AMHERST, Mass. - Twenty-six undergraduates from colleges throughout the country are attending an eight-week program at UMass, aimed at encouraging them to earn doctoral degrees in engineering, mathematics, or science. The students, who are primarily from minority backgrounds, are on campus to help conduct research and to gain a better understanding of the path to a Ph.D., as well as the professional life that follows the degree. The project, which is in the second year of a five-year effort, is funded by the National Science Foundation. It began in June and is scheduled to conclude on July 28.