To address the coldstart issues commonly present in a collaborative ltering (CF) system, most existing crossdomain CF models require auxiliary rating data from another domain; nevertheless, under the cross-website scenario, such data is often unobtainable.
as described previously, we have observed that the hypotheses encoded by the LDa-MF model is too strong as the PMF latent factor is enforced to inherit certain mathematical properties from the LDa topic vector.