REVIEW 3 major objections 5 minor 1 cited by
PolitiSky24: U.S. Political Bluesky Dataset with User Stance Labels
T0 review · 3 major / 5 minor · reviewed 2026-08-07 · deepseek-v4-flash
Pith's one-line read PolitiSky24 gives researchers the first user-level stance labels for the 2024 U.S. election from Bluesky.
desk verdict Useful first Bluesky user-stance resource, but the 81% accuracy is measured on a hashtag-sampled validation set and should be treated as an upper bound on full-dataset label quality. read the letter →
The pith
A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.
The reading
What carries the argument
The load-bearing mechanism is a two-stage label pipeline. In stage one, a stance-based document retriever (KaLM-mini-v1.5, chosen by comparing embedding models on a 700-query relevance set) selects the top posts for and against each target from a user's history; in stage two, an LLM (DeepSeek-Chat-v3, chosen by comparing LLMs on a 446-user human-labeled set) reads those posts and outputs Favor, Against, or Neither, plus the reasoning and the specific spans that support it. The validation set itself is the second mechanism: users are selected by hashtags such as #NeverTrump and #FireKamala, so the accuracy estimate is anchored to users who make their stances explicit.
What would settle it
Sample a set of users who never used any stance-indicative hashtag, have three annotators label their stances under the paper's own guidelines, and run the pipeline on them; if agreement drops well below 81%, the reported accuracy does not transfer to the full dataset.
Extended reading notes
Core claim
The central claim is that user-level stance can be assigned reliably at scale by combining a stance-aware retriever with a large language model. Using 8,467 users and about 2.85 million English posts collected from political feeds, the pipeline first retrieves the ten most stance-relevant posts for each user-target pair with an embedding model, then prompts DeepSeek-Chat-v3 to label the user's stance toward Harris and Trump with a rationale. On 446 hashtag-sampled users whose stances were independently labeled by human experts, the model reaches 81.2% overall accuracy, with macro F1 of 66.2% for Trump and 72.6% for Harris. The paper also documents where the model fails: most errors come from faulty reasoning, genuinely ambiguous posts, and insufficient retrieved context, and the largest class-level confusion is labeling 'Neither' users as 'Favor' when they neutrally report positive content. The released dataset of 16,044 user-target stance pairs is presented as the first such resource for the 2024 election and as an open, explainable basis for studying political alignment on Bluesky.
Load-bearing premise
The 81.2% accuracy measured on validation users who deliberately used stance hashtags is assumed to hold for all other users, whose labels are produced by the same LLM without human checking.
Editorial extensions
If this is right
- Researchers can study political stance on Bluesky at user level, using labels accompanied by rationales and source spans rather than bare classifications.
- The like and repost networks (869,367 and 498,084 edges) make it possible to connect stance labels to community structure and influence.
- The pipeline provides a reusable recipe for building stance datasets on platforms that, unlike Twitter/X, still offer open API access.
- The label distribution—majority Against Trump, majority non-opposed to Harris—quantifies the platform's left-leaning political tilt in the 2024 cycle.
Reading between the lines
- Our inference: because the validation users were selected from users of stance-indicative hashtags, the reported 81.2% accuracy is likely an upper bound for the full dataset, where many users never make their stance explicit.
- Our inference: a direct test of the transfer assumption would be to run the pipeline on hashtag-free users and compare its labels to fresh human annotations; the paper does not report this comparison.
- Our inference: the model's tendency to read neutral positive reporting as support means downstream analyses should interpret labels as expressed stance in the users' posts, not as private voting intention.
- Our inference: because each label carries the LLM's reasoning and quoted spans, the dataset supports post hoc audit and iterative relabeling, so the accuracy could be improved without recollecting data.
Editorial analysis
A structured set of objections, weighed in public.
Referee Report
Summary. This paper presents PolitiSky24, a user-level stance detection dataset for the 2024 U.S. presidential election, collected from Bluesky. The dataset contains 16,044 user-target stance pairs for Kamala Harris and Donald Trump, enriched with engagement metadata, interaction graphs, and user posting histories. The authors propose a two-stage labeling pipeline: first, an embedding model retrieves stance-relevant posts from a user's history; second, a large language model assigns a stance label (Favor, Against, Neither) with supporting rationale and text spans. The pipeline is configured and evaluated on a hashtag-sampled validation set of 446 users, where DeepSeek-Chat-v3 achieves 81.2% overall accuracy. The authors then apply this pipeline to the full dataset of 8,022 users without human verification of the resulting labels. The paper also analyzes error categories, reports stance distributions, and provides the dataset openly.
