The original PSS consists of 14 items that are purported to form a unidimensional scale of global perceived stress.
2.
It is a 22-item unidimensional scale which is based on needs-based quality of life theory.
3.
The HSP Scale, initially ( 1997 ) a questionnaire designed to measure SPS on a unidimensional scale, was subsequently decomposed into two, three, or four factors or sub-scales.