Type of Search	Topic	Explanation
One Aspect of a Larger Topic	Adverse effects of the MMR vaccine	A keyword search retrieves over 900 hits. A MeSH search with subheadings quickly provides focus.
Rare or New Topic	"Baby rattle" pelvis dysplasia	A keyword search is best for rare or new topics. There is no MeSH term for baby rattle pelvis dysplasia.
Complicated Topic	Therapeutic use of ACE-Inhibitors to prevent diabetes	A keyword search here is too broad. A MeSH search helps focus on the relationship between the terms.