Question

A soldier stationed at a base in northern alaska is dressed in his all-white camouflage. he wants to know the exact distance from which another person can distinguish him from the snowbank in which he is hiding. the soldier is concerned with the _______

Answer 1

The answer is: just noticeable difference

In psychology, just noticeable difference refers to a sudden change that can make people's sense to perceive a certain thing differently.

In the case above, the soldier aware that if he move, he would create a movement that cannot be done by a simple snow. He's concerned that the enemy that see it would automatically notice it with their vision and directly aware of the camouflage.