Original sentence: The experience of "learning curves" was first observed by the 19th Century German psychologist Hermann Ebbinghaus according to the difficulty of memorizing varying numbers of verbal stimuli, and subsequent learning about the complex processes of learning are discussed in the
Edited sentence: Subsequent learning about the complex processes of learning are discussed in the Learning curve article.The experience of "learning curves" was first observed by the 19th Century German psychologist Hermann Ebbinghaus according to the difficulty of memorizing varying numbers of verbal stimuli