In this talk, we prove a generalization of the del Pezzo-Bertini classification of varieties of minimal degree to higher secant varieties of minimal degree. It states that higher secant varieties of minimal degree are mostly divided into two classes: scroll type and Veronese type. Its proof is based on methods of gluing some 1-generic matrices. We also present some simple examples to explain our result. This is a joint work with Prof. Sijong Kwak.