The paper evaluates whether text-davinci-003 can classify Big Five traits zero-shot from 20 Facebook posts per person. It starts with 202 US participants who consented to share posts and complete a psychological battery; requiring exactly 20 posts from the final year leaves 142 people with continuous Big Five scores from 1 to 5. The authors turn those scores into two or three classes using quantiles and compare four prompts: a basic prompt and three variants adding a textbook definition, correlated word lists, or two questionnaire items. The trivial baseline predicts the most frequent class (MFC), while the strong comparator is WT-LEX, a supervised ridge regression over n-grams and LDA topics previously trained on Facebook data. In binary classification, GPT-3 obtains mean macro-F1 of 0.400 with the basic prompt, 0.419 with a definition, 0.441 with word lists, and 0.454 with questionnaire items; MFC reaches 0.379 and WT-LEX 0.518. GPT-3’s best prompt exceeds WT-LEX on conscientiousness (0.521 versus 0.393) and extraversion (0.569 versus 0.516), but trails it on openness, agreeableness, and neuroticism. Moving from two to three classes lowers the item-prompt mean macro-F1 from 0.454 to 0.230, close to the three-class MFC reported as 0.212; this supports the paper’s explicit conclusion that the model is unsuitable for fine-grained or continuous estimation. Changing the item pairs yields averages from 0.430 to 0.454, with no stable advantage for one formulation. The LIWC analysis suggests that GPT-3 handles social language for extraversion better, but misses associations between social/affective language and openness. The evidence concerns one closed model snapshot, a small sample, and classification relative to this dataset; it does not validate individual psychometric assessment or clinical use. Inspection of the public repository confirms the prompts and text-davinci-003 calls but does not support complete reproduction: data, predictions, metric code, the baseline, statistical analyses, and a runnable configuration are absent; the PDF also sets frequency_penalty to 0.1 while the public code sets it to 0.0.
Research question
What knowledge about traits improves zero-shot personality estimation with GPT-3, how does it compare with a supervised lexical model, how much does it worsen as granularity increases, and does it maintain its predictions when external prompt items are changed?