aEstimate from or assumption about data. See web site for further information. #var, number of dependent variables; #exp, number of experimental conditions with different initial conditions and/or input functions; #pts, number of data-points per time series. Noise is added from a Gaussian distribution with SD given as a certain percentage (denoted Noise) of each experimental value. Problem names starting with ‘ss_’ correspond to S-systems. The last section lists problems with real data from biological systems.