Impulsiveness questionnaires I6 and I7 were subjected to psychometric
analysis concerning dimensional structure, internal consistency, and s
tability over time utilising responses of 2 423 adolescents (I6) and 2
277 adults (I7). Using exploratory methods, items, which did not belo
ng to psychometric family, were excluded and internal structure of the
shortened versions of I6 (48 items) and I7 (38 items) was tested. LIS
REL 7 confirmatory factor analysis results supported hypothesized thre
e-dimensional model for the I6(48) and I7(38) as well. Internal consis
tency of the questionnaires range was 0.67-0.94 and stability over tim
e (ten-week-interval) range was 0.59-0.77. The instruments scales inte
rcorrelation matrices, correlation between I6(48) vs. JEPQ(60), I7(38)
vs. EPQ/A is presented. Means and standard deviation of the I6(48) an
d I7(38) scales scores are given with respect to age intervals and gen
der.