Question

An experiment is set up to test whether a particular insect prefer a dark or a bright environment. A chamber with a gradient in light intensity from one end (dark) to the other (bright)

has been made. The experimental hypothesis is:

“There will be a large difference between the number of insect in a dark side and the number in a bright side of the chamber.”

decide for each of the following whether they are potential confounding variables?

A - Varying humidity across the chamber
B - The orientation of the chamber
C - The age of the insects
D - The non-reflective material from which the chamber is made
E - The type of light source used
F - Varying temperature across the chamber

any help, thanks

Answer 1

anything that is different at one end like F or A

Answer 2

What is a confounding variable?

"A confounding variable is a variable, other than the independent variable that you're interested in, that may affect the dependent variable. This can lead to erroneous conclusions about the relationship between the independent and dependent variables. You deal with confounding variables by controlling them; by matching; by randomizing; or by statistical control."

Answer 3

Yes, I think A + F could be confounding variables

probably not B + D + E

B does not change across the chamber
D is irrelevant
E is also irrelevant

probably not C, this does not change across the chamber

thoughts?

Answer 4

A + F = yes

perhaps also "B - The orientation of the chamber"

since this could change between one end of the chamber and the other?

? thoughts? orientation = up/down?

Answer 5

My personal opinion is that orientation make sno difference.
Also I think the type of light is relevant. A bright white light vs a yellow light vs a uv light I think would make a huge difference. I don't know about C since I don't know the behavior of young vs old insects. That might depend upon the kind of insect.