What are the differences between 1) probabillities, 2) possibillities, and 3) plausabillities?
from cheese_greater@lemmy.world to nostupidquestions@lemmy.world on 30 Jun 17:35
https://lemmy.world/post/32279518

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Successful_Try543@feddit.org on 30 Jun 17:45 next collapse

If you flip a coin, the result has two possibilities: It may show either the obverse side (head) or the reverse (tails). These possibilities have equal probability (“50:50”), i.e. in 100 times the coin is flipped, statistically both sides are shown 50 times.

cheese_greater@lemmy.world on 30 Jun 17:46 next collapse

How would you distinguish the 3 terms? Are probabillities and plausibillities roughly analagous)

Blemgo@lemmy.world on 30 Jun 18:28 next collapse

Possibilities are all possible outcomes of a certain scenario. With the example of a coin toss, it’s heads or tails. However, these are dependent on your definition of what you want to observe. For example, at a dice roll, you could define the possibilities as:

  • any number less than 5 is rolled
  • a 5 is rolled
  • a 6 is rolled

Probabilities are attached to possibilities. They define how likely an outcome is. For example, in an ideal coin toss heads and tails have a probabilitiy of 0.5 (or 50%) each.

With my 2nd example, the probabilities would be:

  • any number less than 5 is rolled: 4/6 (or 2/3 or 0.666… or 66.666…%)
  • a 5 is rolled (1/6 or 0.1666… or 16.666…%)
  • a 6 is rolled (1/6 or 0.1666… or 16.666…%)

All probabilities must add up to 1.0 (or 100%), otherwise your possibilities overlap, which is generally not something you want.


Plausibility is a bit more tricky, as it also depends on your definition, namely a cutoff point. You could see the cutoff point as a limit of how much you want to risk. I’ll only examine the example for the coin toss for that. Say you will toss a coin 100 times. This would mean there are 2^100^ possibilities, but we will examine only 2 for this matter:

  • you will get 100 times tails
  • you will get as many tails as heads

Let’s say the cutoff point is 0.01, i.e. 1%. This would make the first possibility improbable, as 1/(2^100^) is far lower than 0.01. The second possibility is 0.5, which is greater than 0.01, and therefore probable.

Successful_Try543@feddit.org on 30 Jun 18:34 collapse

Thank you.

TranquilTurbulence@lemmy.zip on 30 Jun 21:38 collapse

A common dice has 6 possible outcomes. Unless it’s a special D6, it’s impossible to get a zero or some other value outside the usual range of 1-6.

Normally, each side has a probability of 1/6. If it’s a loaded dice, one value will have a higher probability, while the other sides will have a lower probability.

Let’s say you have two dice, you roll them, and hope to get 6 on both of them. It’s possible to get that on the first try, but it’s much more plausible that you have to roll them many times before that happens.

zout@fedia.io on 30 Jun 19:46 collapse

But, it is plausible you didn't flip 50:50 since the 50:50 is on average.

Successful_Try543@feddit.org on 30 Jun 19:57 collapse

Exactly, 50:50 is statistically the most likely scenario (7.96%), while e.g. 51:49 being only slightly less likely (7.80 %). A strongly biased distribution as e.g. 60:40 only has a small probability of 1 %, but is not impossible.

Stillwater@sh.itjust.works on 30 Jun 17:46 next collapse

Probabilities will likely happen.
Possibilities could happen if chances go right.
Plausibilities could, within reason, happen, but are not necessarily likely.

cheese_greater@lemmy.world on 30 Jun 17:48 collapse
  • Prob = > 50%
  • Possibillities = > 0%
  • Plausibillity = >0%…<=50%

?

Stillwater@sh.itjust.works on 30 Jun 17:54 collapse

They’re not just different ranges of probability.

Probable = likely to happen
Possible = able to happen
Plausible = able or likely to happen according to reasonable inference

salacious_coaster@infosec.pub on 30 Jun 17:48 next collapse

Possibility: it can technically happen

Probability: statistically significant likelihood of happening

Plausibility: a possibility that passes the laugh test

cheese_greater@lemmy.world on 30 Jun 17:51 collapse

passes the laugh test

Actually a great heuristic, thanks!

Very plausible response

golli@sopuli.xyz on 30 Jun 17:49 next collapse

My understanding would be:

  • Probabilities: Chance of a certain outcome happening. E.g. Outcome A has a 70% chance B a 20% and C 10%

  • Possibilities: what outcome scenarios exist. E.g. there exist 3 (A B C). Those Possibilities might have a probability associated with them

  • Plausibility: looks at the degree of truth of a statement. So if it logically makes sense and is the correct answer/is what happened. You might make a judgement of the plausibility of a possibility based on the probability of it happening. Say if something has two outcomes one with a 99% chance and the other 1% then that might be the more plausible one. Or if it has no chance, then it might be implausible


Edit: since someone mentioned the example of a coin toss.

Head and tails have a probability of 50% each (for the sake of simplicity I assume it won’t land standing up)

A coin toss has two possible outcomes (possibilities). Head and tails.

Someone says he flipped a coin and got head 1000 times in a row. That’s not plausible with a fair coin because of the low chance of it actually happening (even if there is a indefinitely small chance). As a result you might assume he is either lying or the coin is weighted for that outcome.

Toes@ani.social on 30 Jun 19:01 collapse

A coin toss has two possible outcomes (possibilities). Head and tails.

There is also the extreme implausibility with a <1% probability that it will land on its edge but still more possible than 1000 heads in a row.

Rhaedas@fedia.io on 30 Jun 20:28 collapse

1 in 6000 chance for an American nickel, which has a thicker side than most. Just for others sake. I felt it was far less than just <1% and had to find out.

nimpnin@sopuli.xyz on 30 Jun 18:20 next collapse

Probability is a numeric value between: 0 and 1 of how likely an event is going to happen. Depending on the definition, I would say that possibilities and plausabilities are both events with a nonzero probability. Colloquially, possibilities are more likely than plausabilities I guess. Source: two thirds of a stats phd and C2 level english skills lol

cheese_greater@lemmy.world on 30 Jun 18:51 collapse

when people say its plausible tho, I feel like that means its a bit more likely or they entertain the chance of it happening or being correct more than a mere possibillity tho

nimpnin@sopuli.xyz on 30 Jun 19:30 next collapse

maybe all the stats have eroded any intuition I had for these words

jbrains@sh.itjust.works on 01 Jul 00:06 collapse

Plausible is more like conceivable.

It’s possible that when I slam my hand on the table, it will go through the table, but it’s not plausible. We can’t imagine it actually happening, even though we know it can.

loomy@lemy.lol on 30 Jun 19:12 next collapse
  1. likelihood
  2. is it impossible?
  3. can you imagine it happening, or not?
whaleross@lemmy.world on 30 Jun 20:09 next collapse

Coin toss:

  1. Heads or tails are 50/50 probability.
  2. It is possible that the coin lands on its side.
  3. It is implausible that it splits in two.
Libra@lemmy.ml on 30 Jun 21:18 next collapse
  1. Decent chance of happening.
  2. Is theoretically possible but unlikely.
  3. Could happen, but there’s no data on how likely it is.
CrazyLikeGollum@lemmy.world on 01 Jul 00:51 collapse
  1. Probabilities - The mathematically determined chance that something will happen given a specific scenario.

  2. Possibilities - The set off all things with a >0% chance of happening given a specific scenario.

  3. Plausibility - The outcomes of a specific scenario, that when presented to a reasonable person, that person would determine that they are possible.