Ruben's scale 

Ruben's scale is used in psychology to measure the level of slowness of a human being. When a person finds difficulties understanding or doing things the right way he is evaluated on Ruben's scale depending on how slow he is acting and according to stated average.

He is not getting it even after one hour of explanations. He scores 7.0 on Ruben's Scale.

Ruben's scale by llame December 4, 2016