If you’ve come to this page, you’re probably really eager to read my list of the best scales of measure. I urge you to be patient for a few more paragraphs and instead indulge me for a bit while I explain how I’ve worked out my criteria for inclusion.

Methodology

Stanley Stevens published a paper called On the Theory of Scales of Measurement. which provides a wonderful typology of different scales. He largely broke scales down into Nominal, which are generally classifications, like biological taxa, film genre or nationality; Ordinal, which are sorted scales that don’t express a meaningful mathematical relationship, like the colours of the rainbow; and then Interval and Ratio, which are both numerical scales which either don’t have or do have a meaningful zero value respectively, e.g. Degrees Celsius vs Degrees Kelvin.

I’m mainly interested in Ordinal scales here. I feel they give the right amount of precision (over Nominal Scales, which are basically taxonomies, although I love those too) while still being sufficiently divorced from plain mathematical truth so that we still get a bit of insight into whoever drew them up.

There are hundreds of such scales. Inclusion on this list is generally because the scales are sort of neat as a way of thinking about something from daily life[1], and also allow us to peak into the minds of their namesakes.

Other people judge scales on all sorts of things, such as precision and inter-rater reliability. That’s not my bag.

A note on scores

There are some measures named “Scales” which are actually “Scores”. Scores are a set of judging criteria, each to be evaluated and associated with a numerical value and then added up to give the final number. I don’t really tend to count those as true scales, as they’re not really linear (as there are numerous different combinations of the values of each criteria), and usually aren’t as exciting as Scales. I’ve included one sneaky Score in here (the Epworth Scale), because it’s close to my heart.

The Best Scales of Measure


  1. Richter Scale – Earthquake magnitude

    This was the first scale I was aware of as a kid. Mainly because I loved geology. As far as I’m concerned it’s the original scale. Extra points for being logarithmic, which basically means that shit gets shaky, fast.

  2. Beaufort Scale – Wind force

    This is another one I loved as a kid.

    All the descriptions in it read like Japanese poetry: “Wind felt on exposed skin. Leaves rustle. Wind vanes begin to move” and “Small wavelets. Crests of glassy appearance, not breaking”.

  3. Glasgow Scale – Actually 2 scales: Coma and Outcome

    The guys at Glasgow University have two scales named after them. Unfortunately, they’re both pretty grim, being about how deep comas are, and how unlikely a patient is to return to normal life after brain injuries.

    With the Coma scale, there’s an interesting problem, whereby even though there are a couple of better options (Simplified motor scale, FOUR score), there’s no consensus as to which of the alternatives is the best, so the old one stays. That’s like us sticking with Nokias because nobody can agree whether iPhones are better than Androids or not.

  4. Fujita Scale – Tornado Intensity

    Unlike with Beaufort, this scale doesn’t mess around with small fry weather vane stuff. Designed in 1971, its assessment criteria are oddly soothing and remind me of the Wizard of Oz whirlwind in Kansas: “boxcars overturned”, “mobile homes pushed off foundations”, “sign boards damaged”. In 2007 the US government replaced it with the Enhanced Fujita, which sounds like something from Dragon Ball Z and includes far more modern references, like concern over shopping malls and steel-reinforced concrete structures, both of which would have definitely killed a few munchkins as well as the wicked witch if Dorothy had been shopping at Walmart.

  5. Waffle House Index – Storm Impact

    So if the Fujita Scale has got you confused with all its talk of Relative Frequency and Average Damage Path Width, and you’re just getting through your 9th helping of pancakes and maple, trying to work out if it’s safe to stop eating and go outside, this is the scale for you. It’s an “informal metric” used by Federal Emergency Management Agency to determine the impact of a storm and the likely scale of assistance required for disaster recovery.

    There’s only three ratings: Green, which means the restaurant is serving a full menu, Yellow, which means there’s a limited menu, possibly indicating “there may be no power or only power from a generator or food supplies may be low”, and Red, which means that Waffle House is no longer serving, so basically the world might as well be over.

  6. Scoville Scale – Spiciness[2] of chili peppers

    There’s several great aspects to this scale. Firstly, it works by a panel of experts being given solutions of the pepper in increasing dilutions of water until they can no longer detect any spiciness. That means that A. there are people who are “expert spiciness detectors” and B. this is basically also a test for when the solution becomes a valid homeopathic[3] cure for spiciness.

    Secondly, there’s the eye-watering difference up the scale. Jalapeño peppers, which sorta hurt my tongue and make me hiccup like nobody’s business, are rated at 3,500 Scovilles. Then there’s the world’s hottest chilies, the “Carolina Reaper”, which are rated at 2,200,000. That means that if you had to drink a whole pint of blended Jalapeños, or a pint of water with 10 drops of Carolina Reaper mixed in, you should go for the Jalapeños mess. At least then you look more macho than the guy whose eyes are streaming as he drinks his innocent but deadly glass of transparent death.

