Results of the test with nine samples of 10 000 artificial clusters using UBVRI photometry with σ = 0.05 mag for the photometric Gaussian errors for each filter. The true metallicity of the models is specified at the extreme right of the figure and the metallicity of the grid used to classify the clusters is specified at the top of panels. Blocks of panels show the derived a) age; b) mass (the total area of each histogram is normalized to one); and c) extinction. In each block, the main diagonal panels are those where the true metallicity and the metallicity of the grid are the same, Z_true = Z_used.