Not only is [a half marathon] a good test for the marathon, it is also good for those who feel they were just getting going in a 10K and are physically and mentally primed to go further. A half marathon is a good test of your endurance, without the physical punishment of going the full 26.2 miles. More so even than the 10K, it will teach you about patience, pacing, and how to negotiate a wider range of physical and emotional cycles.