South Australian Branch SSA Meeting Article October 2019

Dr David Baird is a biometrician with 35 years’ consulting experience. David did his MSc in applied statistics at the University of Reading on the nearest neighbour analysis of field trials and a PhD in Statistics at the University of Otago on the design of experiments. David worked with AgResearch for 25 years as a statistical consultant and developed their two-colour microarray analysis suite. David was the statistical consultant on 4 biosecurity eradication programmes and has been the statistical consultant for the NZ Earthquake Commission for the last 8 years. David has been one of the main developers of the Genstat statistical package for over 25 years. So, it wasn’t surprising that David had some very interesting cases to present in a very entertaining way.

One of the first project’s David worked on was a sheep starvation project where sheep were given different levels of food and then killed so their organs could be weighed, and growth rates measured. Such an experiment is unlikely to pass ethics standards of today. Unfortunately, the data was never kept or published. David emphasized the need to include good data management practices and store data in readable formats.

David’s talked about his experiences with experimental designs for animal and field trials, eradication programs on introduced moths, biocontrol program for weevils, impacts of pasture endophytes on animal performance and analysis of two-colour microarrays. Like many statistician’s problems such as lack of randomization, data cleansing, inability to replicate results, differences between statisticians and scientists meant solutions were needed to provide data driven results.

The most interesting work was on financial estimates from the Christchurch earthquakes in order to estimate the EQC Liability so that settlements for damaged houses could be expediated. An initial survey gave an NZ$2.86 billion estimate of total property damage. However, there were multiple earthquakes which meant new surveys, resulting in a final cost estimate of NZ$8 billion. An estimate of the total reimbursement to EQC from reinsurers using nearest neighbour methods was developed and another validation survey was used reach agreement between the two parties.

For more information contact david@vsn.co.nz .

By Paul Sutcliffe