Cookies!

I'm not much of a cook, but I've taken to making a few things here and there from time to time. One of the recipes I've taken up on using on an occasional basis is this recipe for chocolate chip cookies. The only difference is that I only bake them for about 11 minutes or so; doing them for 13-15, as the recipe suggests, ends up burning the bottom of the cookies. It could be a problem with the oven I have, which may very well overheat when it is baking.