From a 1917 journal published by the Moscow Art Theatre (MAT):

“Chekhov wrote Three Sisters in Yalta, and then rewrote it in early autumn in Moscow. He spent two to three days on each act, but there were significant breaks between the acts. 

With complete sincerity he said that he had written a vaudeville, and was taken aback at our amusement of this definition of Three Sisters…

Chekhov was present for the first read-through of the play by the actors. As on another occasion when the actors plied him with questions about particular aspects of their parts which seemed unclear to them, Chekhov not only refused any lengthy explanations, but rather categorically answered them with short, monosyllabic words… 

Given the ensemble playing, the friendliness of the performance, and maturity of form, Three Sisters was always seen in the theatre as the best of the Chekhov productions.”

These words were written by Nemirovich-Danchenko who
co-founded the MAT with Stanislavski. 

Once the teacher and lover of Olga Knipper, he was the one who championed Chekhov’s plays in the 1890s; returning to the MAT in 1900 to help produce their production of Three Sisters.