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Knowledge in the age of AI

Which sources do AI systems surface, how do they attribute knowledge, and what do they overlook?

A review of six published studies on how AI assistants cite their sources, followed by a method for a study Project 3rd Rock has not yet run. Each figure links to the study it came from.

Summary

What the evidence says so far

Across the studies reviewed, AI assistants get their sources wrong often enough that a citation cannot be taken on trust, and few readers check. The studies cover news and one restoration domain. None asked climate or sustainability questions across languages, which is the gap the proposed method is written for.

  • Asked to identify the article behind a news excerpt, eight AI search tools answered more than 60 percent of 1,600 requests incorrectly. Perplexity was wrong 37 percent of the time and Grok 3 94 percent.

    Columbia Journalism Review, Tow Center, March 2025

  • In an audit of four generative search engines, about half of generated sentences were fully supported by their citations, and about three in four citations supported the sentence they sat beside.

    Liu, Zhang and Liang, April 2023

  • When Google showed an AI summary, about 1 percent of visits included a click on a link inside it. Clicks on ordinary results fell from 15 percent of visits to 8 percent.

    Pew Research Center, July 2025

  • Asked about ecological restoration, ChatGPT drew on male academics at US universities in over two-thirds of 30,000 answers. Indigenous and community experience appeared in 2 percent.

    Urzedo and colleagues, 2024

  • Across six chatbots, Hindi news questions scored lowest, and models cited English Wikipedia more often than any Hindi-language outlet.

    Suzgun and colleagues, preprint, May 2026

Why it matters

Answers now arrive before sources

More people meet knowledge as a composed answer than as a list of pages. What the answer cites, and what it leaves out, shapes which institutions, places and languages are visible. For climate and sustainability work, where practical knowledge is often local, multilingual and held outside the largest publishers, the question is not only whether an answer is correct. It is whose knowledge was available to be found.

What existing evidence says

Six studies, read side by side

Three of the studies produced figures that can be drawn. They differ in task, date, systems and language, so the numbers do not sit on one scale. Each chart names its source and what it cannot show.

Fig. 01

Answers to a citation task that were wrong or misattributed

  • Perplexity37%
  • DeepSeek (misattributed)115 of 200
  • ChatGPT (incorrectly identified)134 of 200
  • Grok 394%

Each tool was shown a news excerpt and asked for headline, publisher, date and URL. Grok 3 is highlighted as the highest reported rate. Perplexity is the lowest.

The measures differ slightly: Perplexity and Grok 3 are percentages stated by the authors. ChatGPT (134 of 200 incorrectly identified) and DeepSeek (115 of 200 misattributed) are counts reported by the authors, converted here to a share of 200. Four of the eight tools tested are shown; the authors did not state rates for the rest. Tests ran in February 2025.

Source: Columbia Journalism Review, Tow Center ↗. Published 6 March 2025. Scale 0 to 100 percent.

Fig. 02

Do the citations support what is written

  • Sentences fully supported by citations (recall)51.5%
  • Citations that support their sentence (precision)74.5%

Averaged across four generative search engines as they stood in early 2023. Fewer than six in ten sentences were fully supported, though most individual citations did support their sentence.

Citation recall asks whether every statement is backed by citations. Citation precision asks whether each citation supports its sentence. The systems audited have since changed, so this shows the shape of the problem, not today's rates.

Source: Liu, Zhang and Liang, arXiv:2304.09848 ↗. Published 19 April 2023. Scale 0 to 100 percent.

Fig. 03

How often readers follow a link

  • Click on a result, page without AI summary15%
  • Click on a result, page with AI summary8%
  • Click on a link inside the AI summaryabout 1%

Share of Google visits, among 900 tracked US adults in March 2025, that included each action. Links inside the AI summary were rarely used.

Browsing logs show behaviour, not intent. Only Google was analysed, and only the first three links cited in each summary were checked.

Source: Pew Research Center ↗. Published 22 July 2025. Scale 0 to 100 percent.

Findings by theme

All six studies follow, grouped by what each one measured. Each card gives the claim as the authors reported it, the source, and what the study cannot show.

Attribution accuracy

Whether an assistant can say where a piece of text came from.

  • Eight AI search tools were given excerpts from news articles and asked for the headline, publisher, date and URL. 1,600 queries were run (20 publishers, 10 articles each, 8 tools). Overall, more than 60 percent of queries were answered incorrectly. Perplexity answered 37 percent incorrectly and Grok 3 answered 94 percent incorrectly. ChatGPT incorrectly identified 134 of 200 articles, and DeepSeek misattributed the source in 115 of 200 queries.

    Source
    We compared eight AI search engines. They are all bad at citing news ↗. Columbia Journalism Review, Tow Center for Digital Journalism. Published 2025-03-06. Checked 2026-10-08.
    Limitation
    Tests ran in February 2025 with each excerpt queried once. The authors say results should not be extrapolated to all models or publishers, and that outputs vary between runs. The task (identify a known article from an excerpt) is narrower than everyday question answering. Per-tool percentages for ChatGPT and DeepSeek are counts reported by the authors, not percentages they stated.
  • Journalists at 22 public service media organisations in 18 countries reviewed more than 3,000 answers from ChatGPT, Copilot, Gemini and Perplexity. 45 percent of answers had at least one significant issue. Source references were missing or misleading in 31 percent of cases, and 20 percent had major accuracy issues. Gemini had significant issues in 76 percent of its answers, the highest of the four.

