:)
i'll tell you the difference between search and language processing. if you have 10 chapters each highlighting 10 unique points, search works great as the book is basically a sub book of 100 topics.
but for books like medical texts, all chapters have similar sub-headings, so the book is like a table with medical conditions as rows and approaches like pathology, physiology and pharmacology as columns in chapters. this is why simple search throws up massive false positives and is mostly useless.
the complexity in medical field stems not from existence of vast array of unique features but due to having a fixed vocabulary of features in different permutations for distinct conditions. so word level searches are far less efficient than paragraph level searches where the meaning is inferenced by considering every word in its vicinity