TRAQ to replace QTRA

[Acer ventura]

'Gross errors' and 'misled the court' in on sentence? You must be pretty sure of that or esle you've got a libel case on your hands and might have a starring role in negligence and perjury cases. Can you not just stick to your own points instead of having digs at other people?

 

Hi Jules

 

I'm much more than 'pretty sure' about the levels of risk the experts reported to the court, and this was a critical point in the case (see transcript, second joint statement, and judgment), otherwise I wouldn't have posted it. These are facts and not opinions, and I have been careful with my words; as I was when I was involved in uncovering this.

 

Perhaps you could heed your own advice, rather than having a 'dig', and might find it useful to read document 11 (and 9 as well) in the link I provided before speculating, with selective cut and paste, whether or not you think I'm being 'libelous'.

 

Cheers

 

Acer ventura

[Acer ventura]

David

 

Your Martian does come to mind....would that be 50% uncertain or 100%?

 

Jon

 

PS I do believe you have a slot at the AA Conference - I await to hear it with interest!

 

Hi Jon

 

50% certainty is 100% uncertainty, with the Mars Forecasts! story.

 

And I'm 95% certain I'm presenting at the AA Conference with this:

 

Estimating Likelihood of Failure - A VALID Approach

 

Wednesday Speakers

 

Are you still a QTRA Registered User? If so, you might be interested in a couple of QTRA days out that are being planned at Chatsworth for Saturday 18th July, and Windsor Great Park on Sunday 2nd August. The rough order of play is to have them like the UKTC days out with a social potter and picnic around some marvelous trees, but we’re also planning on running Probability/Likelihood of Failure calibration exercises to harvest the wisdom of the crowd, and I’ll be further road testing VALID. Having messed up a perfect photo opportunity in Sydney earlier this year, I also need some P/LoF calibration photo sequences for the ISA conference in Florida.

 

International Society of Arboriculture

 

Which could be interesting.

 

Cheers

 

Acer ventura

Edited June 6, 2015 by David Humphries
Rule 2

[Acer ventura]

Whilst on precision. I’m sure many of you following this thread will have seen I’ve uploaded a summary document of the TRAQ thread from last year. In it, one of the issues discussed is that a QTRA Probability of Failure (PoF) range 1 (in numbers 1/1 - <1/10) has three of four of TRAQ Likelihood of Failure ranges in it. Imminent and High Likelihood of Failure ‘words’ are parked in the top end of PoF range 1, and the upper values of the Probable ’word’ are in there as well. Now that’s an incredible level of precision, but not obvious because the remarkable accuracy is disguised by the use of words; which can often have a significantly different meaning depending on whoever happens to say or hear them.

 

Having a quick review of this thread to see whether what I posted makes sense afterwards, I realise I've messed up here and momentarily got lost in the fog of words. This:

 

In it' date=' one of the issues discussed is that a QTRA Probability of Failure (PoF) range 1 (in numbers 1/1 - <1/10) has three of four of TRAQ Likelihood of Failure ranges in it. [b']Imminent [/b]and High Likelihood of Failure ‘words’ are parked in the top end of PoF range 1, and the upper values of the Probable ’word’ are in there as well.

 

Should read, and I'll uppercase to identify where I've gone wrong:

 

"In it, one of the issues discussed is that a QTRA Probability of Failure (PoF) range 1 (in numbers 1/1 - <1/10) has three of four of TRAQ Likelihood of Failure ranges in it. Imminent and PROBABLE Likelihood of Failure ‘words’ are parked in the top end of PoF range 1, and the upper values of the POSSIBLE ’word’ are in there as well."

 

Sorry about that.

 

If one of the the moderators could fix this in the ordinal message, or draw attention to the later message that would be great.

 

Cheers

 

Acer ventura

[daltontrees]

Hi Jules

 

I'm much more than 'pretty sure' about the levels of risk the experts reported to the court, and this was a critical point in the case (see transcript, second joint statement, and judgment), otherwise I wouldn't have posted it. These are facts and not opinions, and I have been careful with my words; as I was when I was involved in uncovering this.

