Predictions for the single transverse spin asymmetry A(N) in semi-inclusive
DIS processes are given; non-negligible values of A(N) may arise from spin
effects in the fragmentation of a polarized quark into a final hadron with
a transverse momentum k(perpendicular to) with respect to the jet axis, th
e so-called Collins effect. The elementary single spin asymmetry of the fra
gmenting quark has been fixed in a previous paper, by fitting data on p(up
arrow)p --> pi X, and by assuming that the QCD factorization theorem holds
also when transverse momenta are taken into account. The predictions given
here are based on the assumption that the Collins effect is the only cause
of the observed single spin asymmetries in p(up arrow)p --> pi X. Eventual
spin and k(perpendicular to) dependences in the quark distribution function
s, the so-called Sivers effect, are also discussed.