Significance. If the labeling quality is reliable, PolitiSky24 fills a clear gap: it is, to the authors' knowledge, the first user-level stance dataset for the 2024 U.S. election, and one of the first stance resources from Bluesky. The dataset's richness—posting histories, interaction networks, rationales, and text spans—could support multiple downstream studies in computational social science and NLP. The paper also contributes a systematic comparison of embedding models and LLMs for stance detection, with transparent prompts and error analysis. However, the central claim of high labeling accuracy (81%) is only validated on a non-representative, hashtag-sampled subset, and the full-dataset labels are produced by an LLM without human checks. Because researchers will likely treat these labels as ground truth, the transferability of the validation accuracy to the full dataset is the load-bearing risk. The authors do acknowledge sampling bias in the Limitations section, but they do not quantify its effect on full-dataset label quality.
major comments (3)
- [§4.2.1 and §5.1 (Figure 5)] The reported 81.2% accuracy is computed on a validation set of 446 users sampled via stance-indicative hashtags (Section 4.2.1), but the full dataset comprises 8,022 users who were not subject to any hashtag requirement and whose labels are entirely LLM-generated with no human verification. The paper's own Limitations acknowledges that hashtag users may exhibit 'more extreme or clearly articulated stances,' which makes the validation set easier than the full population. This concern is not merely hypothetical: comparing Table 12 and Table 14, the proportion of Harris 'Neither' labels rises from 39.6% in the human validation set to 52.6% in the full dataset, while the LLM's accuracy on 'Neither' is only 66.8% (Figure 8). The overall accuracy on the full dataset is therefore likely lower than 81.2%. The authors should either provide human-verified labels on a random sample of full-dataset users, or revise the paper's claims to state clearly that 81.2% is a validation-set-specific accuracy and does not necessarily transfer.
- [§4.2.3 and Figure 5] The same validation set is used both to select the best-performing LLM and embedding model and to report the final accuracy. This makes the 81.2% figure a best-of-many estimate on that set, which is optimistically biased. A rigorous evaluation would split the human-annotated data into development and test sets (or use nested resampling) so that model selection and final evaluation are independent. In addition, no majority-class baseline or confidence intervals are reported; given the strong label imbalance in the validation set (e.g., Trump 'Against' constitutes 87.6% of human labels), overall accuracy alone is not an informative metric. The authors should report per-class precision, recall, and F1, and compare against a majority-class baseline.
- [Abstract and §5.1] The abstract and conclusion state that 'the labeling approach achieves 81% accuracy' without the crucial caveat that this accuracy is measured only on the hashtag-sampled validation set, while the labels in the released dataset are entirely LLM-generated and unverified. This overstates the reliability of the resource. If the authors cannot obtain a representative human-annotated sample, they should at least present the accuracy as an upper bound and explicitly warn downstream users about the potential distribution shift between the validation set and the full dataset, as exemplified by the Harris 'Neither' discrepancy.
minor comments (5)
- [§4.2.2] The text says 350 post–target entity pairs were annotated, leading to 4 × 175 = 700 query–stance relevance pairs, but the relationship between 350 and 175 is not explained; please clarify how the 175 pairs are derived from the 350 post–target pairs.
- [Table 3] The hashtag '#V oteHarrisWalz202' appears to contain a space; this is likely a typo for '#VoteHarrisWalz202'.
- [§5.1] The model name 'LLAMA-3.3-70B-Instruct' should be written as 'Llama-3.3-70B-Instruct' for consistency with the cited technical report.
- [Table 12 and Figure 5] The denominator used to compute the 81.2% accuracy is not explicit; the table reports counts of 'Common Users' for each target, but it is unclear whether accuracy is averaged over both targets or computed on the union of user–target pairs. Please state this precisely.
- [§5.2] The phrase 'most users do not express opposition toward Harris' is vague; consider reporting the exact percentages from the full dataset distribution rather than qualitative statements, since the dataset's own distribution is central to the paper's findings.
