AI Writing & Content
7 Best AI Writing Tools for Academic Researchers & Students (2026)
7 tools compared
Top Picks
<p>Academic writing has always been a bottleneck. Not because researchers can't write, but because the process surrounding it — finding relevant papers, verifying citations, paraphrasing without distorting meaning, maintaining consistent academic tone across 50-page documents — eats time that should go toward actual research. A 2025 Carnegie Mellon study found that graduate students using AI tools reduced writing time by 65% while improving average grades from B+ to A. The tools are no longer optional for competitive academic work.</p><p><strong>But most "best AI writing tools" lists mix academic-grade tools with marketing platforms.</strong> Jasper and Frase are excellent for SEO content — they'll help you rank a blog post on Google. They won't help you write a properly cited literature review or verify whether a foundational paper in your field has been contradicted by subsequent research. Academic writing has specific requirements that generic AI tools can't meet: citation accuracy, plagiarism-safe paraphrasing, access to peer-reviewed databases, and outputs that pass institutional AI detection policies.</p><p>The biggest risk with AI in academia isn't using it — it's using the <em>wrong</em> tool. General-purpose LLMs like ChatGPT will confidently generate citations that don't exist. They'll paraphrase in ways that trigger plagiarism detectors. They'll produce text that reads like a blog post, not a journal article. The tools in this guide are built specifically for scholarly work: they search peer-reviewed literature, generate verifiable citations, and integrate with the workflows researchers and students actually use.</p><p>We evaluated these seven tools on five criteria that matter for academic work: <strong>citation accuracy</strong> (does it reference real papers?), <strong>literature coverage</strong> (how many peer-reviewed sources does it search?), <strong>academic integrity</strong> (will it trigger AI detectors?), <strong>workflow integration</strong> (does it work with Zotero, Word, Google Docs?), and <strong>cost accessibility</strong> (can a grad student afford it?). Browse all <a href="/categories/ai-writing-content">AI writing and content tools</a> in our directory, or explore <a href="/categories/education-learning">education and learning tools</a> for related picks.</p>
Full Comparison
AI for scientific research
💰 Free basic plan with 5,000 one-time credits. Plus from $12/mo, Pro from $49/mo, Team from $79/user/mo
<p><a href="/tools/elicit">Elicit</a> is the <strong>most rigorous AI research tool available for systematic evidence synthesis</strong>. While other tools help you find papers, Elicit helps you extract structured data from them at scale — a capability that's transformative for anyone conducting systematic reviews, meta-analyses, or evidence-based research. Ask a research question, and Elicit searches 125 million+ academic papers using semantic search, then builds customizable evidence tables where you define the columns (sample size, methodology, key findings, effect sizes) and the AI extracts the data from each paper with sentence-level citations.</p><p>The sentence-level citation system is what sets Elicit apart from every general-purpose AI tool. Every claim the AI makes links to the <em>exact sentence</em> in the source paper, not just the paper itself. This dramatically reduces hallucination risk — and gives you a direct path to verification. Formation Bio reported reducing hundreds of hours of literature review work to approximately 10 hours across 300 papers using Elicit's extraction pipeline. For PhD students facing a wall of papers to screen, that kind of time savings can change the trajectory of a dissertation.</p><p>The honest limitation is that Elicit is <strong>strongest in biomedical, clinical, and quantitative research fields</strong>. Humanities and qualitative social science researchers will find the structured extraction approach less natural for their work. The free tier is also genuinely limited — 5,000 one-time credits that don't refresh monthly, meaning serious users will need the Plus plan at $12/month fairly quickly. But for anyone doing evidence synthesis with quantitative data, Elicit is the closest thing to having a trained research assistant who never sleeps.</p>
Semantic Paper SearchAutomated Literature ReviewData Extraction TablesPDF Upload & AnalysisAutomated ReportsSystematic Review SupportCSV / BIB / RIS ExportResearch AlertsSentence-Level Citations
Pros
- Sentence-level citations on every AI claim reduce hallucination risk far below general-purpose LLMs
- Structured evidence tables with custom columns enable systematic data extraction across thousands of papers
- Semantic search across 125M+ papers consistently surfaces relevant studies that keyword searches miss
- Proven time savings — users report reducing literature review work from hundreds of hours to single digits
- CSV, BIB, and RIS export integrates seamlessly with reference managers like Zotero and Mendeley
Cons
- Free tier credits are one-time only and don't refresh — serious users hit the paywall quickly
- Strongest in biomedical and quantitative fields; less useful for humanities and qualitative research
- Steeper learning curve than conversational tools — the structured workflow takes time to master
Our Verdict: Best for PhD students, systematic reviewers, and evidence-based researchers who need structured data extraction from large volumes of papers with verifiable, sentence-level citations.
