1) What are the mechanisms through which high school opportunity structures link to student choice of STEM major and college destination? 2) To what extent and in what ways do high school opportunity structures differ in schools with a large upper/middle class White population versus a comprehensive urban school (with a STEM focus) with a high population of poor and working class students of color? 3) To what extent do the mechanisms through which the high school opportunity structures link to college major choice and college destination differ in the two schools under investigation?