    Fun fact; a restaurant near me in Hoxton Square offers a Hot Wing Challenge, with Naga Viper Chilies (a paltry 1.3 million Scovilles). One Trip Advisor review reads “The Hot wings will ruin your life”. I was there with a friend who isn’t great with numerical scales but is keen to prove his cajones. After quitting one wing in, he drank 3 pints of milk and a Yazoo and still had to go home and cry.

    Pay heed to this scale.

  7. Likert - Self-reporting survey responses

    OK, so this is a bit of a meta-scale. I feel this is probably the scale-writer’s scale of choice.

    It’s basically the scale that goes from “Strongly Agree” to “Strongly Disagree”. The wikipedia page goes full nerd about it, suggesting “obtaining interval level estimates on a continuum by applying the polytomous Rasch model” and that Likert’s name “is among the most mispronounced in [the] field”. I “strongly agree”.

  8. Bristol Stool Scale – Consistency of Human Faeces

    This scale is funny because it’s about poo. It’s also known as the Meyers scale, which is presumably because multiple people really wanted to spend the rest of eternity associated with different types of turds.

    I really just recommend you check out the wikipedia page for this one. You can find out what the “ideal stools” are and it has a handy digram that is available as a mug. It’s basically a Buzzfeed article waiting to happen.

  9. Mohs Scale – Mineral Hardness

    This scale is kinda cool because firstly, the scale itself is just made up of minerals (a rating of relative hardness from Talc to Diamond) and secondly, it’s not just like “is this harder than quartz”, you actually use the minerals listed to test. So you go around with a test kit containing all the minerals on the list (available here – but “Diamond is not included” 😒) and try scratching the thing your trying to test until it stops scratching back. If only Forbes used this technique on its rich list and took Bill Gates around different Saudi kings until they found one he couldn’t buy.

  10. Kinsey Scale - Sexual response/preference

    So given that this scale could be fairly summed up as “how gay are you?”, it seems like it could have been conceived to aid scientifically-minded school bullies. Actually, it and the report it was introduced in were a bit of a revolution for the understanding and acceptance of everyone on the sexual spectrum when it was first published in 1948. Given the time period, it’s no surprise that some of the assessment criteria sound a little stilted: “more than incidentally homosexual”.

    Obviously, human sexuality isn’t well expressed by the the number 0-6 and the letter X, so this has been superseded by other measures with even cooler names, like Klein and Storms. (So calm down, Tumblr)

  11. Epworth Sleepiness Scale – Sleepiness

    OK, so hands up, this is definitely actually a Score rather than a Scale, but as a narcoleptic, this is something personal to me. Besides, there’s something soothing to thinking of pleasant life situations like “Lying down to rest in the afternoon when circumstances permit” and considering whether I might have a “moderate chance of dozing” or a “high chance of dozing”.

  12. Schmidt sting pain index - Insect Sting Pain

    So it would be criminal not to include this scale here, solely because of the dedication of entomologist Justin O. Schmidt in compiling it. Schmidt has been stung by “every goddamn awful thing in existence”, and compiled a definitive ranking of them, presumably so nobody else has to such a terrible job.

    The scale goes from 0 to 4, where a level 0 sting is basically jut a kiss from a butterfly, a bee-sting (“the benchmark of sting pain” is level 2) and level 4 stings are so bad that Schmidt only found 4 creatures with that god-given level of cruelty. He described the sting from the Tarantula Hawk as like “a running hair dryer has just been dropped into your bubble bath.”

    There’s a great Straight Dope article on this one that’s worth reading. Just to wince and think of nobel Schmidt gingerly lowering a scorpion towards his tender flesh.

  13. Holmes and Rahe stress scale – Relative Stress of Negative Life Events

    So two psychiatrists, Holmes and Rahe, decided that they would use the power of maths to work out which life events are most likely to contribute to stress-based illness.

    They rate from the innocuous, a “Change in number of family reunions” which contributes 15 Life Change Units (LCU), through “Trouble with boss” (23 LCU), Marriage (50 LCU), “Death of a close family member” (53 LCU), Imprisonment (63 LCU), Divorce (73 LCU) all the way up to the most traumatic, the “Death of a spouse” (100 LCU).

    I feel this scale has real potential for all sorts of one-upmanship: “My trouble with in-laws (29) and sexual difficulties (39) trump your tax Fraud (11) and losing your leg (53)”.




[1] Yeah, ok – weather counts as daily life, so all the disaster ones count. Your life may, one day, rely on them. ^back

[2] Formally: pungency. Peter piper picked a peck of pungent peppers. ^back

[3] Which would be great, except water actually spreads the capsinoids which cause the burning, whereas casein in milk is your best bet for quick relief. ^back