**Algorithm characterizations** are attempts to formalize the word algorithm. Algorithm does not have a generally accepted formal definition. Researchers are actively working on this problem. This article will present some of the "characterizations" of the notion of "algorithm" in more detail.

*This article is a supplement to the article Algorithm.*

Read more about Algorithm Characterizations: The Problem of Definition, Chomsky Hierarchy, 1881 John Venn's Negative Reaction To W. Stanley Jevons's Logical Machine of 1870, 1943, 1952 Stephen Kleene's Characterization, 1954 A. A. Markov's Characterization, 1936, 1963, 1964 Gödel's Characterization, 1967 Minsky's Characterization, 1967 Rogers' Characterization, 1968, 1973 Knuth's Characterization, 1972 Stone's Characterization, 1995 Soare's Characterization, 2000 Berlinski's Characterization, 2000, 2002 Gurevich's Characterization, 2003 Blass and Gurevich's Characterization, 1995 – Daniel Dennett: Evolution As An Algorithmic Process, 2002 John Searle Adds A Clarifying Caveat To Dennett's Characterization, 2002: Boolos-Burgess-Jeffrey Specification of Turing Machine Calculation, 2006: Sipser's Assertion and His Three Levels of Description