Uneven baking is a problem in most kitchens.There are several ways it can be prevented.Uneven baking can be prevented by rotating the pan 180 degrees after two thirds of the suggested time has passed. Cookies will burn if they aren't in the middle rack and would be too close to the heat source.
Bibliography
Martha Stewart
"Chocolate Chip Cookie Recipes." Martha Stewart. N.p., 02 Feb. 2011. Web. 18 Jan. 2015.
Science Buddies
Science Buddies Staff. "Cookies: Can You Blame the Burnt Ones On the Cookie Sheet?" Science Buddies. Science Buddies, 6 Oct. 2014. Web. 18 May 2015 <http://www.sciencebuddies.org/science-fair-projects/project_ideas/FoodSci_p023.shtml>
YouTube
"What Causes Uneven Baking in Cookies? : Desserts & Baking Tips."YouTube. YouTube, n.d. Web. 1 Mar. 2015.
Martha Stewart
"Chocolate Chip Cookie Recipes." Martha Stewart. N.p., 02 Feb. 2011. Web. 18 Jan. 2015.
Science Buddies
Science Buddies Staff. "Cookies: Can You Blame the Burnt Ones On the Cookie Sheet?" Science Buddies. Science Buddies, 6 Oct. 2014. Web. 18 May 2015 <http://www.sciencebuddies.org/science-fair-projects/project_ideas/FoodSci_p023.shtml>
YouTube
"What Causes Uneven Baking in Cookies? : Desserts & Baking Tips."YouTube. YouTube, n.d. Web. 1 Mar. 2015.