STACK is an online assessment system for mathematics and STEM, designed to enable students to answer questions with a mathematical expression, such as a polynomial.
STACK uses the Computer Algebra System Maxima to evaluate expressions.
Before answers are graded, students confirm their answer is interpreted correctly by the system. Invalid answers, like ones with mismatched brackets, are rejected.
Teachers write grading trees that mark answers based on mathematical properties, like "is it factored?"
As an open-source project, users help improve STACK by adding features, translations, bug reports and more. Many users share STACK materials, for example through the ABACUS material bank.
Credits and contributionsABACUS material bank
STACK is trusted by many respected institutions.
STACK is trusted by a number of commercial partners.