An increasing number of users are performing searches on the Web in unfamiliar domains such as healthcare. However, because many users lack domain-specific search knowledge, their searches are often ineffective. An important remedy is to make domain-specific search knowledge in these new domains explicit and available. Towards that goal, healthcare and online shopping experts were observed while they performed search tasks within and outside their domains of expertise. The study: (1) identified domain-specific search strategies in each domain; (2) demonstrated that such knowledge is not automatically acquired from using general-purpose search engines. These results suggest that users should benefit from Strategy Portals that provide domain-specific knowledge to perform searches in unfamiliar domains.