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Did anyone else assume that temperature would be something they'd realize they need to control for? I would even suggest they should have a control group with a
by loceng 13y ago
Did anyone else assume that temperature would be something they'd realize they need to control for? I would even suggest they should have a control group with a fluctuating temperature, as humans go through temperature fluctuations - and perhaps even seasonally alter temperatures.
- mhb 13y agoThen there's also humidity, altitude and who knows what else.
- GotAnyMegadeth 13y agoGravity
- headShrinker 13y agoNot gravity unless they're studying mice in space with some expectation that the subjects are unaffected by the vast different in gravitational pull.
- drivers99 13y ago"Apparent gravity on the earth's surface varies by around 0.7%, from 9.7639 m/s2 on the Nevado Huascarán mountain in Peru to 9.8337 m/s2 at the surface of the Arctic Ocean" http://en.wikipedia.org/wiki/Gravity_of_Earth#Variation_in_gravity_and_apparent_gravity http://en.wikipedia.org/wiki/Gravity_of_Earth#Variation_in_g...
- GotAnyMegadeth 13y agoThat's what I was going for, gravity has probably almost never been controlled for.
- loceng 13y agoMight as well add magnetic field to the list. In the odd circumstance it's possible there could be a large amount of power / electricity in wiring nearby, creating a magnetic field that's different than other test groups, etc..
- gosub 13y agoventilation, illumination type and intensity, human presence.
- saalweachter 13y agoThey did control for temperature. They mandated mice be kept between 20C and 26C, which is between 68F and 78F. Mice live in houses, that's the temperature of houses. 31C is 88F. It's not absurdly hot, but it's hot enough that it's surprisingly hot to me.
- mikeash 13y agoControl for temperature doesn't mean "control the temperature". It means to set up the experiments such that you can detect the effect of temperature. Basically, how did they decided that 20-26C was the right range? If it wasn't by testing differences between mice at colder and warmer temperatures, then they weren't controlling for temperature.
- saalweachter 13y agoYes it does. Controlling a variable means setting up the experiments such that the variable doesn't influence the results. This is typically done by making sure it is the same in both the experimental and control group. Experiments typically control a large number variables, and only vary a small number (ideally, one).
- jonlucc 13y agoMice in a particular experiment tend to be housed in the same room or same rack, with enough circulation in the room to hopefully assure a homogeneous temperature in the room. Therefore, the control animals were likely right next to treatment animals. In this way, one could reasonably say that variations between the groups is not due to the way they were housed. Many other things that are controlled in housing include their feed, bedding, access to water, number of animals in a cage, etc.
- mikeash 13y agoThank you both, I wasn't thinking clearly. I was thinking of the sort of "control for" that involves accounting for differences between groups, but totally spaced on the part where you can just "control for" something by ensuring it's the same.