Communities

Writing
Writing
Codidact Meta
Codidact Meta
The Great Outdoors
The Great Outdoors
Photography & Video
Photography & Video
Scientific Speculation
Scientific Speculation
Cooking
Cooking
Electrical Engineering
Electrical Engineering
Judaism
Judaism
Languages & Linguistics
Languages & Linguistics
Software Development
Software Development
Mathematics
Mathematics
Christianity
Christianity
Code Golf
Code Golf
Music
Music
Physics
Physics
Linux Systems
Linux Systems
Power Users
Power Users
Tabletop RPGs
Tabletop RPGs
Community Proposals
Community Proposals
tag:snake search within a tag
answers:0 unanswered questions
user:xxxx search by author id
score:0.5 posts with 0.5+ score
"snake oil" exact phrase
votes:4 posts with 4+ votes
created:<1w created < 1 week ago
post_type:xxxx type of post
Search help
Notifications
Mark all as read See all your notifications »
Q&A

Comments on 25% probability that there was a chance of avoiding injury $\quad$ vs. $\quad$ 25% chance of avoiding injury

Parent

25% probability that there was a chance of avoiding injury $\quad$ vs. $\quad$ 25% chance of avoiding injury

+1
−4

I ask about merely the math behind the last sentence of footnote 71 quoted below. I quote the legalistic sentences thereinbefore for context, but they may be immaterial.

How does "a 25% probability that there was a chance of avoiding injury" differ from "25% chance of avoiding injury"? Alas, my mind is conflating these 2 chances.

71 Though some academics do insist that damages for loss of a chance could have been awarded in Hotson [v East Berkshire Health Authority [1987] AC 750 268]: see Peel 2003b, 627, and references contained therein. An amazing number of academics argue that the fact that the House of Lords awarded the claimant in Hotson nothing means that Hotson is authority for the proposition that damages for loss of a chance of avoiding physical injury cannot be claimed in negligence: see Porat & Stein 2003, 679; Weir 2004, 214–15. As the majority of the Court of Appeal recognised in Gregg v Scott [2002] EWCA Civ 1471 (at [39], per Latham LJ and at [78], per Mance LJ) this is incorrect – the facts of the case in Hotson were such that the claimant simply could not bring a claim for loss of a chance against the defendants. See, to the same effect, Reece 1996; also Hill 1991. Fleming 1997 puts the point quite well (at 69): ‘[A] 25% probability that there was a chance [of avoiding injury cannot] be conflated into a 25% chance [of avoiding injury].’

N.J. McBride and R. Bagshaw, Tort Law, 6th edn (2018), page 280, footnote 71.

In the last sentence, "Fleming 1997" refers to John G. Fleming, “Preventive Damages” in N J Mullany (ed), Torts in the Nineties (LBC Information Services, Sydney, 1997), pp 56-71.

History
Why does this post require attention from curators or moderators?
You might want to add some details to your flag.
Why should this post be closed?

2 comment threads

x-post https://math.stackexchange.com/questions/4693904/25-probability-that-there-was-a-chance-of-avo... (1 comment)
Post Feedback (4 comments)
Post
+4
−1

One is a chance of doing something. The other is a chance of having a chance of doing something.

Here are some analogies that may or may not help, depending on your familiarity with the kinds of situations described.


Analogy 1: A tabletop roleplaying game (RPG).

Your character is sneaking down a dungeon corridor. Unfortunately, you neglected to check for traps, and a poison dart flies out of a concealed hole. You roll the dice to avoid it, but you only have a 25% chance of succeeding at dodging it.

This is the “25% chance of avoiding injury”. $P\left(\mathrm{uninjured}\right)=0.25$.

Having learned your lesson, you start checking for traps as you go. Good thing too, as there’s a pitfall trap straight after the dart trap. The game master secretly rolls your search result; there is a 25% probability that you see it. If you don’t, you automatically fall in. If you do see it, you still have to roll your chance of avoiding it.

This is the “25% probability that there was a chance of avoiding injury”. $P\left(\mathrm{uninjured}\right)=0.25x$, where $x$ is your chance of succeeding on that second roll.


Analogy 2: The lottery ticket

You and three friends buy a lottery ticket together. For some reason, you don’t want to split the prize (if any). Instead, you randomly choose which of you gets any winnings. There is a 25% chance that the recipient is you.

This parallels the “25% chance of avoiding injury”. $P\left(\mathrm{recipient}\right)=0.25$.

But of course, you don’t know if there will be any prize coming. There’s a 25% probability that you’re the chosen recipient, but you still have to wait until the lottery is drawn before you know what you could receive. Your ticket probably only has a small chance of winning a prize.

This parallels the “25% probability that there was a chance of avoiding injury”. $P\left(\mathrm{winner}\right)=0.25x$, where $x$ is the chance of the lottery ticket winning something.

History
Why does this post require attention from curators or moderators?
You might want to add some details to your flag.

1 comment thread

Thanks. $\color{limegreen}{1.}$ Can you simplify your puzzling example of *"Imagine a tabletop role... (3 comments)
Thanks. $\color{limegreen}{1.}$ Can you simplify your puzzling example of *"Imagine a tabletop role...
DNB‭ wrote over 1 year ago · edited over 1 year ago

Thanks. $\color{limegreen}{1.}$ Can you simplify your example of "Imagine a tabletop roleplaying game. Your character is sneaking down a dungeon corridor. Unfortunately, you neglected to check for traps, and a poison dart flies out of a concealed hole. You roll the dice to avoid it, but you only have a 25% chance of succeeding at dodging it."? Please use a simpler example? This role-playing, these dungeons, traps, darts, etc... are too thorny for me, and are adding to my bewilderment. $\color{limegreen}{2.}$ "The game master secretly rolls your search result;" What exactly does this mean?

Tim Pederick‭ wrote over 1 year ago

The scenario described is a game played with dice to introduce an element of chance. If that’s not a type of game you’re familiar with, it’s not going to be helpful. (I chose it because it let me stick with the idea of “avoiding injury”, while also having well-defined probabilities.)

Rather than modify the example, I have added a second analogy that I hope is easier to understand. It’s now about winning money rather than avoiding injury, but the mathematical content is the same.

DNB‭ wrote over 1 year ago

Many thanks! I prefer your second example. English ISN'T my first language, which is why your first example bewildered me.