Average W₈₀ binned on a plane of M_⋆ vs. L_{[O III]}. The bins have a size of 0.3 dex in each parameter, colored by the strength of the W₈₀. The scatter dots show the distribution of a specific galaxy population and the line shows a 1D polynomial fitted to the location of the SF galaxies. The green arrows in the plots illustrate the gradient change of W₈₀ in the parameter space, with the arrowhead indicating the direction and the arrow’s size representing the magnitude.