A Contribution to Experimental Psychology, published in 1913. In it, Ebbinghaus outlines his methodology for studying memory, based on the principles of scientific experimentation and quantitative measurement . He criticizes traditional methods of memory research, considering them insufficiently precise and objective. Ebbinghaus proposes the use of nonsense syllables as a new tool that allows eliminating the influence of meaning on the results of the experiment. The book also describes Ebbinghaus's experiments , which demonstrate the dependence of memorization on the number of repetitions , time , and order of words in a series, as well as the principles of association of ideas . Overall, Ebbinghaus's text represents an important contribution to the development of experimental psychology , paving the way for modern memory research.