Update of $\Lambda$ polarization from Z decays

The measurement of Lambda polarization from Z decays with the Aleph detector has been updated with 1995 data and more extensive simulation. The measurement is compared with two models, one based on the simple quark model and one applying SU(3) flavor symmetry on the measured nucleon spin structure function. While the first model is in best agreement with the data, the second one is also consistent, given the uncertainties in the Lambda production mechanism.