AI research agent with 150+ tools and 280M+ papers
💰 Free Basic plan available. Premium from $12/mo (annual) or $20/mo. Teams from $8/seat/mo (annual) or $18/seat/mo. Advanced at $70/mo.
<p><a href="/tools/scispace">SciSpace</a> (formerly Typeset.io) is the <strong>most comprehensive all-in-one platform for academic research workflows</strong>. It combines paper discovery, PDF analysis, literature review generation, manuscript writing, and journal matching in a single workspace — covering more of the research lifecycle than any other tool on this list. The Deep Review agent is the headline feature: it autonomously searches 280 million+ publications, identifies relevant papers, extracts key findings, and synthesizes them into a structured literature review draft with proper citations.</p><p>The <strong>Chat with PDF feature</strong> is where SciSpace shines for students. Upload a dense, jargon-heavy paper, and ask questions about it in plain language. "What methodology did they use?" "How does this compare to Smith et al. 2023?" "Explain equation 3 in simple terms." The AI responds with highlighted source locations in the document, so you can verify every explanation. For grad students reading outside their primary expertise — or undergrads encountering academic papers for the first time — this turns impenetrable research into accessible knowledge.</p><p>SciSpace also includes <strong>Insight Tables</strong> for comparing methods, findings, and data points across multiple papers side-by-side, an AI Writer with auto-citation from its 280M paper database, an AI Detector for checking whether text reads as AI-generated, and a Journal Matcher for finding the best submission targets. The main drawback is pricing: while the free tier lets you try core features, the Advanced plan at $70/month is steep for individual students. Check whether your institution has a Teams license ($8/seat/month annually) — many universities are adopting SciSpace for lab and classroom use.</p>
AI Literature ReviewChat with PDFAI WriterAI Research AgentsSemantic Paper SearchInsight TablesAI DetectorJournal MatcherCitation GeneratorMulti-Language Support
Pros
- Deep Review agent conducts automated literature reviews across 280M+ papers with structured synthesis
- Chat with PDF provides plain-language explanations of complex papers with highlighted source locations
- Insight Tables enable side-by-side comparison of methods and findings across multiple studies
- Covers the full research lifecycle: discovery, analysis, writing, citation, and journal matching in one platform
- Multi-language support makes it accessible to researchers working in non-English academic traditions
Cons
- Advanced plan at $70/month is expensive for individual students without institutional licensing
- Credits can run out quickly on premium plans during intensive research periods
- Occasional hallucinated references that require manual verification before citing
Our Verdict: Best all-in-one research platform for graduate students and early-career researchers who need literature review automation, PDF analysis, and manuscript writing in a single workspace.
