Amelanchier

Dared to question? Drama queen. Lets see the links. I suspect they all get answered fairly.

Me neither - probability can be entirely unintuitive! But in that instance I would think that you would multiply each distinct event? That's going to bug me all day now...

Don't you only add independent event probabilities if the events are mutually exclusive? I.e., if one tree failing prevents the others from failing? Seems odd that your would end up with one tree (that had been individually assessed as having a prob. of 0.0001 likelihood of failure) that then was certain to fail when the population was examined?!?

Hang on though. To make the numbers easier, let's imagine that daltontrees has to survey 10,000 trees at a risk threshold of 1/10,000. Each tree would be assessed against that threshold so wouldn't the the population risk be 0.0001x0.0001x0.0001... etc 10,000 times... Which is too small a number for my calculator to show me?!?

Let me google that for you

Interesting! Or is it that 0.8 trees will fail? Now that's confusing

I disagree (surprise). I don't know whether I will get a flat tyre on my bike tomorrow. As I have at least one tyre that at least raises the probability above zero but I think its unlikely that I will be certain to catch a flat (a probability of 1), so its somewhere in between. A useless prediction you say? But its less likely to happen if I don't use the bike, and more likely to happen if I ride through hawthorn hedge flailings. So we can usefully say that there are situations within which we can comparatively assess risk. Now where's the deception in me estimating that I stand a probability of 0.1 of getting a flat if I don't use the bike compared with 0.8 if I ride through thorns? Who have I misled by using numbers to represent my estimation? It would be deceptive if I presented those figures to you as objective measured probabilites; but QTRA doesn't do that. I guess you might feel decieved if you thought I was referring to objective measured probabilites when I wasn't, but if I've been clear enough in my method then that's kind of your problem.

It's quite a leap from "stats can be used to decieve" to "QTRA is fradulent" though isn't it? We could just as equally say; "words can be used to decieve, Albedo's arguement contains words, therefore Albedo's arguement is fraudulent"... Affirming the consequent.

I would guess that's because the saw cuts through the vessels exposing their interior and the latent mycelium to the air whereas when splitting the wood seperates along the thick cell walls with less trauma. Same reason lettuce will brown quicker if you slice it than if you tear it...

Nope, five words too long. QTRA is a subjective assessment using numbers. But I would score that as a 2 on the libel scale...

And it hangs together well although I don't agree with your point.

No worries. Seriously though, I'm glad the cat got a walk!

Fair enough. When you do, just ask yourself if it doesn't just do the exact same thing as QTRA. You add points together (with an element of subjective input) and come up with a figure which you hold up against a threshold for deciding action. I think the biggest issue QTRA faces is that people think that it pretends to offer objective precision and they rightly know that it can't.

So patient describes a headache pain reduction of 20% in absolute terms over two hours when exposure to waffle decreases. Stats from qualitative data

And they are?

Exactly - all QTRA does is put a number on 'negligible' to let you compare it with other risks. Much like Albedo's doctor does (how is the headache anyway?).

Because we'd have to decide where "don't know" starts and where it ends... Though I think it'd be fair to say "don't know" more often.

Ha - I find myself compelled to check or research almost all remotely interesting snippets of info that cross my path. Some of them are even about trees.

Nearly. Power to the people who earn it.

Thankfully (and informatively) google / wikipedia tells me that; "Australia effectively abolished the right of appeal from the Commonwealth Courts by statute, and from the State courts by the Australia Act 1986 (Cth). The Australian constitution still has a provision allowing the High Court of Australia to permit appeals to the Privy Council on inter se questions; however, the High Court has stated that it will not give such permission and that the jurisdiction to do so "has long since been spent" and is obsolete." http://en.wikipedia.org/wiki/Judicial_Committee_of_the_Privy_Council#Australia So I can breathe easy after overreaching the limits of my international law knowledge.

True. Though OP queried the 1/10,000 threshold as well! Exactly. When does red become orange? We'd all point at a different point on the spectrum. Once we put system in place (e.g., the Pantone system) we can demarcate when that transition occurs. Where we put that threshold is subjective and we can argue about whether it should be more red or more orange (or higher or lower) but as long as we put it somewhere we have a reference point - the same is true of the 1/10,000 figure.

I'll ask you in an hour

Nothing wrong with that at all. I have always taken the view that an idea, if it is to be worth anything at all, should be dragged out into the open and given a good kicking. Those that don't get back up should be left to expire... A cheery image but the best I can think of. Your browser decided to secure Youtube and encrypt the link - I took the 's' out of https://... Mine does that sometimes - I haven't worked out why yet.

I would agree about the use (misuse?) of the word risk. But I disagree about the need to quantify it. We need to quantify it to compare it against other things. If we don't compare it properly, we can make some pretty bad decisions!

Good example - the scale is relative to you. He doesn't care if you claim six for something someone else said was a two. He wants to know whether your experience is worse now than it was yesterday and by how much.