(1) An isobar model for kaon photoproduction on the nucleon has been constructed by using an effective Lagrangian technique. The model is constrained by applying SU(3) coupling constants in the Born terms and gauge invariance in the amplitude. A good agreement with available experimental data is obtained. The model is then extended to describe kaon electroproduction data by including the appropriate longitudinal terms.

(2) Photo- and electroproduction processes of K⁺ on the deuteron are investigated theoretically. Modern hyperon- nucleon forces as well as an updated kaon production operator on the nucleon are seen in various observables. Especially the photoproduction double polarization observable C_z is shown to provide a handle to distinguish different hyperon-nucleon force models.