Psychophysiological measures are a useful complement to self-report or
behavioral measures because they can assess Fundamentally different p
rocesses or more sensitively assess the same processes as those target
ed by other types of measures. To be maximally beneficial, psychophysi
ological measures must meet the psychometric criteria that are commonl
y applied to self-report or behavioral measures. Empirical findings to
date indicate that the temporal stability of psychophysiological meas
ures thought to assess individual differences is variable and that res
earchers should devote more attention to systematic assessment of reli
ability, stability, and generalizability. The most critical psychometr
ic issue involves construct validity and the establishment of linkages
between psychophysiological measures and specific psychological proce
sses. Several methodological and conceptual reasons for the difficulti
es that researchers encounter in the attempt to establish such linkage
s are discussed. Methodological guidelines for maximizing the reliabil
ity, temporal stability, and psychological meaningfulness of psychophy
siological measures are proposed.