Heuristics, Bias and Critical Thinking in Testing

Heuristics, Bias and Critical Thinking in TestingGetting to know the most powerful test tool in the world; your brain

Quotes There is nothing so useless as doing efficiently that which should not be done at all. Peter DruckerOur comforting conviction that the world makes sense rests on a secure foundation: our almost unlimited ability to ignore our ignorance. Daniel Kahneman

AgendaWhat is testing?Why do we test?What is the value of testing?Why do people pay for testing?Rocket scienceWhat are we on about today?What are heuristics?Why is bias important?What is critical thinkingThe Brain RulesWhat are they?Why are they important to testing?Thinking Fast and SlowSystems 1 and 2HeuristicsBiasCritical Thinking SkillsHow can I use them?Breaking System 1Putting it all together

Introductions

Introduce yourself

Me

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What are we on about today?

Lets start thinking now!

Rocket Science

Some quick definitionsAll from Wikipedia; for better or worse

HeuristicA heuristic, is any approach to problem solving, learning, or discovery that employs a practical methodology not guaranteed to be optimal or perfect, but sufficient for the immediate goals. Where finding an optimal solution is impossible or impractical, heuristic methods can be used to speed up the process of finding a satisfactory solution. Heuristics can be mental shortcuts that ease the cognitive load of making a decision. Examples of this method include using a rule of thumb, an educated guess, an intuitive judgment, stereotyping, profiling, or common sense.

Cognitive BiasA cognitive bias is a pattern of deviation in judgment, whereby inferences about other people and situations may be drawn in an illogical fashion. Individuals create their own "subjective social reality" from their perception of the input. An individual's construction of social reality, not the objective input, may dictate their behaviour in the social world. Thus, cognitive biases may sometimes lead to perceptual distortion, inaccurate judgment, illogical interpretation, or what is broadly called irrationality.

Critical ThinkingCritical thinking is clear, reasoned thinking involving critique. Its details vary amongst those who define it. According to Beyer (1995), critical thinking means making clear, reasoned judgments. During the process of critical thinking, ideas should be reasoned and well thought out/judged. The National Council for Excellence in Critical Thinking defines critical thinking as the intellectually disciplined process of actively and skilfully conceptualizing, applying, analysing, synthesizing, and/or evaluating information gathered from, or generated by, observation, experience, reflection, reasoning, or communication, as a guide to belief and action.'

Cognitive BiasCritical ThinkingHeuristic

The Brain Rules

Exercise and SurvivalExercise boosts brain power

The human brain evolved too

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Attention and Short Term MemoryWe dont pay attention to boring things

Repeat to remember

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Long Term Memory and StressRemember to repeat

Stressed brains dont learn the same way

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Vision and Exploration Vision trumps all other senses

We are powerful and natural explorers.

The desire to explore never leaves us

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Hang on! What about Wiring, Sleep, Gender and Sensory Integration?

Your brain is unique

Sleep well think well

Mens and womens brains really are different

Stimulate multiple senses to learn well

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Heuristics and Cognitive Bias

An individual has been described by a neighbour as follows:

Steve is very shy and withdrawn, invariably helpful but with little interest in people or the world of reality. A meek and tidy soul, he has a need for order and structure, and a passion for detail.

Is Steve more likely to be a librarian or a farmer? Steve is selected at random from a representative sample:

The two systems of your brainhttps://www.youtube.com/watch?v=KyM3d4gQGhM

Your mind doesnt stop on what you dont know, it just makes the best of what you do know. https://www.youtube.com/watch?v=uqXVAo7dVRU

The problem however really arises when we use system 1 instead of system 2 when system 2 would be the appropriate system to use, and this leads us to all kinds of biases and fallacies that are not optimal.

EasyHardYour brain is lazy and likes to do what comes easily

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Its easy for your brain to use Heuristics

Not thisThis

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An example heuristic and bias - PrimingPriming is an implicit memory effect in which exposure to one stimulus influences the response to another stimulus.

https://en.wikipedia.org/wiki/Priming_%28psychology%29

Where Heuristics lead to faulty thinking we are BiasedBananas Vomit

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Cognitive EaseRelated ExperienceClear DisplayPrimed IdeaGood MoodCognitive EaseFeels GoodFeels FamiliarFeels TrueFeels Effortless

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Mood effects the working of system 1

Critical ThinkingMaking the best of Systems 1 and 2 and using the Brain Rules to your advantage

How to be a better tester

Test the Rocket Science

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What tests would you run?

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What is a Critical Thinker?

Based on what we know how credible is this?

What if we have to decide and we dont have all the facts

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Critical Thinking Tools

Core Critical Thinking Skills

Becoming a better Test ProfessionalWhat does all this mean?

What do you think?

Some ideasCombining vision and exploration for powerful test representationDe-stress yourself and make it interesting and find your work more stimulating

Some more ideas

Both/And not Either/OrA good environment, regular hours and good sleep

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Even more ideasWhere would you like to work, how can you make where you do work more like where you would like to work?Combining analytic and exploratory approaches

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(Yet) more ideasWork with peoples natural circadian rhythmsStructure your teams to have variety of attitudes/approaches/strengthsLimit hierarchy to the minimum, horizontal equality facilitates problem solving, debate and innovation.

Bibliography and ReferencesThinking Fast and Slow Daniel Kahnemanhttps://www.youtube.com/watch?v=KyM3d4gQGhM The Brain Rules John Medinahttp://www.brainrules.net/ Index Cards by Jessica Hagyhttp://thisisindexed.com/ David McCandless Information is Beautiful http://www.informationisbeautiful.net/visualizations/rhetological-fallacies/ Check out StrengthsFinder and Belbin Team Roleshttp://gallupstrengthscenter.comhttp://www.belbin.com/

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Supplementary Information

Another view of Critical Thinking

https://tamimunzani.files.wordpress.com/2010/05/thinking_skills_lr1.jpg