UKTC Archive

RE: Tree risk management

Subject: RE: Tree risk management
From: David Evans
Date: Nov 25 2008 17:26:11
<<I believe that is the spin that Bartletts have put on the results of the 
trial. I'm not sure that the person conducting the trial is entirely happy 
with the way Bartletts have presented things though.>>

Indeed Chris

Here's the AA article.

<<Tree Risk Assessments What Works and What Does Not

Tree risk assessments have become a commonplace activity for many UK 
arborists. As part of a Master Degree research project at The University of 
Melbourne Australia 23 qualitative and quantitative tree risk methods 
commonly used throughout the world were assessed, and from these 15 were 
further analysed. In a later trial, twelve experienced arborists used eight 
methods to assess eight different trees in varying urban situations. Of all 
the systems evaluated the “winner” in terms of accuracy and simplicity was 
that developed by Drs Tom Smiley and Bruce Fraedrich of the R.A. Bartlett 
Tree Research Laboratory. For full details and for a free copy of the 
Melbourne research please refer to Google: Tree Risk Assessments – What Works 
and What Does Not or contact the author direct>>

'Can We Tell?', was also importantly missed off the end of the title as well. 
 I don't know who the author of the article is, but despite appearances it 
wasn't Martin Norris who was doing the research.  To say his research was 
used out of context here is an understatement to say the least.  Here's 
Martin's message on the QTRA forum in response earlier this year.


"I would like to clarify what appears to me to be an out of context use of my 
research in a small article published in the AA Newsletter (Issue 142 Autumn 
2008). The article is not sourced, however, it certainly was not written by 
me and no one from the AA News contacted me to check the accuracy of what was 

The attached document is a summary of the research data quoted in that 
article and places it in context. Anyone wanting further clarification is 
free to contact me.

I will also be writing to the AA."


His letter to the AA is too large a file and to attach so I have cut and 
pasted the second paragraph because the first is repeat of the above and the 
rest relates to graphs.


"Firstly, there is no ‘winner’, I never rated or ranked any method, merely 
presented the data, secondly this article refers to one question that was 
asked of each assessor for each method and each tree assessed, the question 
asked was:
“Rank how well you believe the rating reflects the risk”. With 1 being very 
poor and 10 being very accurate. It never sought to reflect accuracy or 
simplicity; in fact, no such opinion was sought from the assessors. In 
relation to assessing methods for accuracy I have yet to devise just how that 
would be done."



Acer ventura

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