Time-resolved terahertz spectroscopy has become a widely used
experimental tool for the investigation of ultrafast dynamics
of polar systems in the far infrared. We have recently proposed 
an analytical method for the extraction of transient two-dimensional
susceptibility from the experimental data [H. Nemec et al., J. Chem. Phys.
117, 8454 (2002)]. In the present paper the methodology of optical
pump-terahertz probe experiments is further developed for direct
application in realistic experimental situations. The expected
two-dimensional transient response function is calculated for a number
of model cases (including Drude dynamics of free carriers, harmonic
and anharmonic oscillator modes); these results serve as a basis for
the interpretation of experimental results. We discuss also the cases
where only partial (one-dimensional) information about the system
dynamics can be experimentally obtained.