-------- Original Message -------- Subject: Re: Margin error calculation? Date: Mon, 28 Nov 2011 14:40:03 -0500 From: Carmelo Fruciano <[email protected]> To: [email protected] Dear Matias, I'm not sure I understood your question correctly nor I'm clear about the "connection" thing. However, repeating the measurement process multiple times will give you an idea of how "variable" are the measurements. For each linear measurement you could compute the proportion of intra-individual variance produced by repeated measures relative to total variance (this measure is sometimes called repeteability or in other ways, depending also on the field). For the case of two repeated measures, if I remember correctly, this is the same as the correlation between the two measurements (on multiple specimens, of course). I hope this helps, Carmelo morphmet <[email protected]> ha scritto:
-------- Original Message -------- Subject: Margin error calculation? Date: Sun, 27 Nov 2011 13:42:44 -0500 From: Matias Gomez Corrales <[email protected]> To: <[email protected]> Hi All, W´ve been making measurements using TPSDig2, by taking pictures of scorpions samples with millimeter paper on the background. First using the measure option under the image tools to define a scale factor by marking two landmarks using two reference points on millimeter paper whose distance is 20 mm. Then we proceed to landmark our interested points and calculate the distance between them by using the pitagoras formula. Now we need to calculate the margin error on our measurements but we are confused as to how to establish it. Basically we think we need to know what how to make a connection (in terms of measuring error) between the millimeter paper and our measurements made using the TPS. Can you please provide some guidance on this matter? Many thanks, Matias
-- Carmelo Fruciano Post-doc - University of Konstanz - Konstanz, Germany e-mail [email protected] http://www.fruciano.it/research/ ---------------------------------------------------------------- Universita' di Catania - A.P.Se.Ma. Servizio di Posta Elettronica
