# What are absolute, relative and arbitrary scale?

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I have seen the wikipedia page but still a bit confused. Can anybody elaborate it in simple laymen terms with examples.
Thanks

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So an absolute scale is Kelvin for temperature, as zero is zero, there is no energy.

Celcius is a relative scale; it works the same as Kelvin but zero isn’t zero, the numbers are just easier to work daily as 0 and 100 are easy points to remember as cold and hot, rather than 273 as cold and 373 as hot

An arbitrary scale has no units it just shows something is greater than something else. I think an example is people rating something from 0 to 10. That value has no units it’s just a rating that can be used as a rough guide or for comparison

Absolute scale means something is measured from zero, and everyone has the same reference point. Temperature is measured day to day in Celsius (if you’re in a modern country) or Fahrenheit (if you don’t).

Temperatures measured in Kelvin start at zero and can’t go below. There is no condition under which anything will get under zero kelvin and we measure everything up from there.

It can go below zero in C or F-> they are not absolute.

+1C is the same as +1K but the starting point (zero) isn’t. Celsius is temp in K minus 273.15. -> this is a relative scale.

Now the 1 scale is based on freezing and boiling point of water divided by 100. That’s arbitrary. So the zero isn’t but the steps are.

Fahrenheit is arbitrary as it’s just conveniently spread across the freezing point of water and brine (zero F), the freezing point of pure water (32F) and human body temperature at 96 (later adjusted to 98). The split between 32 and 96 is 64 steps. That was decided because it easier to mark (making half dissections 6 times). See Fahrenheit wiki page.

So this scale wasn’t based on observations or facts, just basic human convenience. And that’s as arbitrary as it can get.

I would simplify all of the above:

Absolute scale: a scale of measurement with a reference point consistent across all users. Eg – directing someone to a map coordinate. The scale of distance is based on the global origin of 0 degrees – the prime meridian in Greenwich.

Relative scale: a scale with a flexible reference point.
To use location as an example again – directing someone to move 5 miles west, as opposed to giving them a map coordinate. The distance instruction is based on the location of the person, rather than a globally understood reference point.

Arbitrary scale: a scale with no consistent reference point used for comparison, rather than measurement.
The sports brand Puma have a score for social responsibility in their annual report. There is no reference for this score, so globally it’s meaningless. However, it can be used year on year to show Puma’s success or failure, provided the same criteria are used for measurement.