Analysis of the mean performance of 58 groups of normal adults and children on the free-recall trials of the Rey Auditory-Verbal Learning Test shows that the mean auditory-verbal learning of each group is described by the function R1+ Sln (t), where R1 is a measure of the mean immediate memory span, S is the slope of the mean logarithmic learning curve, and ln (t) is the natural logarithm of the trial number t. The analysis also shows that R1 varies with age and other demographic factors, whereas S is almost a constant, and it yields equations for estimating the effect of these factors on R1. Potential use of these findings for assessment of auditory-verbal memory and learning in comparative clinical studies is discussed.