AI search engine that finds answers in scientific research
💰 Free tier with limited searches, Premium from $12/mo (billed annually), Enterprise custom
<p><a href="/tools/consensus">Consensus</a> answers a question that no other tool on this list does: <strong>"What does the scientific evidence actually say about this?"</strong> Instead of returning a list of papers and leaving you to synthesize them, Consensus analyzes 200 million+ peer-reviewed papers and delivers a direct answer with a visual Consensus Meter showing how much of the evidence agrees, disagrees, or is mixed. For researchers writing background sections, students building arguments, or anyone who needs to quickly assess the state of evidence on a topic, this is research validation at a speed that used to be impossible.</p><p>The <strong>Deep Search feature</strong> takes this further by conducting what amounts to an automated mini-literature review. It builds a search strategy, expands key terms, explores citation graphs, and synthesizes findings into a structured report with introduction, methods, results, and conclusions. For a student writing a thesis proposal who needs to establish that a research gap exists, or a professor preparing a grant application who needs to cite the current consensus on a foundational claim, Deep Search produces a usable first draft of that evidence summary in minutes rather than days.</p><p>Consensus is <strong>deliberately limited to peer-reviewed academic literature</strong> — it won't answer general knowledge questions or search the open web. This is a feature, not a bug: every result comes from a real published paper indexed by Semantic Scholar, eliminating the hallucination risk that plagues general-purpose AI. The 40% student discount on Premium ($12/month) makes it one of the most student-accessible tools here, and 170+ university libraries have adopted it institutionally. The main limitation is that it works best for fields with large bodies of quantitative research; humanities scholars and those in emerging fields with thin publication records will find fewer useful results.</p>
Consensus MeterDeep SearchAsk Paper200M+ Paper DatabaseStudy SnapshotsAdvanced FilteringThreadsChatGPT Integration
Pros
- Consensus Meter instantly visualizes scientific agreement — no manual synthesis needed for yes/no research questions
- Searches exclusively peer-reviewed literature, eliminating web noise and hallucinated sources entirely
- Deep Search automates mini-literature reviews with structured output suitable for background sections
- 40% student discount and generous free tier (25 Pro Analyses/month) make it accessible for academic budgets
- 170+ university library partnerships and growing institutional adoption signal long-term reliability
Cons
- Limited to academic and scientific topics — won't help with general writing or non-research queries
- Results depend on Semantic Scholar's index, which may miss very recent or niche publications
- Strongest in biomedical and quantitative fields; weaker coverage in humanities and social sciences
Our Verdict: Best for quickly assessing scientific consensus on research questions, writing evidence-based background sections, and validating claims with peer-reviewed sources.
AI-powered writing assistant for clear, effective communication
💰 Free plan available. Pro starts at $12/month (billed annually). Enterprise pricing available on request.
<p><a href="/tools/grammarly">Grammarly</a> needs no introduction to most academics — it's the <strong>most widely adopted writing assistant in higher education</strong>, with over 30 million daily active users. But Grammarly's value for academic writing goes well beyond catching typos. The 2026 version includes tone detection that flags when your writing shifts from academic to conversational, full-sentence rewrites that maintain scholarly register, and a plagiarism checker that scans 400+ billion sources including academic databases. For non-native English speakers writing in English-language journals — which is the majority of global researchers — Grammarly is often the difference between a desk rejection and peer review.</p><p>The <strong>Authorship feature</strong> is particularly relevant for academics navigating institutional AI policies. It tracks which text you wrote yourself, which was AI-assisted, and which was pasted from other sources, creating an audit trail that demonstrates your intellectual contribution. As universities develop clearer AI disclosure requirements, this kind of provenance tracking will likely become standard practice. GrammarlyGO, the generative AI component, can draft paragraphs, rewrite for clarity, and adjust tone — useful for quickly iterating on abstract revisions or cover letter drafts.</p><p>Grammarly's limitation in an academic context is that it's a <strong>writing polisher, not a research tool</strong>. It won't find papers, generate citations, or synthesize literature. It makes your existing writing better, not smarter. For researchers, the optimal workflow pairs Grammarly with a research discovery tool like Elicit or Consensus: use the discovery tool to find evidence and build arguments, then use Grammarly to ensure the final manuscript is grammatically precise, properly toned, and free of unintentional plagiarism. The free tier handles basic grammar; Pro at $12/month adds the plagiarism checker and advanced rewrites that most academics need.</p>
Real-Time Grammar CheckingGrammarlyGO Generative AITone & Style DetectionPlagiarism DetectionFull-Sentence RewritesCross-Platform IntegrationCustom Style GuidesTeam Analytics
Pros
- Most mature grammar and tone engine — catches nuanced errors that simpler checkers miss
- Plagiarism detection against 400+ billion sources including academic papers and databases
- Authorship feature tracks AI-assisted vs. original text for institutional compliance and disclosure
- Works everywhere — browser extension, desktop app, Google Docs, Microsoft Word, and mobile
- Clear explanations for every suggestion help non-native speakers improve their English writing over time
Cons
- English-only — no support for multilingual academic writing or non-English manuscripts
- Writing polisher only — no research discovery, citation management, or literature review capabilities
- Advanced features like plagiarism checking and full-sentence rewrites require Pro at $12/month
Our Verdict: Best for manuscript polishing, plagiarism prevention, and academic tone consistency — especially valuable for non-native English speakers preparing journal submissions.
