TRAQ to replace QTRA

[daltontrees]

I certainly don't see it as an indication that CAS is implying one system is "better" or "worse" than the other, as the thread seems to have degenerated to. It is simply their choice, in relation to the aims of their organisation.

 

Degenerated? It's all just good-natured chat. On a forum where half the posts are about what people are watching on the telly or having for their dinner, it is relatively speaking refreshing to discuss tree issues with fellow tree-ists, however regressive the chat seems.

 

Good point about what the A in CAS stands for, by the way. Although |I don't think I'll ever get comfortable with Arborist being used the american way.

[Andy Clark]

Degenerated? It's all just good-natured chat. On a forum where half the posts are about what people are watching on the telly or having for their dinner, it is relatively speaking refreshing to discuss tree issues with fellow tree-ists, however regressive the chat seems.

 

Good point about what the A in CAS stands for, by the way. Although |I don't think I'll ever get comfortable with Arborist being used the american way.

 

Ok, perhaps the wrong choice of word - how about "Evolved".

 

Agreed re the Arborist word. Although at least the yanks do have one word that progresses through their entire industry hierarchy - Climbing Arborist, Consulting Arborist, Municiple Arborist etc.

 

With our free-for-all of an industry over here, we can't even agree on a common job title for most roles...... Climber, Tree Surgeon, Technician, Arboricultural Consultant, Arboricultural Groundworker, Groundsman, Tree Officer, Arboricultural Officer, Landscape Officer......

 

Potato Potato.

Edited June 3, 2015 by Andy Clark
Typo

[kevinjohnsonmbe]

Degenerated? It's all just good-natured chat. On a forum where half the posts are about what people are watching on the telly or having for their dinner, it is relatively speaking refreshing to discuss tree issues with fellow tree-ists, however regressive the chat seems.

 

 

 

Good point about what the A in CAS stands for, by the way. Although |I don't think I'll ever get comfortable with Arborist being used the american way.

 

 

 

Not contributing but a keen observer from the touch lines, gaining info from the thoughts & experience of others whilst trying to decide which path to take. Enjoying the thread!

[Andy Clark]

Not contributing but a keen observer from the touch lines, gaining info from the thoughts & experience of others whilst trying to decide which path to take. Enjoying the thread!

 

I think the wise man would be one who looked at all these different methodologies, be it risk assessment, valuation, or whatever, and had a good working knowledge of all.

 

They are of course merely tools, and the more tools you have in your bag, along with the knowledge and experience of how/when to use them, the wider and deeper the pool of what you can offer to your customers.

 

[Paul Barton]

Thanks for your comments David. I'm glad this topic is being discussed again before the next CAS meeting where it will be on the agenda. Unfortunately I haven't got time to comment much further at the moment but will have a closer look when I get home next week.

[Acer ventura]

Acer,

 

An earlier post from Paul B contained an explanation by Mark Cheter of CAS -

The salient point to take I think, is with CAS being the Consulting Arborist Society, but QTRA however being open/applicable/achievable to non arbs - thus, "QTRA does not an Arborist make", and thus CAS can not necessarily safely accredit a QTRA user as even being an Arborist, let alone a consulting level one.....

 

Hi Andy

 

Thanks for your post. I thought I'd deal with this first before popping back to clarify some other things about how the Visual Tree Assessment - Estimating Probability of Failure day ties in with QTRA.

 

I had read Paul's post, hence my confusion. I think I've ended up with the same level of bafflement about it as Jules. A QTRA Registered User cannot join CAS without the requisite arboricultural accreditation (level 4), which is at a higher level than is required to attend TRAQ (level 2). So the non-arborist QTRA User cannot be an issue with Arboricultural Professional Competencies (APC) because they wouldn’t be able to join CAS. Similarly, a TRAQ accredited level 2 arborist wouldn't be able to join.

 

TRAQ however is tree specific' date=' with training only open to peeps with Arb experience and quals, so thus more closely mirrors the aims of the society. [/quote']

 

So CAS is devaluing QTRA as an APC, or it doesn’t fit the model, because it trains non-arborists in basic tree risk assessment?

 

I certainly don't see it as an indication that CAS is implying one system is "better" or "worse" than the other

 

It isn’t even an ‘implied’ indication of ‘better’ or ‘worse’. CAS is clearly saying TRAQ IS a BETTER tree risk assessment method than QTRA because after 10 years they are aiming to drop QTRA as an APC and replace it with TRAQ.

