# Scale

Humans over time have acquired the skill to use a linear scale. Radio Labs aired a talk which explained about experiments done with children and some tribes who have not been exposed to linear numbers. The experiments suggest that we are conditioned to use numbers in non linear scales. It is easy to express differences in ratios than linear count between them. The experiments have also been replicated on animals and found that they also understand differences in ratios than the count in between.

We are accustomed to say that the difference between 1 & 2, 11 & 12, 1001 & 1002 are all same.  When we project these numbers side by side as countable items like trees or birds in a picture; every one will immediately spot the difference between 1 & 2, most will spot the difference between 11 & 12 given some time to count and people will struggle to find the difference between 1001 & 1002 unless the images are arranged in neat grid with enough time given to count. The results of an experiment with Amazonian tribe who had not much formal education is here. In short, it illustrates that people will be inclined to choose their scale to be logarithmic instead of linear one. Musical scales are non linear where the frequency doubles every octave. Like music even the colour frequencies of VIGBYOR is non linear.

We deal with numbers day to day and most of the working force have spent significant amount time in school playing around with numbers which were in linear scale. Deep inside us we still carry what we inherited from our ancestors and are well suited to deal with ratios. May be that is why our ancestors designed the musical scale to be non linear. “The Da vinci code” novel also talks about golden ratio which is observed every where in nature and that is non linear.

In software development I have observed this is true when it comes to estimations. Instead of mapping estimates to days of effort it is more easy to represent it in Fibonacci series (the ratio is 1.6 or golden ratio in fibonacci) or Log base 2. Trying to fit in a linear scale has created more misunderstandings between team members as each one had a different picture on where to place an estimate on a linear scale. I have observed dissonances in estimates from people even when using logarithmic or fibonacci, that dissonance will increase manifold if we use a linear scale. If we try to deal with numbers in ratios in day to day life then may be we can get lots of advantage by using our hard wiring inside.

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