key leadership practices, and each statement is cast
on a ®ve-point Likert scale (1=seldom or rarely; 5=very
often). The LPI has been used to measure leadership
behaviours across a variety of organizations, disciplines
and demographic backgrounds. Validation studies
conducted consistently over a 10-year period have
con®rmed its reliability and validity (Kouzes & Posner
1995).
Scores on the LPI have been relatively stable over time.
Furthermore, they have been found to be unrelated to
various demographic factors such as age, marital status,
years of experience and educational level. LPI scores are
also found not to be related to organizational characteristics
such as size, functional area, line vs. staff position.
Internal reliabilities using the Cronbach's alpha range
between 0.81 and 0.91 (Kouzes & Posner 1995).
Reliabilities for LPI-self, range between 0.71 and 0.85
and for LPI-observer range between 0.82 and 0.92
(Kouzes & Posner 1995). Test±retest reliabilities (r)
are reported to be at 0.93 and above (Kouzes & Posner
1995).