4 ms·

I am a native English speaker and this annoys me as well. 200 times less sounds more impressive than 99.5% less even if it's kind of ambiguous. Same with saying

I am a native English speaker and this annoys me as well. 200 times less sounds more impressive than 99.5% less even if it's kind of ambiguous. Same with saying it only needs 1/200th the amount. They want big numbers in the headline and people will figure out what they meant.

hinkley 4y ago
It’s even more ambiguous when people say “200% faster”. What does 50% faster mean in a world where people can say 200% faster with impunity?
- aordano 4y ago
  200% faster means 3x the nominal speed: You're adding speed ("going faster"). You're adding a 200% of speed, which is twice the nominal speed (the 100%). Given the nominal speed is 1x and you're adding 2x, you end with triple the magnitude of the original nominal speed.
  - deleted 4y ago
    [deleted]
  - hinkley 4y ago
    You've dodged the question mark. What does 50% faster mean? What does 67% faster mean? What does 75% faster mean? I'm using the exact same terminology, so splitting hairs on phrasing isn't going to work for me.
    - fragmede 4y ago
      50% faster means original speed plus 50%, or 1.5x
    - mattkrause 4y ago
      Something crawls along at 1 m/s. After some clever engineering, it now runs 50% faster. Its speed is now 100% (baseline) + 50% (improvement) = 150% of 1 m/s (original speed) = 1.5 * 1 m/s = 1.5 m/s The budget option runs 20% slower than the original model. Its speed is 100% (baseline) - 20% (derating) = 80% * 1 m/s (original speed) = 0.8 m/s.
    - aordano 4y ago
      As sibling comments said, 50% faster means adding 50% of the nominal speed, so it's 1.5x the original magnitude.
  - stormbrew 4y ago
    It would be nice if this were the universal meaning of this phrasing but people do use it to mean both "twice as fast" (2x) and "faster by double the original speed" (3x). People will rail about them using it wrong but it's pretty useless when you have to basically guess whether people subscribe to your definition of "right" before you can understand something.
jacobolus 4y ago
The only reason to have “per cent” (%) as a concept is because decimal fractions weren’t invented yet when per cent was first used; until the past few centuries arithmetic was almost exclusively done in terms of integers or ratios (or various mixed units depending on the material being measured). Using 1/100 as a generic unit was a work-around to make numbers less than one easier to compare and recognize by turning them into 2-digit whole numbers instead of needing to do a careful computation to judge between say 5/13 vs. 3/8. There’s not really any particular advantage to saying 0.005 of the amount (or 1 – 0.995 of the amount) vs. 200 times less. Personally I find it significantly less clear (though not really any more or less “impressive”), because doing mental decimal arithmetic takes some extra effort and leaves more room for confusion. That is, it is easier to reason about multiplying or dividing some quantity by 200 vs. multiplying or dividing by (1 – 0.995). But the two numbers are reciprocals; this is grade-school rational arithmetic, not some kind of trick.

hinkley 4y ago

It’s even more ambiguous when people say “200% faster”. What does 50% faster mean in a world where people can say 200% faster with impunity?

aordano 4y ago
200% faster means 3x the nominal speed: You're adding speed ("going faster"). You're adding a 200% of speed, which is twice the nominal speed (the 100%). Given the nominal speed is 1x and you're adding 2x, you end with triple the magnitude of the original nominal speed.
- deleted 4y ago
  [deleted]
- hinkley 4y ago
  You've dodged the question mark. What does 50% faster mean? What does 67% faster mean? What does 75% faster mean? I'm using the exact same terminology, so splitting hairs on phrasing isn't going to work for me.
  - fragmede 4y ago
    50% faster means original speed plus 50%, or 1.5x
  - mattkrause 4y ago
    Something crawls along at 1 m/s. After some clever engineering, it now runs 50% faster. Its speed is now 100% (baseline) + 50% (improvement) = 150% of 1 m/s (original speed) = 1.5 * 1 m/s = 1.5 m/s The budget option runs 20% slower than the original model. Its speed is 100% (baseline) - 20% (derating) = 80% * 1 m/s (original speed) = 0.8 m/s.
  - aordano 4y ago
    As sibling comments said, 50% faster means adding 50% of the nominal speed, so it's 1.5x the original magnitude.
- stormbrew 4y ago
  It would be nice if this were the universal meaning of this phrasing but people do use it to mean both "twice as fast" (2x) and "faster by double the original speed" (3x). People will rail about them using it wrong but it's pretty useless when you have to basically guess whether people subscribe to your definition of "right" before you can understand something.

jacobolus 4y ago

The only reason to have “per cent” (%) as a concept is because decimal fractions weren’t invented yet when per cent was first used; until the past few centuries arithmetic was almost exclusively done in terms of integers or ratios (or various mixed units depending on the material being measured). Using 1/100 as a generic unit was a work-around to make numbers less than one easier to compare and recognize by turning them into 2-digit whole numbers instead of needing to do a careful computation to judge between say 5/13 vs. 3/8. There’s not really any particular advantage to saying 0.005 of the amount (or 1 – 0.995 of the amount) vs. 200 times less. Personally I find it significantly less clear (though not really any more or less “impressive”), because doing mental decimal arithmetic takes some extra effort and leaves more room for confusion. That is, it is easier to reason about multiplying or dividing some quantity by 200 vs. multiplying or dividing by (1 – 0.995). But the two numbers are reciprocals; this is grade-school rational arithmetic, not some kind of trick.