UKTC Archive

RE: Tree failure potential assessment study See Tree Risk-Benefit Management Strategy | Update Inbox

Subject: RE: Tree failure potential assessment study See Tree Risk-Benefit Management Strategy | Update Inbox
From: Jim Quaife
Date: Jan 28 2020 08:42:07
Wayne,
" I don't make recommendations or advise or otherwise put my head into a 
liability noose".
This is going to sound like a barbed question, but what do you provide for 
your client?
Jim

-----Original Message-----
From: uktc-request@xxxxxx.tree-care.info 
[mailto:uktc-request@xxxxxx.tree-care.info] On Behalf Of Wayne Tyson
Sent: 27 January 2020 21:01
To: UK Tree Care
Subject: Re: Tree failure potential assessment study See Tree Risk-Benefit 
Management Strategy | Update Inbox

"The essential criterion is to have an ordered thought process." Quite! One
based on measurable facts that can be logged and compared, but with the
full knowledge that GIGA's ugly head can be raised and that debugging of
any system made by humans is a perpetual requirement. It the output is
garbage, that's where "an ordered thought process" comes in, *not* the
intuitive.

" . . . we have absolutely no basis upon which to determining in terms
whether surveying trees for risk is of any use" is exactly why I initiated
my study.

Bear in mind that I am averse to risk *analysis*. The distinction is
*crucial*. My interest is in pushing the sea of ignorance (particularly
mine) back, and that my finger in the dike is only a start. I consider the
whole concept of risk analysis to be voodoo.

I don't make recommendations or advise or otherwise put my head into a
liability noose. I will sometimes make statements about whether or not a
set of defects and characteristics appear to indicate a steady-state,
decline (which might or might not be arrested and reversed), or
strengthening. I might or might not say, at some point, what I would
probably do if the tree were mine.

I am interested in cases where the trend was *clearly* in the direction of
decline, but the facts that made up that *provisional* conclusion were
ignored and resulted in disaster.

We know too little and can never know everything, but that is no excuse for
avoiding a central characteristic of the true professional--continuous
improvement of the science and practice. No one can determine when a tree
is going to fall or a limb is going to come down, but failing to assess
evidence is, as Cicero is said to have said, ". . . a proverbial disgrace."
The goal is not perfection and certitude, it is continuous improvement.
That cannot happen in the absence of actual (critical by nature) thinking
as opposed to merely believing and perpetuating errer.

Wayne


On Mon, Jan 27, 2020 at 12:09 PM Jim Quaife <jq@xxxxxxxxxxxxxxxxx.co.uk>
wrote:

Wayne,
The essential criterion is to have an ordered thought process.  The rest
is standing in front of a tree with a clipboard/tablet using knowledge,
experience and judgement.
I have shied away from methods that require an arb to input figures for
which (s)he can only guess at, or to use some sort of matrix to arrive at
an outcome which still has to be interpreted.  I don't want to be accused
of blowing smoke up David's clinometer but VALID is fundamentally intuitive.
The thinking behind any risk assessment method will necessarily involve
mental gymnastics, but over-complicating its use in the field is
counter-productive.
Your elephant might be the lack of data; mine is that we have absolutely
no basis upon which to determining in terms whether surveying trees for
risk is of any use. As I have posted before, we may be gratified to spot a
defect that has a risk potential and to have it cut off, but there is no
basis other than intuition to say whether had it failed it would have
caused an incident.
Now don't run away with the idea that I am indifferent, because the
opposite is true.
The bottom line is that our primary responsibility is to our insurers, (I
mean secondary - the primary responsibility is to ourselves and our
reputation) and thirdly our clients.  The differential between them is
slight, but it is most definitely in that order.
Of course you are in line with everyone else surveying trees in that the
tree's condition is the first consideration.  The assumption should be that
a tree is safe and one is looking for any factors that might change that.
The assessment of risk follows, but as we have no data and the risk from
trees is so small, one has no option other than to form an opinion.
If you don't, what are you doing there?
Jim

-----Original Message-----
From: uktc-request@xxxxxx.tree-care.info [mailto:
uktc-request@xxxxxx.tree-care.info] On Behalf Of Wayne Tyson
Sent: 27 January 2020 19:40
To: UK Tree Care
Subject: Tree failure potential assessment study See Tree Risk-Benefit
Management Strategy | Update Inbox

This is intended to relate my own perspective on the subject, with which I
understand that some may differ. I intend to post several times, in the
hopes of simplifying the discussion by discussing one issue or coherent
subject at a time, perhaps ending with a general and more comprehensive
discussion of the results. Of course, I entertain no illusions that the
discussion will ever "end," nor, in my view, should it. I *hope* that posts
and responses will be confined to *issues*, with personalities left out. I
am not, however, going to hold my breath.

My study is restricted to assessment of the condition of the tree; it
leaves out any consideration of "risk."

For starters, I believe that the biggest elephant in the room is the
absence of useful data. I know of no central database for the assembly of
relevant data and a sufficiently disciplined practice of data collection
and contribution to a central database that can be readily accessed and
assembled according to the user's needs. "Opinion" is dangerous territory,
especially in the absence of relevant facts.

Feel free to post your own relevant subjects or issues for discussion--I'm
not trying to run the show here.

Wayne
US foreigner



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The UKTC is supported by Bosky Trees arboricultural consultancy
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The UKTC is supported by Bosky Trees arboricultural consultancy
http://www.boskytrees.co.uk/