A systematic study of dynamical systems requires finding a series of bifurcation diagrams instead of just cases with different phase plane behaviour. A scheme is developed for identifying experimentally observed bifurcations (transitions) in the dynamic features of a system characterized by two state variables. Maps of experimentally found bifurcation points in a two parameter (operating conditions) plane may be used to estimate the location of singular points and their nature (defining conditions). This information may be used to predict new types of dynamic behaviour and corresponding operating conditions. Moreover, it can be used to develop a simple (qualitative) mathematical model which predicts all the observed dynamic features and transitions.