Statistics for the derivation of photometric redshifts, using the training + testing SDSS samples. Left column plots correspond to a PS-based selection, right column plots correspond to a zConf selection (see Sect. 5.1). First row: percentage of outliers; second row: normalised median absolute deviation; third row: percentage of rejected sources after filtering; fourth row: percentage of rejected sources that are not outliers. Blue circles correspond to ten filters samples (ugrizJHKW1W2), green traingles to seven filters samples (ugrizW1W2), orange crosses to eight filters samples (ugrizJHK), purple squares to five filters samples (ugriz). Solid lines and symbols correspond to extended sources samples, dashed lines and empty symbols to point-like sources samples. Lines are included just for visualisation improvement.