Well, typically open book tests are designed with that ability to search in mind, so the problems are much harder and designed to test understanding rather than memorization. They often are also much longer, so you cannot just search for everything and still get a full score.
ignormies|3 years ago
Simply knowing a generic fact (e.g. "the Civil War began in 1861" or "the atomic mass of Oxygen is 15.999u") is not sufficient. One needs to know how to use that information.