Let's say I'm repeatedly running an experiment where I measure a variable at particular time intervals, but on some of the experiments one potentially affective factor exists, and on others it doesn't - what would be the most appropriate statistical test to figure out if the factor is significantly influencing the variable measured?
e.g. if this was a measurement of bacterial growth - every ten minutes the optical density (which gives a good approximation of cell count) is measured. The experiment is run ten times, five times with a potential growth inhibitor added, and five times without. How to handle that data and get a p-value for the inhibitor having an effect?