In recent years, a number of closed-loop reaction curve methods have been proposed(1-3) for establishing second order dead time model parameters of the open-loop process. The applicability of these methods has been restricted to oscillatory closed-loop test data. In addition, these methods have not been analysed on a comparative basis. The present study, therefore, extends the applicability of these recent identification methods to overdamped closed-loop test data, and evaluates the methods through three typical processes via simulation. The effect of noise is also considered. The results show that the methods due to Bogere and Ozgen(1) and Lee et al.(2) generally provide consistent and accurate models of the open-loop process.