A problem encountered in statistical analysis when your two groups (or however many you have) both have such low scores on whatever measurement you use that you couldn't possibly tell the difference between them even if there was one. This problem occurs because statistical tests compare two populations by comparing their means on whatever measurement you choose, and seeing if the variances of the samples are large enough that they might both be from the same population. So, if all of your scores are really low, then your means will be very similar and so you might wash out any effect that there might be. The solution is generally to use a less difficult test.

This node was created by cutting and pasting text from the ceiling effect node and changing high to low and more to less. This is arguably lame. The alternative was just to point to the ceiling effect node and say "it's like that in reverse", but I decided that that was definitely lame and I'd prefer the solution that was only arguably lame.