SHRDLU
In plain wordsA program from around 1970 that let people move toy blocks in a simulated world by typing ordinary English commands and questions, and that could explain what it had done and why.
A natural-language understanding system built by Terry Winograd at the MIT AI Laboratory in 1968–1970. Users conversed in English with a simulated robot arm that moved colored blocks, pyramids and boxes on a table — a so-called blocks world. SHRDLU parsed commands and questions with a procedural grammar, resolved pronouns and references from the dialogue history and the state of the scene, planned multistep actions (clearing a block before moving it), accepted new names for objects and answered questions about its past actions and their reasons. Its integration of syntax, meaning, reasoning and planning made it one of the most admired demonstrations of early symbolic AIsymbolic AI, n.: An approach to AI that writes knowledge down as human-readable symbols and rules, such as 'every bird has wings', and reasons by manipulating them step by step instead of learning patterns from data.. Its methods did not carry over to open-ended domains, and it became the standard example of a microworld, a deliberately simplified domain whose methods failed to scale.
SHRDLU could say why it had picked up a block, but only inside its tabletop world.
Origin
Described in Winograd's 1971 MIT doctoral thesis and his 1972 book Understanding Natural Language. The name comes from 'ETAOIN SHRDLU', the approximate letter-frequency order of keys on Linotype typesetting machines, which sometimes appeared in newspapers as a filler error.
Usage note
Winograd later criticized the symbolic approach in Understanding Computers and Cognition (1986, with Fernando Flores). An ambiguous-pronoun example from his 1972 work inspired the Winograd schema challengeWinograd schema challenge, prop. n.: A test of machine common sense built from pairs of sentences in which changing one word changes what a pronoun refers to — something people resolve instantly using everyday knowledge..
Related
- symbolic AIsymbolic AI, n.: An approach to AI that writes knowledge down as human-readable symbols and rules, such as 'every bird has wings', and reasons by manipulating them step by step instead of learning patterns from data.
- good old-fashioned AIgood old-fashioned AI, n.: A nickname for the classic style of AI, dominant from the 1950s to the 1980s, that tried to make computers intelligent by writing knowledge and rules down by hand.
- natural language understandingnatural language understanding, n.: The part of language AI concerned with working out what a piece of text means — who did what to whom, what the writer wants and what follows from it — rather than with producing text.
- automated planningautomated planning, n.: The branch of AI that works out a sequence of actions to reach a goal, such as the steps a robot must take to assemble a part, from descriptions of what each action needs and what it changes.
- ELIZAELIZA, prop. n.: A 1960s computer program that chatted by turning a user's own words back into questions, like a therapist. Many users felt understood, though the program understood nothing.
- Winograd schema challengeWinograd schema challenge, prop. n.: A test of machine common sense built from pairs of sentences in which changing one word changes what a pronoun refers to — something people resolve instantly using everyday knowledge.
Sources
- Winograd, T. (1972). Understanding Natural Language. New York: Academic Press.
Mentioned in
ELIZAELIZA, prop. n.: A 1960s computer program that chatted by turning a user's own words back into questions, like a therapist. Many users felt understood, though the program understood nothing., good old-fashioned AIgood old-fashioned AI, n.: A nickname for the classic style of AI, dominant from the 1950s to the 1980s, that tried to make computers intelligent by writing knowledge and rules down by hand., LispLisp, prop. n.: A programming language invented in 1958 for AI research, in which programs and data are written the same way, as nested lists in parentheses. It was the main language of AI for decades., natural language understandingnatural language understanding, n.: The part of language AI concerned with working out what a piece of text means — who did what to whom, what the writer wants and what follows from it — rather than with producing text., blocks worldblocks world, n.: A simplified pretend world of toy blocks on a table that early AI researchers used to test programs for planning, seeing and understanding language, because it was simple enough to describe completely., microworldmicroworld, n.: A small, deliberately simplified artificial setting, such as a table of toy blocks, in which an AI program can be tested in full detail before anyone tries it in the messy real world., MIT AI LabMIT AI Lab, prop. n.: The artificial intelligence laboratory at the Massachusetts Institute of Technology, founded in 1959 and one of the birthplaces of AI and hacker culture; it is now part of MIT's computer science lab, CSAIL., Terry WinogradTerry Winograd, prop. n.: An American computer scientist who built SHRDLU, a celebrated early program that conversed in English about a world of blocks, and later became a critic of symbolic AI., Winograd schema challengeWinograd schema challenge, prop. n.: A test of machine common sense built from pairs of sentences in which changing one word changes what a pronoun refers to — something people resolve instantly using everyday knowledge.