Thorndike CAVD Intelligence Scale (1925)

THE MEASUREMENT OF INTELLIGENCE · 1927Thorndike, Bregman, Cobb, Woodyard, and the staff of the Division of Psychology, Institute of Educational Research, Teachers Collegexxvi + 616 pages [2]

Spearman reviewed it for Nature in October 1927. He noted the investigation was large enough to get a special Carnegie Corporation grant, and that Thorndike had given it the previous four years [3]. The Wellcome Collection's copy is signed by Spearman [2].The book argues that ordinary scores can't be added, subtracted or compared as ratios the way heights and weights can. For rigorous measurement, it says, level, extent and speed should be treated separately [1].This page used to date the scale to 1925. The book is 1927, and the work behind it ran over the years before.

Altitude, width and area

The scale ran in lettered levels, each a composite of the four task kinds. The book's tables convert "any number correct from 5 to 35 out of 40" into an altitude for levels I to Q, with provisional values for A to H [1]. Altitude is how hard the tasks a person can do are; width is how many tasks at a given level; area combines the two [4]. Pick a profile.

IJKLMNOPQ

Number correct out of 40 at each level. Dashed line: 20 of 40. Profiles invented for illustration.

ALTITUDELevel MHighest level with at least 20 of 40 right (our simple rule)

WIDTH5 levelsLevels passed at the 20-of-40 mark

AREA205 tasksTotal right across all levels

A smooth decline: the shape Thorndike's composite levels were built to place.

THE "D" IN CAVD

Read the directions. Then do exactly that.

On paper, Direction-following meant reading a complex written instruction and carrying it out. Here you click the shapes in the order the directions require. Four sets, each more tangled.

Directions written for this page — not Thorndike's items.

SET 1 · 1 CLICK(S)

Click the red square.

123456

Click shapes in the required order.

References

[1]Thorndike, E. L., Bregman, E. O., Cobb, M. V., Woodyard, E., et al. (1927). The Measurement of Intelligence. New York: Bureau of Publications, Teachers College. Text via vdoc.pub; scan on the Internet Archive (University of Toronto).vdoc.pub

[2]The measurement of intelligence / by Edward L. Thorndike [and others] (1927), xxvi + 616 pp. Copy signed by C. Spearman. Wellcome Collection.wellcomecollection.org

[3]Spearman, C. (1927). The Measurement of Intelligence [review]. Nature 120: 577–578.nature.com

[4]Edward L. Thorndike: founder of mental measurement. Cogn-IQ history notes (summarising the 1927 book and Holzinger 1931).cogn-iq.org

[5]Test collection, Box 47: The I.E.R. Intelligence Scale CAVD, Forms 3 and 4, 1946, Levels M–Q. Cornell University Library archives.archives.library.cornell.edu

HOW TO CITE THIS PAGE

What's Your IQ. (2026). Thorndike CAVD Intelligence Scale (1927). In Historical IQ Tests Archive. Retrieved October 1, 2026, from /en/historical-iq-tests/thorndike-cavd-1925

EDITORIAL RECORD

First published2026

Last reviewed1 October 2026

Sources5: the 1927 book (text), a library record, Spearman's Nature review, a history summary and a test-collection listing

CorrectionsDated to 1927 instead of 1925. Removed: "connectionist theory made testable" as the scale's stated aim, the three-way Spearman / Thorndike / Thurstone panel, "less adopted than Otis or the NIT", "highly influential in academic psychometrics", "Trabue as the C in CAVD", and a "Teachers College Press" publisher line.

Open questionsThe exact make-up of each composite level; how the provisional A–H altitudes were set; how widely the scale was used outside research

Canonical URLwhats-your-iq.com/en/historical-iq-tests/thorndike-cavd-1925

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Part of the Historical IQ Tests Archive. Editorial content under CC BY-SA 4.0. The Measurement of Intelligence can be read on the Internet Archive. No CAVD items are reproduced here.

BibTeX RIS

Thorndike CAVD: a scale with equal units and a true zero

Altitude, width and area

Read the directions. Then do exactly that.

References

Related historical tests

One g or many parts? See your own profile.