AI-powered smart citations that show how research has been cited — supported, contrasted, or mentioned
💰 Free 7-day trial, Individual from $12/mo, institutional and custom plans available
<p><a href="/tools/scite">scite</a> does something no other tool in this guide can do: it tells you <strong>whether the papers you're citing have been supported or contradicted by subsequent research</strong>. Traditional citation counts tell you how often a paper was referenced — but a paper cited 500 times might be cited because 400 of those citations are refuting it. scite's Smart Citations classify 1.6 billion+ citation statements into three categories: supporting, contrasting, or mentioning. This transforms citation analysis from a popularity contest into an evidence quality assessment.</p><p>The <strong>Reference Check feature</strong> is where scite becomes indispensable for manuscript preparation. Upload your draft, and scite instantly analyzes every paper in your reference list, showing whether each has been supported, contradicted, or retracted since publication. For researchers about to submit a paper, this is a critical quality control step — citing a retracted or heavily contradicted study can undermine your entire manuscript during peer review. The browser extension (Chrome, Firefox, Safari) overlays Smart Citation data on any paper you read online, integrating this intelligence into your existing research workflow without requiring you to change habits.</p><p>scite's main barrier is <strong>accessibility for students</strong>. There's no free tier — only a 7-day trial before the $12/month Individual plan kicks in. Coverage is also uneven: STEM fields have rich Smart Citation data, but humanities and social sciences have significantly thinner coverage. And while the concept of supporting vs. contrasting citations is powerful, it requires researchers to think about citations differently, which adds a learning curve. For anyone writing in well-published STEM fields, though, scite provides a layer of citation intelligence that genuinely doesn't exist anywhere else.</p>
Smart CitationsCitation Statement SearchAI Research AssistantCustom DashboardsBrowser ExtensionReference CheckPublisher IntegrationsVisualizations
Pros
- Smart Citations uniquely classify 1.6B+ citation statements as supporting, contrasting, or mentioning
- Reference Check instantly verifies whether your cited papers have been contradicted or retracted
- Browser extension integrates citation intelligence into existing research workflows on any website
- Custom dashboards with real-time alerts track new citations to papers you care about
- NSF and NIH-funded development signals rigorous academic standards behind the platform
Cons
- No free tier — only a 7-day trial before requiring the $12/month Individual subscription
- Coverage significantly stronger in STEM than humanities and social sciences
- Learning curve around the supporting/contrasting framework that traditional citation tools don't require
Our Verdict: Best for researchers who need to verify whether their citations are well-supported by subsequent research — an essential manuscript quality-check tool for STEM fields.
AI-powered writing and paraphrasing suite
💰 Free plan with basic features, Premium from $8.33/mo billed annually
<p><a href="/tools/quillbot">QuillBot</a> is the <strong>go-to paraphrasing tool for academic writing</strong>, and for good reason: it offers 10+ paraphrasing modes with a synonym slider that gives you granular control over how much the output diverges from the original. For students who need to incorporate source material without direct quoting, or researchers rewording their own prior work to avoid self-plagiarism, this level of control matters. The Standard and Fluency modes preserve meaning while restructuring sentences; the Creative and Expand modes work well for turning concise notes into fuller paragraphs.</p><p>Beyond paraphrasing, QuillBot bundles a <strong>full academic writing toolkit</strong>: grammar checker, plagiarism detector, summarizer, translator (30+ languages), and a citation generator supporting APA, MLA, Chicago, and other styles. The summarizer is particularly useful for reading-heavy coursework — paste a 5,000-word paper and get a paragraph-length summary or key bullet points. The Chrome extension (4.8-star rating) works directly inside Google Docs, which is where many students do their writing. At $8.33/month for Premium (billed annually), it's also the most affordable paid tool in this guide.</p><p>The academic-specific limitation is that <strong>QuillBot paraphrases text, but doesn't understand it</strong>. In technical or specialized writing, the paraphraser can subtly change meaning — swapping a precise term for a near-synonym that means something different in context. A biology student paraphrasing about "cell differentiation" might get output that says "cell distinction," which is technically wrong. Every paraphrased passage needs careful human review, especially in fields with precise terminology. QuillBot is best used as a starting point for rewording, not a finished product.</p>
AI ParaphraserGrammar CheckerPlagiarism CheckerAI HumanizerSummarizerCitation GeneratorTranslatorCo-WriterBrowser Extension
Pros
- 10+ paraphrasing modes with synonym slider provide unmatched control over output variation
- Most affordable paid option at $8.33/month with a functional free tier for light usage
- All-in-one suite: grammar checker, plagiarism detector, summarizer, translator, and citation generator
- Chrome extension works directly inside Google Docs for seamless academic workflow integration
- AI Humanizer helps ensure paraphrased text doesn't trigger AI detection tools
Cons
- Paraphraser can subtly distort meaning in technical writing — requires careful review of specialized terminology
- Free plan limits paraphrasing to 125 words per input, which is impractical for longer passages
- No research discovery or literature search capabilities — purely a writing and editing tool
Our Verdict: Best affordable paraphrasing tool for students who need to incorporate source material safely, with a comprehensive writing suite that covers grammar, plagiarism, citations, and summarization.
