StrømnesF. J. The straight serial curve in anticipation. Evidence for a new invariance.Scand. J. Psychol., 1972,13, 43–53.—The bow‐shaped serial curve in anticipation learning is usually generated by using counterbalancing techniques. Numerous curves in the literature testify that serial curves from experiments without counterbalancing are often very irregular in appearance. Plotting such curves as well as the classical bow‐shaped ones by proportions of errors and omissions as a function of order of learning, the curves can be shown to be straight ascending ones. On the average subjects thus learn a series of verbal items at a constant rate, irrespective of the experimenter‐determined order of