David is the Director of VALID (www.validtreerisk.com) VALID is a not-for-profit that's dedicated to improving and sharing how we go about managing and assessing tree risk. David has previously worked as a Climbing Arborist, Yellow Pages Binder, Arboricultural Lecturer, Mud Volleyball Pitch Curator, and Consulting Arborist – though not necessarily in that order.

Taking the Defect out of Tree Risk Assessment
The D in VALID is changing from Defect to Decay. In this talk, I'll explain why this matters. And reveal how we've taken the Defect out of tree risk management and assessment altogether.

VALID is a structured tool for making better decisions about Likelihood of Failure uncertainty during tree risk assessments. It stands for.

Vitality

Anatomy

Load

Identity

Decay

Each heading breaks down into three subcategories, covering all the factors that increase or decrease the likelihood of failure. At its simplest, VALID is a practical checklist. At a deeper level, it tackles the most challenging part of a tree risk assessment. What's the Likelihood of Failure?

Likelihood of Failure is the part of a tree risk assessment that carries the highest uncertainty and the widest range of opinions. You'll see how VALID reduces uncertainty by promoting good decision hygiene, cutting through the noise and variance that often cloud assessments.

Lastly, I'll share lessons learned from across the UK, Australia, New Zealand, and the USA. You'll hear what hundreds of Arborists taught us by playing 'Likelihood of Failure Club' in the field. And how these insights sharpen your ability to make tough and defensible decisions where it matters most.