A Bayesian approach to uncertainty in word embedding bias estimation
Alicja Dobrzeniecka Rafal Urbaniak
Multiple measures, such as WEAT or MAC, attempt to quantify the magnitude of
bias present in word embeddings in terms of a single-number metric. However,
such metrics and the related statistical significance calculations rely on
treating pre-averaged data as individual data points and employing
bootstrapping techniques with low sample sizes. We show that similar results
can be easily obtained using such methods even if the data are generated by a
null model lacking the intended bias. Consequently, we argue that this approach
generates false confidence. To address this issue, we propose a Bayesian
alternative: hierarchical Bayesian modeling, which enables a more
uncertainty-sensitive inspection of bias in word embeddings at different levels
of granularity. To showcase our method, we apply it to Religion, Gender, and
Race word lists from the original research, together with our control neutral
word lists. We deploy the method using Google, Glove, and Reddit embeddings.
Further, we utilize our approach to evaluate a debiasing technique applied to
Reddit word embedding. Our findings reveal a more complex landscape than
suggested by the proponents of single-number metrics. The datasets and source
code for the paper are publicly available.