AI-powered academic writing and research assistant
💰 Free plan with 200 words/day, Unlimited from \u002412/mo
<p><a href="/tools/jenni">Jenni AI</a> is the only tool on this list that functions as a <strong>true AI co-writer for academic documents</strong>. While Grammarly polishes text you've already written and QuillBot paraphrases existing sources, Jenni sits beside you as you draft, offering real-time AI autocomplete that suggests the next sentence based on your context, tone, and cited sources. For students staring at a blank page with a deadline approaching, this is the most direct solution to academic writer's block.</p><p>The academic-specific features set Jenni apart from generic AI writing tools. <strong>In-text citations</strong> are generated automatically as you write, pulling from your uploaded PDFs and Jenni's paper database in APA, MLA, Chicago, and other styles. The literature review generator takes your research topic and uploaded sources, then produces a structured review draft with proper citations — not a finished product, but a substantial starting point that saves hours of initial drafting. The outline builder helps structure essays and papers before you start writing, which is particularly valuable for undergraduates who struggle with paper organization.</p><p>The trade-off with Jenni is <strong>depth vs. speed</strong>. The AI autocomplete prioritizes fluency over rigor — it generates text that reads smoothly but may lack the analytical depth that graduate-level work requires. Generated citations, while real, occasionally include inaccurate references that need manual verification. The free tier at 200 words per day is too restrictive for meaningful academic work, effectively requiring the $12/month Unlimited plan for any serious use. Jenni is most valuable for <strong>undergraduates and early graduate students</strong> who need help getting words on the page and structuring their arguments, less so for experienced researchers who think faster than they type.</p>
AI AutocompleteIn-Text CitationsAI Chat for ResearchOutline BuilderLiterature Review GeneratorPlagiarism CheckerAI Editing & ParaphrasingPDF Upload & Analysis
Pros
- Real-time AI autocomplete helps overcome writer's block by suggesting contextually appropriate next sentences
- Automatic in-text citation generation in APA, MLA, Chicago, and other styles as you write
- Literature review generator produces structured drafts from uploaded sources, saving hours of initial work
- Outline builder helps students organize paper structure before drafting begins
- Purpose-built for academic writing — maintains scholarly tone unlike generic AI writers
Cons
- AI-generated text can lack analytical depth required for graduate-level argumentation
- Generated citations occasionally include inaccurate references requiring manual verification
- Free tier at 200 words/day is too limited for meaningful academic work — effectively requires the $12/month plan
Our Verdict: Best for undergraduates and early graduate students who need an AI co-writer that generates properly cited academic text and helps overcome the blank-page problem.
