Tuesday, 11 January 2011

The Feedback Loop

One of the critical elements of following the session based test management (http://www.satisfice.com/sbtm/) approach is the use of quick feedback. To achieve this it is suggested that a debrief should be done at the end of each session/day. Jon Bach (http://www.satisfice.com/articles/sbtm.pdf) suggest the use of PROOF

Past. What happened during the session?
Results. What was achieved during the session?
Obstacles. What got in the way of good testing?
Outlook. What still needs to be done?
Feelings. How does the tester feel about all this?

This approach is excellent for communicating what has happened during the testing session(s), however I keep hearing that people are not doing the debrief . There are many reasons why these are not being done, lack of time/resource or see no benefit are a few of the reasons given. This blog post is why it is important to carry out these debriefs and ensure they are done sooner rather than later.

I am looking at this from a psychology viewpoint to highlight the way our minds work and to keep reminding readers that software testing is a human sapient process and not an automated ticking of boxes process.

There are various studies that have indicated that the longer you take to act upon information the less you are able to recall that same information at a later date. During Eurostar 2010 Graham Freebur stated that unless you act upon information you had digested at the conference then within 72 hours that information would start to be lost and fade. The crucial part of this is that as humans we are fallible and lots of different psychological biases start to play with our minds so unless we can talk and pass on the information we have as soon as possible the more likely that the data we have will become clouded.

It is important that we debrief to someone to ensure that any error in our interpretation of the system under test can be corrected. The reasoning behind this is when we are testing a complex system we make assumptions as we test and the system may appear to confirm our assumptions and as such fuel what could be incorrect interpretations of the system. A computer system will never be able to inform you that your assumptions are wrong or right it could indicate a bias one way or another. The only way to repair errors in interpretations is to interact with a human being. This is the reasoning why debrief is very important so that any assumptions can be challenged and if necessary corrected.

As humans we are very good at being adaptive and changing our viewpoint and opinion when presented with new information but to do this effectively it needs to be a conversational setting, we are very bad at dealing with delayed feedback and the longer it is left the more likely we will keep our initial bias and interpretations.

The point of this rather short blog post is to explain why debrief after a testing session is important and that it needs to be done as soon as possible. Delays and excuses only cause more assumptions and incorrect information to appear to be the correct answer.

Make the time to debrief, plan for it and use it, it is crucial element of testing.


  1. Hi John,

    Excellent & valid point. Consider weekend testing without the one hour chat at the end & just testing, nothing else! It wouldn't have worked as well; people wouldn't have learned as much from it.

    Consider an internal testing challenge without feedback, discussion on good & bad aspects. Again you'd lose out on so much knowledge gained from collaborative discussion.

    Myself I've yet to experiment with SBTM. It's something our team is keen to adopt. My main driving force for wanting me to try it is simply the debriefs. From these alone I feel our teams skills could improve greatly, if done correctly.

    Nice post & thanks for sharing.



  2. Yes, good points.

    At SWET1 Henrik Andersson talked about his experience with 'PROOF', and how some teams stopped doing debriefs so he tried 'PROOF LA' (L-Learning & A-Adaption), with some success.

    Some snippets are reported here.

  3. Thank you for the comments Darren and Simon

    I had spoken previously to Michael Bolton about PROOF and he had said it had been updated to something else - I just could not remember at the time. Thanks for the prompt and reminder Simon.