Recently a guy in the radio was saying that someone was great author if he/she was hard to understand. If you were able to understand him then he was not. I do not agree with such definition but still I cannot tell what makes someone a great author. I think it is more related to weather the author engages you and once you start reading is hard to stop.
One metric for greatness is how long a work survives. If people are still reading Andromeda Strain in 100 years, then it may be considered a great novel.
For example, Charles Dickens's Oliver Twist originally started out as a newspaper serial. It probably wasn't considered great literature at its time. Now, however, it's classic reading material.
Well, one possible test is, as mentioned by others, whether his works are still read a hundred years from now (I doubt that will be the case with Crichton). That's more a practical definition than a theoretical one though, and in my opinion it doesn't necessarily define "great" authors, but lasting ones. All great authors are lasting, but all lasting authors are not great - however, most lasting authors are in fact great authors.
On a theoretical level, I'd put the argument this way: Literary works use lies to achieve one or more of 3 objectives: 1) entertain, 2) expose new ideas, 3) expose deep pieces of ages-old wisdom. I think that in order to be "great", an author needs to at least have a firm foot in the third category.
Michael Crichton was certainly a good author, and very talented at 1) and even 2) sometimes, but did he ever convey any piece of eternal wisdom in his works? I sure didn't find any. This is not to put him down - being a good author is a hard enough achievement. But being great is something else.
Some examples of "great" authors, in my view: Dickens, Shakespeare, Kafka, Thomas Mann, Herman Hesse, Gabriel Garcia Marques, Alexandre Dumas, Victor Hugo, Tolstoy, Dostoievsky, Tchekov, Jane Austen, James Joyce, Hemingway, Romain Gary...
Not all of them are 100 years old, although, sadly, all of them are dead.
the reason people have trouble with concepts like geniuses and great artists is that it is very hard to distinguish anything more than two levels above your own.
Recently a guy in the radio was saying that someone was great author if he/she was hard to understand. If you were able to understand him then he was not. I do not agree with such definition but still I cannot tell what makes someone a great author. I think it is more related to weather the author engages you and once you start reading is hard to stop.