Our Conclusion
<h3>Quick Decision Guide</h3><ul><li><strong>You're conducting a systematic review or meta-analysis</strong> → <a href="/tools/elicit">Elicit</a>. No other tool matches its structured data extraction across thousands of papers with sentence-level citations and 94-99% accuracy.</li><li><strong>You need to understand dense papers quickly and build literature reviews</strong> → <a href="/tools/scispace">SciSpace</a>. The Chat with PDF feature and Deep Review agent turn weeks of reading into hours of structured synthesis.</li><li><strong>You want to know if the research you're citing actually holds up</strong> → <a href="/tools/scite">scite</a>. Smart Citations showing supporting vs. contrasting evidence is genuinely unique — no other tool classifies 1.6 billion citations this way.</li><li><strong>You need an evidence-based answer to a research question, fast</strong> → <a href="/tools/consensus">Consensus</a>. The Consensus Meter instantly visualizes scientific agreement across hundreds of studies.</li><li><strong>You're polishing a manuscript for submission</strong> → <a href="/tools/grammarly">Grammarly</a>. The most mature grammar and tone engine, with plagiarism detection and the Authorship feature for tracking AI-assisted text.</li><li><strong>You need to paraphrase source material without plagiarism risk</strong> → <a href="/tools/quillbot">QuillBot</a>. Ten paraphrasing modes with a synonym slider give you granular control over how much the text changes.</li><li><strong>You're drafting a paper from scratch and want AI to write alongside you</strong> → <a href="/tools/jenni">Jenni AI</a>. Purpose-built for academic drafting with inline citations and literature review generation.</li></ul><h3>Our Top Pick</h3><p><strong>For most academic users, start with Elicit + Grammarly.</strong> Elicit handles the research-heavy front end — finding papers, extracting data, synthesizing evidence — while Grammarly handles the writing-heavy back end — polishing prose, checking plagiarism, and ensuring academic tone. Both have usable free tiers, and together they cover the full research-to-submission pipeline without overlap.</p><p>One critical rule: <strong>never trust AI-generated citations without verification.</strong> Even the best tools in this list occasionally hallucinate references or misattribute findings. Treat every AI citation as a lead, not a fact — click through to the actual paper before including it in your work. For more research-focused tools, see our guide to <a href="/best/best-open-source-bi-data-visualization-tools">open-source data visualization tools</a>, or browse our <a href="/best/best-ai-writing-assistants-long-form-content">best AI writing assistants for long-form content</a> if your needs extend beyond academia.</p>
Frequently Asked Questions
Can I use AI writing tools without violating academic integrity policies?
Yes, but it depends on how you use them and your institution's specific policies. Most universities now distinguish between AI as a research assistant (acceptable) and AI as a ghostwriter (not acceptable). Tools like Elicit and Consensus that help you find and synthesize existing research are generally permitted. Writing assistants like Grammarly for grammar and tone are almost universally accepted. The key is transparency: disclose AI tool usage per your institution's guidelines, verify all AI-generated citations manually, and ensure the intellectual contribution — the arguments, analysis, and conclusions — is your own work.
Which AI tool is best for writing a literature review?
SciSpace and Elicit are the strongest options, but they serve different stages. SciSpace's Deep Review agent builds structured literature review drafts by searching 280M+ papers, synthesizing findings, and organizing them thematically — ideal for getting a first draft quickly. Elicit excels at systematic, structured data extraction across large numbers of papers with evidence tables. For a typical thesis literature review, start with SciSpace for the initial survey and structure, then use Elicit to do deep extraction on the most relevant papers.
Do these AI tools generate fake or hallucinated citations?
The tools in this guide are significantly more reliable than general-purpose AI like ChatGPT because they search actual peer-reviewed databases rather than generating text from memory. Elicit and Consensus search 125M+ and 200M+ real papers respectively, linking claims to specific source sentences. scite goes further by classifying 1.6 billion actual citation statements. However, no tool is perfect — occasional errors occur, especially with less-cited or very recent papers. Always verify citations by clicking through to the original paper before including them in your work.
Are these tools affordable for students?
Most offer usable free tiers. Consensus gives 25 Pro Analyses and 3 Deep Searches per month for free, plus a 40% student discount on Premium. Grammarly's free tier covers basic grammar checking. QuillBot offers free paraphrasing (125 words at a time). Elicit provides 5,000 one-time credits. Jenni AI gives 200 words per day free. The most affordable paid options are QuillBot Premium at $8.33/month and Consensus/Elicit at $12/month. scite is the least accessible for students with no free tier. Check if your university has institutional licenses — many now provide campus-wide access to tools like Grammarly and Consensus.
What's the difference between a research discovery tool and a writing assistant?
Research discovery tools (Elicit, Consensus, SciSpace, scite) help you find, evaluate, and synthesize academic literature — they search paper databases, extract data, and verify citations. Writing assistants (Grammarly, QuillBot, Jenni AI) help you produce and polish text — grammar checking, paraphrasing, drafting, and formatting. Most academic workflows need both: a discovery tool for the research phase and a writing assistant for the drafting and editing phase. Some tools bridge both categories — SciSpace and Jenni AI include both literature search and writing features.