The document analyzes user modeling approaches for generating Twitter-based user profiles to support personalized news recommendations. It explores different profile types (tweet-based, entity-based, topic-based), the impact of semantic enrichment, and how profiles change over time and according to temporal patterns. An evaluation shows that entity-based profiles combined with semantic enrichment most improve recommendation quality and that adapting topic-based profiles to temporal context also helps performance. Future work is needed to understand what profile types best support different personalization tasks.