Comparison between the Herschel and ISO line fluxes, i.e., the ratio of the Herschel and ISO measurements for [Cii] (top), [Oi]₆₃ (middle), and [Oiii]₈₈ (bottom) as a function of Herschel line luminosities. The mean and standard deviation of the Herschel-to-ISO flux ratio is indicated in the top left corner of each panel. The best-fit line and a perfect one-to-one correlation are indicated as solid red and dotted black lines, respectively.