Spectral energy distributions (SEDs) of four photometric quasars identified using our ML algorithms (see Sect. 3.3). The NDWFS-Boötes photometry is used to calculate the SEDs. In each case the best-fit quasar template (as derived from the EAZY calculation) is also plotted. Red circles are the photometric points and the blue circles indicate the predicted photometry by the best-fit template. The probability density distributions (PDFs) for each object are shown in the small inset. These PDFs strongly suggest that these objects are quasars located at z >  1.4.