times the size of the average nodule, was inserted in the last case that was presented. Eighty-three percent of the radiologists did not see the gorilla. Eye tracking revealed that the majority of those who missed the gorilla looked directly at its location.”(1)

We think we pay attention to things but it’s not like that. We’re aware of only a small part of what we see at any moment. So we might even look at something and not be able to see it – it seems eyes actually look at something but without actually seeing it.

Initially, when I thought about test scripts in conjunction with the concept of inattentional blindness, I imagined it was a way to disprove test scripts entirely. I say this because of the following logical reasons:

– If a test script is being followed with great precision, then for sure other things are overlooked. Therefore, this means the script is not a very useful technique;

– But if the tester says that it will also check other things that are not included in the test script, in a way this behaviour invalidates the test script.

In other words, these two approaches practically invalidate the idea of a test script.

I admit I was biased with test scripts because I saw it (and I still see it) applied in a very very wrong way.

James Bach surprised me by saying that, actually, test scripts are an advanced test technique that should not be done by novices(2).

An advanced tester is aware of his/her limitations and makes sure that the testing is not affected in a bad way when using test scripts.

The reason why a junior tester should not receive test scripts is because, the likely scenario is that the test scripts will not be run as they should be(2). A junior/novice tester should be guided/accompanied by a senior tester.

This is praxis(3)….


(1) Trafton Drew, Melissa L.-H. Võ, and Jeremy M. Wolfe, Psicholigy Science September 2013;24(9):1848-1853, “The Invisible Gorilla Strikes Again:   Sustained Inattentional Blindness   in Expert Observers”: http://search.bwh.harvard.edu/new/pubs/DrewVoWolfe13.pdf

(2) James Bach, Rapid Software Testing class discussion [2017]

(3) Dave Snowden,  “Of practical wisdom”:   http://cognitive-edge.com/blog/of-practical-wisdom/

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