 

It is simply their choice' date=' in relation to the aims of their organisation.[/quote']

 

Now, this I don’t have problem with because it’s their organisation and they can do as they please. If CAS simply said we prefer TRAQ to QTRA that would be fine, but it’s the reasons in Mark Chester’s piece that I struggle with because some of them are simply wrong, and others don’t seem to make sense.

 

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?

 

Cheers

 

Acer ventura

Edited June 4, 2015 by Acer ventura

[Acer ventura]

Arborists (call them what you will if you don't like the term) have a tendency to avoid or divert this sort of debate with the "well someone used it in Court, so it must be OK" argument. Remember, any system - risk assessment, valuation, root growth or other technical matter - got into Court because an expert took it in. Barristers and judges can apply common sense but are unlikely to engage on technical details. The credibility of any system in Court relies on a number of factors - its provenance, its widespread acceptance, its usefulness. If two experts agree in Court over the use of any system the Court (Judge, jury, barristers/advocates (for those North of the border) may still disagree).

 

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.

 

Hi Jon

 

Good points. The court can be hostage the experts it gets. QTRA was used by both experts in the notorious 'Poll' case (that led to the formation of the National Tree Safety Group). Unfortunately, both experts made gross errors in the application of QTRA and therefore misled the court about the level of risk attached to the Ash stem.

 

Document 11 in the Poll section here:

 

Quantified Tree Risk Assessment

 

Cheers

 

Acer ventura

[daltontrees]

Hi Jon

 

Good points. The court can be hostage the experts it gets. QTRA was used by both experts in the notorious 'Poll' case (that led to the formation of the National Tree Safety Group). Unfortunately, both experts made gross errors in the application of QTRA and therefore misled the court about the level of risk attached to the Ash stem.

 

Document 11 in the Poll section here:

 

Quantified Tree Risk Assessment

 

Cheers

 

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?

[Acer ventura]

 

The point was, QTRA is a scoring system but PTI is so much more than that and doesn't actually require the use of a quantified system. This is re-enforced by the fact that Cheshire Woodlands actually recommend that candidates do the VTA course the day before QTRA to cover that aspect.

 

PTI is more about VTA and the legal system, recording data, etc, rather than scoring. I thought TRAQ was more along that line but I may be wrong? Why not do both was my point but I think Paul covered that with the answer about the lack of an exam.

 

Hi Chris

 

A bit more clarification. QTRA generates a colour-coded probability that the risk owner/manager can compare to the Tolerability of Risk Framework, so I'm not comfortable calling it a 'scoring system'. Quantitative would be better.

 

The legal context is a key element and is built into QTRA in the form of the risk assessment parameters and risk management guidance for advisory risk tolerance thresholds.

 

TRAQ is trying to do something similar in terms of risk assessment but qualitatively (with words not numbers). However, it diverges significantly at the risk management level because the risk owner/manager has to choose one of the TRAQ outputs of Extreme, High, Moderate, or Low as their risk tolerance threshold, which effectively becomes risk management policy.

 

The ‘Visual Tree Assessment - Estimating Probability of Failure’ day is paired with QTRA and those attending QTRA are strongly advised to attend both. However, both days stand alone. The ‘Estimating Probability of Failure’ day is entirely focused on that one element of tree risk, though there are some risk calculations in the field exercise as well. It's the most uncertain part of the risk assessment, hence dedicating a day to looking at the underpinning principles on which it is built, and calibrating PoF range opinions in the field.

 

It's a curious thing that in the UK in particular (it's not the case in other countries), it's regularly the case that some arborists attending QTRA think they don't need the ‘Estimating Probability of Failure’ day because they know ‘VTA’. However, during the field sessions on the QTRA day when we're calibrating Probabilities of Failure, many realise the value in this and wished they're signed on for day two as well. QTRA has tried to address this with a revised description of the day here.

 

Other Training Workshops

 

I’ve also attached an old QTRA Newsletter where I wrote a piece that describes in much more detail what happens on the ‘Estimating Probability of Failure’ Day.

 

As for how PTI relates to risk assessment. I’ve never been entirely clear how it deals with the risk assessment side of things. I see value in the contents, but for all the tree inspector’s knowledge of tree law, biology, decay fungi, VTA, recording data and the like, at the end of the inspection the inspector is still going to be making some form of risk assessment decision, and this has to relate to the risk management tolerance thresholds of the owner/manager.

 

Cheers

 

Acer ventura

QTRA Newsletter Issue 14.pdf

[Jon Heuch]

‘Estimating Probability of Failure’ is the most uncertain part of the risk assessment

 

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!