Cheder metukan ("improved cheder", sometimes interpreted as "revised cheder", "progressive cheder" or "reformed cheder" and sometimes transliterated as cheder methukan) was a type of elementary education schools for young Jewish children introduced by the Zionist movement at the break of the 19th and 20th centuries in the Russian Empire (which at that time incorporated considerable parts of Poland and Lithuania) to address the problems of the outdated and inefficient system of traditional cheders. The curricula of the cheder metukan differed depending on the organizer, but the major distinctive features were introduction of the elements of secular education (such as history of the Jews and geography of Eretz Yisrael), / "Ivrit veIvrit" way of teaching (using Hebrew as the sole medium of teaching), and education for girls. The conservative circles saw this as a threat to their status in the system of education and in the Jewish society, and ardently opposed the introduction of these schools.
This method was based on the following principle:
Opponents angrily quipped that they were not cheder mehtukan (), but cheder mesukan (, "dangerous cheder").
In the autobiography, Chaim Weizmann described the situation as follows: