Ecolog:
What are the uses of cover data, from the most common applications to the
most sublime and rare?
WT
- Original Message -
From: "Liz Pryde"
To:
Sent: Wednesday, November 30, 2011 3:25 PM
Subject: Re: [ECOLOG-L] Transformation of percent cover data for power
anal
Hi Brian,
I've been encountering this percent cover issue for a while. Unfortunately
my data was all based on Braun-Blanquet estimates so analysis has been
tricky. I converted to midpoint percent estimates (not strictly legitimate
but served the purpose) and then had the same problem you did.
I'v
Hello all,
For advice on the use of the arcsin transform, I
recommend the following paper:
http://www.esajournals.org/doi/abs/10.1890/10-0340.1
The title itself is worth poking the link.
David Schneider
Quoting Jordan Marshall :
> Brian
>
> I use arcsin(square root(proportion)) anytime I'm d
Brian
I use arcsin(square root(proportion)) anytime I'm doing analysis of
percent data. The reason may not be justified for the type of simulation
your running, which I'm not familiar with. I use this transformation
since percent data is inherently not normally distributed.
Arcsin(sqrt(proportion)
Hello ecolog,
I am working on a power analysis simulation for long-term forest monitoring
data, with the goal of documenting our power to detect trends over time.
The simulation is based on a repeated measures hierarchical model, where
future data is simulated based on the initial data set and a
