Why does this sourdough recipe call for 2 and 1/3 cups starter? Isn't that too much? The recipe at this popular site says 2 and 1/3 cups of starter and 3 and 1/3 cups of flour, along with water (1 cup). Is there a printing error? Other recipes are about tablespoons, not cups. http://www.culturesforhealth.com/learn/sourdough/how-to-make-sourdough-bread/

Not the video, recipe below the video.
That is quite a bit of sourdough starter, but not extremely so. In sourdough recipes that also include yeast in the loaf, you might see measurements of a cup or less, but a tablespoon of starter in a loaf would be pretty negligible.

The recipe here does not include yeast other than what's in the starter, so 2 and 1/3 cup is not extreme. I watched the video; there is no reason to think that the recipe is in error.