Benjamin Bloom

In 1956, Benjamin Bloom headed a group of educational psychologists. 

Together,  they developed a classification of levels of thinking  behaviors thought to be important in the processes of learning.

This became a taxonomy that included the three domains; cognitive,  psychomotor, and affective.

The following are the six levels of thinking:

1- Knowledge 4- Analysis
2- Comprehension 5- Synthesis
3- Application 6- Evaluation