This shouldn't surprise you, but if the effect is large and real, you don't need large sample sizes to prove something. As an example, a loaded die that always

This shouldn't surprise you, but if the effect is large and real, you don't need large sample sizes to prove something. As an example, a loaded die that always comes up with 6. After 18 straight 6's in a row, you are more than assured that you have a loaded die. I imagine that a rational person is convinced long before the 18th 6. The point is: large samples are only needed to measure small effects. Most studies nowadays need large samples because the large effects are low hanging fruit and were noticed quickly (in the past). Meanwhile, finding a single black swan proves that not all swans are white. This study proves that in even a small selection of scent dogs, you are going to have dogs which are highly affected by handler signals. You might be able to use the methods of the paper to exclude dogs which pick up on handler signals and therefore improve the training regimen of scent dogs, there is no evidence to support this possibility however.