Keywords
Pillai-score reliability, merger underreporting, data-size effects
Abstract
Pillai Scores
Are they good measures?
- Often supported in meta-analyses (Nycz & Hall-Lew 2013, Kelley & Tucker 2020)
- Appear to be better than Euclidean distance, mixed-effects regression, spectral overlap, SOAM, VOACH, APP, etc.
- However, Bhattacharyya’s Affinity may be better suited for vowel data since it’s robust to skewed data. (Johnson 2015)
Implications:
Mergers are probably underreported and separation is probably overreported
- It takes a lot of data (more than many studies use) to get reliably low Pillai scores
- Mergers may be more common previously reported
Statistical significance should be reported
-
Reporting p -values from MANOVA tests removes the need for ad hoc thresholds. puts less weight on Pillai scores, and makes interpretation more objective.
Comparison across studies
- Analyses of speakers with less data will look less merged
- Analysis of speakers with more data will look more merged
Comparison within studies
- Speakers with less data will have inflated Pillai scores.
- Reading tasks will have higher scores than conversational data (which will be interpreted as style differences)
Original Publication Citation
Joseph A. Stanley & Betsy Sneller. “Sample size matters when calculating Pillai scores.” Poster presentation at the 181st Meeting of the Acoustical Society of America (ASA). Seattle, WA. November 29, 2021
BYU ScholarsArchive Citation
Stanley, Joseph A. and Sneller, Betsy, "Sample Size Matters When Calculating Pillai Scores" (2021). Faculty Publications. 7998.
https://scholarsarchive.byu.edu/facpub/7998
Document Type
Poster
Publication Date
2021
Publisher
181st Meeting of the Acoustical Society of America
Language
English
College
Humanities
Department
Linguistics
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