Picardy Indexing

QuidiVidi

QuidiVidi is a non-indexing side project of Picardy Indexing. It is used to analyze linguistic transcripts encoded in CHAT format.

You can use QuidiVidi to calculate:

  • MLU (mean length of utterance), MLT, MLU5
  • Word/morpheme frequencies
  • Brown’s morphemes counts
  • Lexical class percentages (nouns, verbs, etc.)
  • Maximum length of words/utterances
  • Comparisons between tokens on different CHAT tiers
  • Distribution of words, utterances, and turns of various lengths
  • Lexical diversity

You can also filter the input on tier-specific search terms.

QuidiVidi is available for Windows™, Macintosh™, and Linux. These should be considered alpha software since more testing may be carried out and features may be added and/or modified. Your feedback is welcomed (picardy.indexing@gmail.com)!

Terms and conditions

QuidiVidi is free of charge and freely distributable. The source code will not be made available. QuidiVidi is licensed under Creative Commons Attribution 4.0 International. To view a copy of this license, visit https://creativecommons.org/licenses/by/4.0/ (I’m not a lawyer, but my interpretation of the license is that, basically, you don’t have to pay me anything to download and use the software, and I can’t be held liable if the software doesn’t work the way you expect. Furthermore, you can redistribute and/or repackage the software into a product of your own but you need to give me credit.)

Downloads

Click below to download an installer for the appropriate platform.

Windows (MSI; 44MB; uploaded January 18, 2026)

Linux (tar.gz; 73MB; uploaded January 18, 2026)

Macintosh (.zip; 35MB; uploaded January 17, 2026)

Note forMacintosh and Linux users: QuidiVidi toolbar buttons use the Segoe MDL2 Assets font; Windows has this font installed by default, but for Macintosh and Linux you will need to install it before using the software. You can download this font from Microsoft here. Look here if you need instructions for installing fonts in Linux.

Note for Macintosh users: QuidiVidi is not a notarized Apple app, so MacOS will try to tell you that it’s very bad, no good, etc. Pay it no mind. Ctrl-click the app and then click Open; click Open Anyway when prompted. Alternatively you can go to System Settings > Privacy and Security to find the same prompt. Happy sailing!