2011 Reprint of 1913 Edition. Full facsimile of the original edition, not reproduced with Optical Recognition Software. Hermann Ebbinghaus (1850-1909) was a German psychologist who pioneered the experimental study of memory, and is known for his discovery of the forgetting curve and the spacing effect. He was also the first person to describe the learning curve. In 1885, he published his groundbreaking Uber das Gedachtnis ("On Memory," later translated to English as "Memory: A Contribution to Experimental Psychology") in which he described experiments he conducted on himself to describe the processes of learning and forgetting. Ebbinghaus made several findings that are still relevant and supported to this day. First, arguably his most famous finding, the forgetting curve. The forgetting curve describes the exponential curve that illustrates how fast we tend to forget the information we had learned. The sharpest decline is in the first twenty minutes, then in the first hour, and then the curve evens off after about one day.