e^beta? Hell yeah!

17 07 2014

Emma and I got a very helpful response from JMP this morning (below) to a question we’d sent in about logistic regressions (though with more preamable than needed; they could’ve just replied “Yep, you gottit”).

Emma’s reaction? “I’m trying to work out how sad it makes me for being so pleased about this that I actually said (out loud) ‘Hell yeah!’…”

I think it means you’re one of us Emma. Embrace your inner nerd, and learn to love her (just don’t let her pick your clothes).


“The relationship between the parameter estimates in JMP and the odds ratios, depends upon the nature of the independent variable. Assuming you have a binary response variable, the following is true. For a continuous independent variable, the unit odds ratio is equal to e^beta. A unit odds ratio is a comparison of the odds for a one unit increase in the continuous variable. In this case, a negative beta will result in a unit odds ratio that is less than one, while a positive parameter estimate will indicate an odds ratio greater than one. For a binary independent variable, the odds ratio can be calculated as e^(2*beta). This is due to the 1/-1 coding that is used by JMP. Therefore if comparing the level shown in the brackets of the parameter estimate to the level not shown, a negative beta indicates an odds ratio less than one and a positive beta indicates an odds ratio greater than one. For an independent variable that has more than two levels, the odds ratio would be computed using the difference between the betas of the levels being compared. Suppose you want to compare level A with level B. To determine the nature of the odds ratio, you would need to look at the sign of the difference between the parameter estimate for level A and the parameter estimate for level B. The same rules as above would apply. If the difference is negative, that indicates an odds ratio that is less than one”.

Congrats to Pat Turner

16 07 2014

Screen shot 2014-07-16 at 9.47.03 AMCongratulations to Pat Turner on receiving the Canadian Vet Med Association‘s Humane Award at their annual conference last week!

Click here for details.

A mild heart attack …

16 07 2014

… is what I had this morning when I first read the email from Proc Roy Soc and its brutal opening line “your manuscript … has been unsubmitted”. But it had just taken them 3 weeks (3 weeks?? Really???) to notice that I’d not typed Hanno’s email address into the online system. Grrrr.

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Mink enrichment paper accepted!

16 07 2014

Minor revision too – hardly ever get that! Since the writing of it nearly killed us, this is very good news.

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Bit of a stretch

13 07 2014

Maria just sent this image of one of the new young mink in the feeding height experiment, climbing up to eat food (the brown mass) dolloped onto the highest of our levels – 21 inches (a couple of inches taller than large European cages).

Once all the animals have settled in, and she’s recorded the postures they use to feed from all four levels, the next question is: when given a choice, would they rather not have to cling to to a wall with all four feet to eat, or are they so strong and agile they don’t mind at all?

Mink reach

The legacy of Peter Singer’s visit

13 07 2014

Peter Singer visited Guelph (and, briefly, our house) several years ago, but my mother has just posted this picture on Facebook in a fit of maternal showing off to someone.

Not entirely sure what story I’m telling here, but I do remember that he stroked Sophie a lot — and I’m pretty sure she’s not washed her fur since.

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Double congratulations to Alexandra!

12 07 2014

A couple of weeks ago, Alex got offered the Davis job (great news for her, even though I was rooting for Becky). This made Guelph wake up and turn her contractually limited post here into a proper tenure track position. So for a few days, Alex was trying to choose between the two very decent job offers she now had in her hands: not something that happens to many of us in this academic life. She choose Guelph, so yay for us!