Circularity Check
No significant circularity: accuracy is measured against independent expert labels; remaining caveats are evaluation-bias concerns, not derivation circularity.
full rationale
PolitiSky24's core claim—that the retrieval-plus-LLM labeling pipeline reaches 81% accuracy—is supported by a comparison of LLM predictions to human expert labels on a held-out validation set (Sections 4.2.3 and 5.1, Figure 5). The human labels are external to the pipeline, so the accuracy is a measured agreement, not a quantity defined by the pipeline's own outputs. The later full-dataset labels are generated by the same pipeline without human verification, and the validation set was hashtag-sampled; the paper's Limitations acknowledges that this may bias toward users with more extreme or clearly articulated stances. Additionally, the same validation set is used both to select the best embedding model and LLM and to report the final accuracy, which makes 81.2% a selection-optimized, in-sample estimate rather than an unbiased forecast for the full dataset. These are important evaluation and generalizability caveats, but they are not circular derivation: no step reduces by construction to its inputs, no load-bearing self-citation is used, and the pipeline is grounded in independent human annotations. Accordingly, no circularity steps are identified.
Assumptions & free parameters
free parameters (5)
- Minimum posts threshold for target user inclusion (10 posts/reposts) =
10
- Context posts per user-target pair (top 5 stance-relevant support + top 5 against = 10 posts) =
10 (5+5)
- Maximum recent English posts retrieved per user =
1,000
- Validation set size as 5% hashtag-sampled users =
446 users
- Feed collection window =
Nov 12-27, 2024 (16 days)
assumptions (5)
- domain assumption Users who use stance-indicative hashtags are a valid proxy for identifying validation users with known stances.
- domain assumption The three selected Bluesky feeds represent U.S. political discourse on Bluesky.
- domain assumption LLM-generated stance labels on the full dataset are treated as ground-truth user stances without human verification.
- domain assumption Human expert labels on the validation set are reliable.
- domain assumption Embedding retrieval precision at top k is sufficient to provide the LLM with stance-relevant context.
Cite this review
Pith. "Pith review of PolitiSky24: U.S. Political Bluesky Dataset with User Stance Labels." pith.science (2026). https://pith.science/paper/EPKZUJ77
@misc{pith2026250607606,
author = {Pith},
title = {Pith review of: PolitiSky24: U.S. Political Bluesky Dataset with User Stance Labels},
year = {2026},
howpublished = {\url{https://pith.science/paper/EPKZUJ77}},
note = {Machine review of arXiv:2506.07606}
}
read the original abstract
Stance detection identifies the viewpoint expressed in text toward a specific target, such as a political figure. While previous datasets have focused primarily on tweet-level stances from established platforms, user-level stance resources, especially on emerging platforms like Bluesky remain scarce. User-level stance detection provides a more holistic view by considering a user's complete posting history rather than isolated posts. We present the first stance detection dataset for the 2024 U.S. presidential election, collected from Bluesky and centered on Kamala Harris and Donald Trump. The dataset comprises 16,044 user-target stance pairs enriched with engagement metadata, interaction graphs, and user posting histories. PolitiSky24 was created using a carefully evaluated pipeline combining advanced information retrieval and large language models, which generates stance labels with supporting rationales and text spans for transparency. The labeling approach achieves 81\% accuracy with scalable LLMs. This resource addresses gaps in political stance analysis through its timeliness, open-data nature, and user-level perspective. The dataset is available at https://doi.org/10.5281/zenodo.15616911
Figures
Figures from the paper (8 more)
Forward citations
Cited by 1 Pith paper
-
Quantifying Political Partisanship for Cross-Platform Analyses
Partisanship of individual posts can be scored on a common embedding axis anchored by AllSides news-bias labels, yielding cross-platform scores that transfer from Bluesky/Truth Social to X.
Reference graph
Works this paper leans on
-
[3]
In Proceedings of the 2024 ACM on Internet Measurement Conference , pages 76–91, New York, NY , USA
Looking AT the blue skies of bluesky. In Proceedings of the 2024 ACM on Internet Measurement Conference , pages 76–91, New York, NY , USA. ACM. Costanza Conforti, Jakob Berndt, Mohammad Taher Pilehvar, Chryssi Giannitsarou, Flavio Toxvaerd, and Nigel Collier
work page 2024
-
[4]
arXiv preprint arXiv:2407.21783
The llama 3 herd of models. arXiv preprint arXiv:2407.21783. Andrea Failla and Giulio Rossetti
-
[7]
Bluesky and the AT protocol: Usable decentralized social media. In Proceedings of the ACM Conext-2024 Workshop on the Decentralization of the Internet , pages 1–7, New York, NY , USA. ACM. Yingjie Li, Tiberiu Sosea, Aditya Sawant, Ajith Ja- yaraman Nair, Diana Inkpen, and Cornelia Caragea. 2021a. P-stance: A large dataset for stance detection in political...
