science

PARRY

PARRY is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand PARRY rather than just read about it. In short: PARRY was an early example of a chatbot, implemented in 1972 by psychiatrist Kenneth Colby. History PARRY was written in 1972 by psychiatrist Kenneth Colby, then at Stanford University.

Key takeaways

PARRY belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect PARRY to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of PARRY from memory before moving on to harder problems.

Reference excerpt

PARRY was an early example of a chatbot, implemented in 1972 by psychiatrist Kenneth Colby.

History PARRY was written in 1972 by psychiatrist Kenneth Colby, then at Stanford University. While ELIZA was a simulation of a Rogerian therapist, PARRY attempted to simulate a person with paranoid schizophrenia. The program implemented a crude model of the behavior of a person with paranoid schizophrenia based on concepts, conceptualizations, and beliefs (judgements about conceptualizations: accept, reject, neutral). It also embodied a conversational strategy, and as such was a much more serious and advanced program than ELIZA. It was described as "ELIZA with attitude". PARRY was tested in the early 1970s using a variation of the Turing Test. A group of experienced psychiatrists analysed a combination of real patients and computers running PARRY through teleprinters. Another group of 33 psychiatrists were shown transcripts of the conversations. The two groups were then asked to identify which of the "patients" were human and which were computer programs. The psychiatrists were able to make the correct identification only 48 percent of the time — a figure consistent with random guessing. PARRY and ELIZA (also known as "the Doctor") interacted several times. The most famous of these exchanges occurred at the ICCC 1972, where PARRY and ELIZA were hooked up over ARPANET and responded to each other.

See also History of natural language processing

Notes and references

Sources Boden, Margaret A. (2006), Mind As Machine: A History of Cognitive Science, Oxford University Press, ISBN 978-0-19-924144-6 Colby, K. M.; Hilf, F. D.; Weber, S.; Kraemer, H. (1972), "Turing-like indistinguishability tests for the validation of a computer simulation of paranoid processes", Artificial Intelligence, 3: 199–221, doi:10.1016/0004-3702(72)90049-5

External links Parry's Source Code The original LISP code for Parry.

Worked examples

Example 1 — a first encounter with PARRY

Start with the simplest possible case. Write down what PARRY claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to PARRY before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about PARRY ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of PARRY

In research: PARRY appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses PARRY in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: PARRY is common in secondary-school and first-year university syllabi. It links to neighbouring topics Chatbots, History of artificial intelligence, Schizophrenia, so understanding it makes those chapters shorter.
In everyday life: Look for PARRY outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study PARRY in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what PARRY means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain PARRY out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is PARRY in simple terms?

PARRY was an early example of a chatbot, implemented in 1972 by psychiatrist Kenneth Colby. History PARRY was written in 1972 by psychiatrist Kenneth Colby, then at Stanford University.

Why does PARRY matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study PARRY?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on PARRY.