In view of comparison with other models, the parameter optimization is justified be-3-5 6-8 9-11 3-11 Brants et al. (2002) 7. cause other models, e.g., TopicTiling<cite> (Riedl and Biemann, 2012)</cite> , also have parameters (e.g., number of topics for the topic model) which are optimized using cross-validation.