work page 2024
-
[8]
arXiv preprint arXiv:2412.19437
Deepseek-v3 technical report. arXiv preprint arXiv:2412.19437. Saif Mohammad, Svetlana Kiritchenko, Parinaz Sob- hani, Xiaodan Zhu, and Colin Cherry
-
[9]
Bluesky: Network Topology, Polarization, and Algorithmic Curation
Bluesky: Network topology, polarisation, and algorithmic cu- ration. arXiv preprint arXiv:2405.17571. Dorian Quelle and Alexandre Bovet
-
[10]
From millions of tweets to actionable insights: Leveraging llms for user profiling. Preprint, arXiv:2505.06184. Majid Zarharan, Maryam Hashemi, Malika Behroozrazegh, Sauleh Eetemadi, Mohammad Taher Pilehvar, and Jennifer Foster
-
[11]
FarExStance: Explainable Stance Detection for Farsi
Farexstance: Explainable stance detection for farsi. arXiv preprint arXiv:2412.14008. Bowen Zhang, Genan Dai, Fuqiang Niu, Nan Yin, Xiao- mao Fan, and Hu Huang
-
[12]
arXiv preprint arXiv:2409.15690
A survey of stance detection on social media: New directions and per- spectives. arXiv preprint arXiv:2409.15690. Chenye Zhao and Cornelia Caragea
Show all 16 references
-
[13]
Politics, aged 26, 27, and 32, who provided specialized knowledge essential for accurate stance labeling
Our annotation process was supported by three male experts in U.S. Politics, aged 26, 27, and 32, who provided specialized knowledge essential for accurate stance labeling. Stance label Description Favor • Directly expressing support for the tar- get entity. • Expressing suppo...
2024
-
[14]
D.1.2 User Post History Users’ post histories are stored using the fields specified in Table 6, which lists each field along with its valid values and detailed descriptions
In total, 8,561 unique users—each with at least 10 posts across these three feeds—were included in our dataset. D.1.2 User Post History Users’ post histories are stored using the fields specified in Table 6, which lists each field along with its valid values and detailed descr...
2024
-
[15]
Table 12 reports statistics on the number of users labeled by humans, the LLM, and both, categorized by stance and target
D.2.2 User Stance (Validation dataset) Table 11 presents the schema of the validation user stance dataset. Table 12 reports statistics on the number of users labeled by humans, the LLM, and both, categorized by stance and target. Figure 13 shows the distribution of labels to- ...
2024
-
[16]
Additionally, Table 14 provides statistics on the context posts and LLM- generated fields across the entire dataset
This table details all dataset fields, including their possible values and descriptions. Additionally, Table 14 provides statistics on the context posts and LLM- generated fields across the entire dataset. E LLM Usage Statement We acknowledge the use of Large Language Mod- els...
2022
-
[2020]
In Proceedings of the 2020 Conference on Empirical Methods in Natural Language Processing (EMNLP), pages 8913– 8931, Online
Zero- Shot Stance Detection: A Dataset and Model using Generalized Topic Representations. In Proceedings of the 2020 Conference on Empirical Methods in Natural Language Processing (EMNLP), pages 8913– 8931, Online. Association for Computational Lin- guistics. Sunil Arya, David...
2020
-
[2021]
In Proceedings of the 2021 Con- ference of the North American Chapter of the Asso- ciation for Computational Linguistics: Human Lan- guage Technologies, pages 4725–4735, Online
Knowledge enhanced masked language model for stance detection. In Proceedings of the 2021 Con- ference of the North American Chapter of the Asso- ciation for Computational Linguistics: Human Lan- guage Technologies, pages 4725–4735, Online. As- sociation for Computational Ling...
2021
-
[2024]
arXiv preprint arXiv:2412.08905
Phi-4 technical re- port. arXiv preprint arXiv:2412.08905. Emily Allaway and Kathleen McKeown
-
[2025]
arXiv preprint arXiv:2501.01028
Kalm- embedding: Superior training data brings a stronger embedding model. arXiv preprint arXiv:2501.01028. Ujun Jeong, Bohan Jiang, Zhen Tan, H Russell Bernard, and Huan Liu
Reviewed August 7, 2026 · model on record in the stance chip above.
Discussion (0). Sign in to comment.