The concept of effective dose was introduced in 1975 by Wolfgang Jacobi (1928–2015) in his publication "The concept of an effective dose: a proposal for the combination of organ doses". It was quickly included in 1977 as “effective dose equivalent” into Publication 26 by the ICRP. In 1991, ICRP publication 60 shortened the name to "effective dose." This quantity is sometimes incorrectly referred to as the "dose equivalent" because of the earlier name, and that misnomer in turn causes confusion with equivalent dose. The tissue weighting factors were revised in 1990 and 2007 due to new data.