 

Perhaps you could heed your own advice, rather than having a 'dig', and might find it useful to read document 11 (and 9 as well) in the link I provided before speculating, with selective cut and paste, whether or not you think I'm being 'libelous'.

 

Cheers

 

Acer ventura

 

I don't doubt you have careful with your words, but that is not the same as them being fair and accurate. You seem to have moved the opinion of 'gross exaggeration' resulting in 'court misunderstanding' ... to ...'gross errors' and 'misled the court'. The former two are opinion, the latter two together seem to me to be accusation of intent by the witnesses.

 

Om the other hand, I did not speculate, I asked a question, affording you the opportunity to retract and get back on track and talk about sometihng other than what everyone by now knows to be your partisan interest in QTRA. You have not retracted, and preversely instead you seem to think that I am having a 'dig'.

 

For the record, if I even need to say it, I did not say you were been libellous. Is there a word for someone wrongly accusing somebody of wrongly accusing somebody of writing something defamatory? If there is, and if I gave a damn about it or about being defamed by you, I might do something about it, but on the balance of probabilities I don't give a damn.

 

If you have something useful to say about trees that isn't a QTRA sales pitch, crack on. I can't stop you, whatever you say, nor is it my job to do so. But it's a free world and if you talk mince, I am just as free to opine that it is mince or that words are being minced.

 

Take care, it's foggy out there...

[Paul Barton]

 

If one of the the moderators could fix this in the ordinal message, or draw attention to the later message that would be great.

 

 

Done.

[Acer ventura]

So the fact that someone has quoted QTRA in Court merely reflects that the expert (or other witness) thought it worthwhile to do so; nothing more. We can say a system has been tested in Court but it's not really the place for testing all aspects of a system - peers, professional bodies and experience in use should be significant parts of the process of testing.

 

I see CAS have Expert Witness Day III coming up this week, with David Lonsdale amongst others, so it might be opportune follow up Jon’s point about QTRA being in court, and what that might mean, a bit further. In Harry Bowen & Others v National Trust, David Lonsdale was the Defendant’s expert and used QTRA to calculate the risk retrospectively. Consequently, the Claimant’s expert witness, Julian Forbes-Laird, decided to produce a supplementary report with the specific purpose of criticising QTRA. David Lonsdale was obliged to respond refuting the criticisms that Julian Forbes-Laird levelled. Having spoken to David about the case and this part of it, IIRC the Judge was not particularly interested in either of the supplementary reports.

 

The supplementary reports are documents 8 & 9, and other documents relevant to the case are here:

 

Quantified Tree Risk Assessment

 

I highly recommend reading David's commentary (document 10) on the case.

 

Cheers

 

Acer ventura

Edited June 8, 2015 by Acer ventura

[Andy Clark]

I see CAS have Expert Witness Day III coming up this week, with David Lonsdale amongst others, so it might be opportune follow up Jon’s point about QTRA being in court, and what that might mean, a bit further. In Harry Bowen & Others v National Trust, David Lonsdale was the Defendant’s expert and used QTRA to calculate the risk retrospectively. Consequently, the Claimant’s expert witness, Julian Forbes-Laird, decided to produce a supplementary report with the specific purpose of criticising QTRA. David Lonsdale was obliged to respond refuting the criticisms that Julian Forbes-Laird levelled. Having spoken to David about the case and this part of it, IIRC the Judge was not particularly interested in either of the supplementary reports.

 

The supplementary reports are documents 8 & 9, and other documents relevant to the case are here:

 

Quantified Tree Risk Assessment

 

I highly recommend reading David's commentary (document 10) on the case.

 

Cheers

 

Acer ventura

 

One thing I have always agreed strongly with from David's surmise, regards the national statistics - in as far as it being, not only important, but essential, to keep the statistics in context.

 

In every presentation I have given relating to tree surveying and appropriate levels of tree management, I always build in a slide that puts the stats into context - and that generally goes along the lines of....

 

Each year between 5 and 6 people in the UK are killed when trees fall on them. Thus the risk of being struck and killed by a tree falling is extremely low. Around 3 people are killed each year by trees in public spaces; but as almost the entire population of the UK is exposed, the risk per person is about one in 20 million.

 

(taken from HSE SIM 01/2007/05)

 

Odds of drowning in a bathtub: 1 in 685,000

Odds of being struck by lightning: 1 in 576,000

Odds of being killed by lightning: 1 in 2,320,000

Odds of being considered possessed by Satan: 1 in 7,000

Odds of getting canonized: 1 in 20,000,000

 

I do this, as I find that often landowners/customers ultimately have no idea of what the output numbers mean following a tree RA, and thus is imperative to keep things in perspective and not have them "knee jerk" into making hefty decisions that in some cases need not be made.

 

For example, in relation to the retrospective QTRA assessment carried out by David on the Felbrigg Beech, he concluded a risk rating of 1:720,000 - meaning that, in context, there was a greater chance of any one of those children either drowning in the bath, or being struck by lightning.

 

Given that we generally tend to understand and accept the risk of drowning in the bath, do we, as either a society or simply as an individual parent, stop our kids from having a bath? Course we don't. Do we keep our children locked away at the first sign of a storm. Not at all, we still kick them out of the door at school time and tell them to stop moaning and grin and bear getting wet.

 

So I think it is imperative to not get swept away with placing an over-importance on numbers that can often be misinterpreted/misunderstood, and use that as a rationale to promote/defame one RA system over another.

Edited June 8, 2015 by Andy Clark

[Acer ventura]

So I think it is imperative to not get swept away with placing an over-importance on numbers that can often be misinterpreted/misunderstood, and use that as a rationale to promote/defame one RA system over another.

 

Hi Andy

 

What you’re saying here makes sense to me until this last paragraph, which looks as though you’re now saying the exact opposite to the previous ones. A number alone can be difficult to understand unless it has context, which is why you’re relating the background level of tree risk as a number, with other numerical risks, to give context and establish proportionality. I do something similar in my presentations, and would be interested in your source for ‘Possession by Satan’ because it’s an amusing risk. It’s also a sufficiently high risk that you couldn’t reasonably impose such an environment on the public that could lead them to screaming “Your mother knits socks in hell!”

 

QTRA is particularly aware of this limitation in communication of risk, which is why the risk number is coloured, with an appropriate advisory about how the level of risk relates to the Tolerability of Risk Framework, so the number has both context and meaning to the risk owner/manager. The point of expressing risk from trees as numbers here is that it’s unambiguous. It can‘t be ‘misinterpreted/misunderstood’. Conversely, if we forsake numbers as a means of defining, measuring or understanding the level of risk, then we’re simply left with the ambiguous wool of words. Without the clarity that comes with numbers, it would not be clear, for example, that a 'Low' risk of death from trees could be higher than playing Russian Roulette, or that a 'Low' risk of death can be higher than a 'Moderate' risk of death (TRAQ). Absence the numbers gained from measurement nailing down the boundaries of the words, providing unambiguous meaning, levels of risk such ‘low’, ‘acceptable’, ‘high’, ‘moderate’, or ‘unacceptable’ can easily be 'misinterpreted/misunderstood' by the risk assessor, and perhaps more importantly by tree owner/manager who is the person that has to make the risk management decision based on the information they have.

 

Cheers

 

Acer ventura

[Acer ventura]

Re-reading Mark’s stuff leads to more head-scratching. Why does ‘operators using the system under license’ not fit ‘the model’? That’s what funds QTRA development, updates, ongoing guidance, information newsletters, and support in the form of dedicated website and private User’s email discussion forum. How is this a bad thing? Does TRAQ fit ‘the model’ better because it doesn’t provide these?

 

I forgot to mention the Registered User also gets to play with the QTRA calculator software, which can be plugged into all manner of tree survey software and databases.

 

Cheers

 

Acer ventura