Definitions for "Main effect"
The effect of one independent variable averaged across the levels of the other independent variable(s).
the effect of a factor on the dependent variable (response) measured without regard to other factors in the analysis.
In general what the overall effect of the treatment is.
Keywords:  lane, steps
Keywords:  observed, input, output, average, level
The average change of the output observed during a change from one level of an input to another level.