    Source
    Largest study of its kind shows AI assistants misrepresent news content in 45% of cases ↗. VRT (reporting the EBU and BBC study, News Integrity in AI Assistants). Published 2025-10-22. Checked 2026-10-08.
    Limitation
    Figures are taken from a participating broadcaster's summary. The primary EBU report was not retrievable during this review and should be read before the numbers are reused. The questions concerned news events, not climate science or practice.

Whether citations support the claim

A link is present. Whether the page behind it backs the sentence is a separate question.

  • Human evaluators audited four generative search engines (Bing Chat, NeevaAI, Perplexity.ai, YouChat). On average, 51.5 percent of generated sentences were fully supported by their citations (citation recall), and 74.5 percent of citations supported the sentence they were attached to (citation precision).

    Source
    Evaluating Verifiability in Generative Search Engines ↗. arXiv:2304.09848 (Liu, Zhang, Liang), published in Findings of EMNLP 2023. Published 2023-04-19. Checked 2026-10-08.
    Limitation
    The systems audited date from early 2023 and have since changed or closed. Per-engine figures were not checked against the paper tables and are left out. The result shows the shape of the problem, not the current state.

What readers do with sources

Citations only matter if they are followed.

  • Among 900 US adults whose browsing was tracked in March 2025, users clicked a conventional result in 8 percent of visits to Google pages with an AI summary and 15 percent of visits to pages without one. About 1 percent of visits with a summary included a click on a link inside the summary. 26 percent of visits with a summary ended the browsing session, against 16 percent without.

    Source
    Google users are less likely to click on links when an AI summary appears in the results ↗. Pew Research Center. Published 2025-07-22. Checked 2026-10-08.
    Limitation
    Google only. Search results were re-collected weeks after the browsing period, so summaries may differ from what users saw. Only the first three cited links were checked for clicks, and click logs do not show intent or what was read.

Whose expertise appears

Who is named when an assistant answers a question about practice.

  • A 30-question interview on ecological restoration was put to ChatGPT 1,000 times each, producing 30,000 answers. Over two-thirds of answers drew on expertise from male academics at US universities. Evidence from low- and lower-middle-income countries made up 7 percent of answers, and Indigenous and community restoration experiences 2 percent.

    Source
    AI chatbots contribute to global conservation injustices ↗. Humanities and Social Sciences Communications (Urzedo and colleagues), summarised by CSIRO. Published 2024. Checked 2026-10-08.
    Limitation
    One model (ChatGPT) and one domain, without live search. Figures were read from the CSIRO summary because the journal page could not be fetched; month of publication was not confirmed. It concerns who is named as expertise, not which web pages are cited.

Language and retrieval

What is surfaced when the question is not asked in English, or concerns places outside the Anglophone press.

  • Six commercial chatbots were tested on 2,100 factual questions drawn from same-day BBC News reporting across six regional services (US and Canada, Arabic, Afrique, Hindi, Russian, Turkish). Every model scored lowest on Hindi (79 percent, against 89 to 91 percent for other regions). Retrieval failures accounted for over 70 percent of errors. For Hindi queries, models cited English Wikipedia more often than any Hindi-language outlet, which the authors read as an Anglophone retrieval bias.

    Source
    Evaluating Commercial AI Chatbots as News Intermediaries ↗. arXiv:2605.22785 (Suzgun and colleagues), preprint. Published 2026-05-21. Checked 2026-10-08.
    Limitation
    Preprint, not peer reviewed. Fourteen-day evaluation window in February 2026, and the questions concern news events. Figures were read from the arXiv abstract page, not the full text.

What is still unknown

Open questions

  • No source reviewed here measures which sources AI systems cite when asked about climate and sustainability practice across languages. The closest evidence concerns news, one restoration domain, and systems that have since changed.
  • It is not established how much source concentration comes from model training, from the retrieval layer, or from publisher access rules such as crawler blocking.
  • Citation accuracy figures come from different tasks (identifying an article, supporting a sentence, answering a news question). They are not directly comparable and are not shown as one ranking.
  • A grounded climate assistant built on IPCC reports has been published (ChatClimate, Communications Earth and Environment, 2023). Its findings were not verified during this review and are not summarised here.
  • Whether people check citations when the answer looks plausible is only partly known. The Pew data show low click-through to summary links on Google, not why.

Proposed method

How an independent study would work

This is a plan, not a result. No data have been collected under it.

  1. 01

    Fix a question set

    Draft a small, public set of climate and sustainability questions, written with practitioners, in several languages and covering both widely reported and locally documented topics. Publish the questions before any results.

  2. 02

    Fix the systems and the settings

    Record each assistant, version, interface, region, language setting and date of query. Repeat each question more than once, since outputs vary between runs.

  3. 03

    Capture everything

    Save the full answer, every cited link, and any sources shown but not cited. Note links that fail to resolve.

  4. 04

    Code the sources

    Classify each cited domain by type (government, multilateral, academic, news, advocacy, encyclopaedia, commercial), country and language. Two coders, with disagreements recorded.

  5. 05

    Check attribution

    For a sample of sentences, test whether the cited page supports the claim, using the recall and precision definitions from Liu and colleagues so results can be compared with earlier work.

  6. 06

    Compare against known knowledge

    Where an authoritative local or regional source exists for a question, record whether it was surfaced, and what was surfaced instead.

  7. 07

    Publish with limits

    Release data, prompts and coding rules with a plain account of what the sample cannot show. Invite correction before conclusions are drawn.

Source list

Sources

All links last checked 2026-10-08. Where a primary document could not be retrieved, the entry says so.

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