Study design and data analysis

"Without data, you're just another guy with an opinion." - Anon

But data on their own aren't enough. You need a good scheme to gather the data and proper analysis if your conclusions are to be more credible than another guy's opinion.

This group of web pages grew out of our in-house staff training sessions. They now reflect the material presented during our 2-week stats "Boot Camps" run in co-operation with the Biodiversity Conservation Society of Sarawak (BCSS).

The icon indicates material which we only include in the basic Boot Camp if there is sufficient interest - and time! Topics without hyperlinks are still being worked on.


Rationale
Why is a specialist course (or web site) on wildlife study design and data analysis needed?

  

Teaching approach
We try to get away from sit-and-listen lectures and include lots of practical activities, games and exercises.

R software
We recommend R and use it in most of our courses.

Details of other software packages we use are here.


Drawing random samples and investigating the sample means.

Inferences based on samples
We can rarely measure the whole population or area, so we take a sample and use this to make inferences about the whole. Our inferences will not exactly equal the values for the population, due to random errors or noise introduced by sampling.

Sir Ronald A. FisherTesting hypotheses
We get different results when we draw 2 samples from the same population, so samples from different populations may differ just by chance, not because of the effect we are interested in. We must always ask, "Could it just be due to chance?"

Models and model selection
This is a key topic and underlies most approaches to detection probability

Study design and sample selection
Without good study design, your data may turn out to be of little use. The design stage of a research project is usually skimped as people rush out to start collecting data.

  • What's the question? - different questions need different designs.
  • Review of basic sampling schemes.
  • Using simulations to compare sampling designs.

Bayesian approaches
These methods quantify the uncertainty about estimates and produce information which can be fed into decision-making processes for management.

Checking quadrats on the lawn for ant occupancy.Estimating occupancy
Simple 'presence/absence' data can give useful results, if corrected for detection probability

You may also like to look at the exercises on occupancy at U of Vermont.

Estimating animal densities from transects
'Distance sampling' using line or point transects give estimates of density, and hence numbers of animals in the area of interest.

Using dung or nests to estimate animal densities
The density of animal signs, such as dung piles or nests, can be used, provided rates of production and decay can be estimated.

Estimating animal populations with mark-recapture methods
Mark-recapture methods provide estimates of the number of animals in the area sampled. If that is known, the density can be calculated.

Species richness and diversity
Biodiversity must be protected - even promoted - but is fiendishly difficult to quantify.

Miscellaneous
Various topics which don't fit well under other headings

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Next Boot Camps:

Boot Camps in Malaysia are planned for the 2010/11 wet season. Additional events in Sabah and Lao PDR are mooted. Details TBA.

 
 

 


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wcsmalaysia.org home Text by Mike Meredith, updated 7 April 2010