Method evidence record

Measure of Textual Lexical Diversity (MTLD)

The Measure of Textual Lexical Diversity (MTLD) is a length-robust index of vocabulary richness introduced by Philip McCarthy in 2005 and validated by McCarthy and Jarvis in 2010. Rather than computing a single ratio over the whole text, MTLD reads the text word by word, tracking a running type-token ratio, and counts how many sequential word runs are needed before the ratio repeatedly falls to a criterion value of 0.720. The mean length of those runs, computed forward and backward and averaged, is the MTLD score — and in validation studies it was the one common index that did not vary systematically with text length.

Evidence statusSources recorded, not reviewedBibliographic sources are present. Claim-level evidence review has not been performed.

Source record

Recorded

Citations copied verbatim from the method’s source record. No claim-level verification is inferred from them.

Curated claims

Assessed

Claims persisted in the evidence ledger, each with its own assessment.

No curated claims yet

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Related methods

Suggested4

Generated from the method graph and shown as machine-suggested relations. No evidence claim is inferred.