In Starship Troopers, Heinlein (through the voice of a high school teacher) explains that value is subjective and mutable: a good chef can take apples and dough and form a delectable pastry that's worth more than its parts, while an incompetent chef can make these ingredients--already wholesome and valuable in themselves--into an inedible, worthless mess.
The Edge of the World is part one of what should have been an impressive high fantasy saga: after all, it has the right ingredients. Anderson is a talented, first-rate writer with a great track record--dozens of published books, many of which I've enjoyed greatly. He has obviously done his homework here, putting in a lot of effort to build an elaborate world to play in: a religious mythos that forms the basis for his major peoples, multiple societies, characters from all over the world. The environment is well chosen, letting the author play with lots of exploration (ships, hot air balloons, overland treks) and novelties (interesting magics, the invention of gunpowder, unusual sea creatures). And the plot is well designed: the story arc (and primary characters) follow the map of the main religion, rediscovering artifacts and searching for ancient continents. How on Earth could all this go wrong?
I'll tell you how: not with a bang does this fail, but with a snore. Halfway through this first book I was completely bored with it, and trudged through only by sheer determination. I even bought the sequel just to prove that I was willing to give Anderson a fair shake, but a quarter of the way through I put it down and never picked it back up.
Ultimately this book lost me because it left me unable to identify with a single one of its main characters. They all had the exact same character flaw: when in desperate trouble, they did...nothing. The hero of an early exploration whose ship was destroyed and who rode home on a sea monster then walked into the mountains for twenty years to herd sheep. His pregnant young wife, who was abducted by a foreign war party and made queen, just sighed and acquiesced. The king who should have set his world on fire to explore and conquer, did practically nothing except grow old and tired and eventually die. Yawn. The only character in the book who was remotely interesting was a madman--but in such a big novel, he was lost in the noise.
Hint to Anderson: next time, make your characters exciting.