On recommendations

I was poking at my goodreads recommendations and noticed a few patterns that I've also seen on Amazon. One was that there are few surprises on there...mostly it's books I've heard about and have some intention of checking out. Another is that almost nothing is based on things I've rated five stars, the books I truly love. It seems the recommendation systems are very good at pulling up the not-bad, three-and-a-half or maybe even four star works. That's fine as far as it goes, but I'm pretty good at finding those. I'd love to have a recommendation system that increased my chances of discovering the truly great that I might otherwise have overlooked, even if that means a greater chance of trying a total dud. Maybe a slider for safe recommendations vs. risky?