The tangent at any point on a given transfer characteristic of any network, amplifying circuit, transducer, or device. At the point the transfer parameter is the incremental change in the electrical output quantity to the incremental change in the input quantity. The most common transfer parameter used is the transconductance, the transfer characteristic being the output current, I_out, versus the input voltage, V_in. The transresistance is the parameter derived from the characteristic showing the active output voltage, V_out, versus the input current, I_in; other transfer parameters, such as the transimpedance, are derived by plotting the appropriate transfer characteristics.