Assess learners' ability to evaluate correctness, stability, convergence, and computational efficiency of numerical methods for stiff ordinary differential equations. Scope: theoretical criteria (consistency, order, A- and L-stability, stiff decay), method families (implicit Runge–Kutta, Rosenbrock, BDF), diagnostic tests (Dahlquist test equation, Robertson problem), and practical metrics (error norms, observed convergence rates, stability regions, step-size control, Newton/Jacobian solves, CPU/time and memory cost). Tasks include proving/identifying properties, designing numerical experiments, interpreting results, and comparing algorithmic trade-offs.