Section Fivetraining—appear to be very robust in their ability to enhance
firm performance in widely varying settings. Thus, there are
some practices that are almost universal best practices.
Nonetheless, it is easy to overestimate the impact of individual
practices because other practices also make simultaneous
contributions to firm performance. Because of these combined
effects, it has been argued that systems of complementary
human resource practices should have substantial impact on
firm performance because of synergies. The research shows
that such systems do indeed have a substantial impact on firm
performance. Nonetheless, the evidence on whether systems of
practices produce greater impacts on firm performance than
individual practices has been mixed, although methodological
limitations may have prevented more consistent results for the
superiority of systems of practices.
Finally, the current research has examined the impact of
contingent implementations of human resource practices and
systems of practices. While there are some mixed results, there
is substantial support for the proposition that human resource
practices and systems of practices provide even greater impact
when they are matched to the firm’s strategies, organizational
culture, con-text, and other human resource practices. Again,
some of the mixed evidence may be a result of methodological
challenges. There is substantial support for the contingency
perspective that correspondence or fit between human