This is an explanatory essay about the Wikipedia:Verifiability policy.

This page provides additional information about concepts in the page(s) it supplements. This page is not one of Wikipedia's policies or guidelines as it has not been thoroughly vetted by the community.

WP:OFFLINE

This page in a nutshell: Offline sources are just as valid as online sources.

Wikipedia's reliable sources guideline states that articles should be sourced with reliable, third-party, published sources. Even though Wikipedia is an online encyclopedia, there is no distinction between using online versus offline sources. While many editors use online sources, such as websites and online journals, many great sources are only available offline in printed books and paper journals. Don't let the fact that a printed book or journal is not available online scare you away from using them as a source in Wikipedia. Likewise, do not remove cited material merely because it is from an offline source.

That Wikipedia relies extensively on online sources is not surprising, considering the relative ease of accessing such materials. There is also an additional advantage of using online sources, because it allows all users to evaluate the source and its value to the article. However, this reliance on online sources can lead to recentism, where most articles and content are from the Internet era. It can also lead to an unfair bias against print books and print journals, where an editor's addition of material sourced from a book or print journal is reverted with the comment "Revert - I couldn't access and confirm this source online."

Usage[edit]

Books are a typical example of an offline source. These are often great resources for history, philosophy and literature, and they often contain information that can't be found online. Several ongoing projects, such as Project Gutenberg, Internet Archive, NLA Trove and Google Book Search, aim at digitizing certain books or newspaper articles and presenting them online. Even if the books are online, it might be necessary to consult a print edition to double-check any errors from the OCR scanning.

Many academic journals only make short abstracts available online. Other content providers, like The Wall Street Journal, publish their content behind a paywall that prevents non-subscribers from accessing the content. Other websites, like the Philadelphia Inquirer, only publish their content online for a few weeks. Sometimes a source was once online, but now is offline (link rot).

Special care should be taken when using offline sources. Provision of full bibliographic information helps Wikipedia's readers and editors find the source when they need it, and also increases the source's credibility as a reliable source. This is often done by using a fully-filled out citation template such as ((cite book)) or ((cite news)). Use of the quote= parameter within those citation templates provides some context for the reference. This is especially important when using the off-line source to support a fact that might be controversial or is likely to be challenged. Providing identifiers such as an ISBN, OCLC number, Open Library number or similar can help others locate physical copies, as cataloguing data can often vary from one library to another.

Many offline sources are easier than you might think to find online. The Internet Archive full text search, as well as Internet Archive Scholar, are often able to provide a copy or snippet from millions of academic papers, books and even TV programs.

Challenging offline sources[edit]

Sometimes, the use of an offline source will be challenged. Be sure to assume good faith for the user who cited the offline source. They might even be able to provide you a scan or an excerpt from that source. Consider visiting your local library to obtain a copy. Even if the library doesn't have that particular book or journal article, it might be available through interlibrary loan. Also consider posting an inquiry on the relevant WikiProject, because some interested editors might have a copy of that source. The volunteers at WikiProject Resource Exchange might be able to help you coordinate your search.

See also[edit]

FUTON bias
Wikipedia:Resource requests
Wikipedia:Link rot
Wikipedia:Reliable sources/Cost
Wikipedia:Offline sources only, arguments to avoid in deletion discussions

Wikipedia essays (?)

Essays on building, editing, and deleting content

Philosophy	Article content Articles must be written All Five Pillars are equally important Avoid vague introductions Be a reliable source Civil POV pushing Cohesion Competence is required Concede lost arguments Dissent is not disloyalty Don't lie Don't search for objections Editing Wikipedia is like visiting a foreign country Editors will sometimes be wrong Eight simple rules for editing our encyclopedia Explanationism External criticism of Wikipedia Here to build an encyclopedia Leave it to the experienced Levels of competence Most ideas are bad Need Neutrality of sources Not editing because of Wikipedia restriction The one question Oversimplification Paradoxes Paraphrasing POV and OR from editors, sources, and fields Process is important Product, process, policy Purpose Reasonability rule Systemic bias There is no seniority Ten Simple Rules for Editing Wikipedia Tendentious editing The role of policies in collaborative anarchy The rules are principles Trifecta Wikipedia in brief Wikipedia is an encyclopedia Wikipedia is a community Wikipedia is not RationalWiki
Article construction	100K featured articles Abandoned stubs Acronym overkill Adding images improves the encyclopedia Advanced article editing Advanced text formatting Akin's Laws of Article Writing Alternatives to the "Expand" template Amnesia test A navbox on every page An unfinished house is a real problem Articles have a half-life Autosizing images Avoid mission statements Be neutral in form Beef up that first revision Blind men and an elephant BOLD, revert, discuss cycle Build content to endure Cherrypicking Chesterton's fence Children's lit, adult new readers, & large-print books Citation overkill Citation underkill Common-style fallacy Concept cloud Creating controversial content Criticisms of society may be consistent with NPOV and reliability Deprecated sources Dictionaries as sources Don't demolish the house while it's still being built Don't get hung up on minor details Don't hope the house will build itself Don't panic Don't "teach the controversy" Editing on mobile devices Editors are not mindreaders Encourage the newcomers Endorsements (commercial) Featured articles may have problems Formatting bilateral relations articles Formatting bilateral relations templates Fruit of the poisonous tree Give an article a chance How to write a featured article Identifying and using independent sources History sources Law sources Primary sources Science sources Style guides Tertiary sources Ignore STRONGNAT for date formats Inaccuracy Introduction to structurism Mine a source Merge Test Minors and persons judged incompetent "Murder of" articles Not every story/event/disaster needs a biography Not everything needs a navbox Not everything needs a template Nothing is in stone Obtain peer review comments Organizing disambiguation pages by subject area Permastub Potential, not just current state Presentism Principle of Some Astonishment The problem with elegant variation Pro and con lists Printability Pruning article revisions Publicists Put a little effort into it Restoring part of a reverted edit Robotic editing Sham consensus Source your plot summaries Specialized-style fallacy Stub Makers Run an edit-a-thon Temporary versions of articles Tertiary-source fallacy There are no shortcuts to neutrality There is no deadline There is a deadline The deadline is now Try not to leave it a stub Understanding Wikipedia's content standards Walled garden What an article should not include Wikipedia is a work in progress Wikipedia is not a reliable source Wikipedia is not being written in an organized fashion The world will not end tomorrow Write the article first Writing better articles
Writing article content	Avoid thread mode Copyediting reception sections Coup Don't throw more litter onto the pile Gender-neutral language Myth vs fiction Proseline Use our own words We shouldn't be able to figure out your opinions Write the article first Writing about women Writing better articles
Removing or deleting content	Adjectives in your recommendations AfD is not a war zone Arguments to avoid in deletion discussions Arguments to avoid in deletion reviews Arguments to avoid in image deletion discussions Arguments to make in deletion discussions Avoid repeated arguments Before commenting in a deletion discussion But there must be sources! Confusing arguments mean nothing Content removal Counting and sorting are not original research Delete or merge Delete the junk Deletion is not cleanup Does deletion help? Don't attack the nominator Don't confuse stub status with non-notability Don't overuse shortcuts to policy and guidelines to win your argument Follow the leader How to save an article proposed for deletion I just don't like it Identifying blatant advertising Identifying test edits Immunity Keep it concise Liar liar pants on fire Nothing Nothing is clear Overzealous deletion Relisting can be abusive Relist bias The Heymann Standard Unopposed AFD discussion Wikipedia is not Whack-A-Mole Why was the page I created deleted? What to do if your article gets tagged for speedy deletion When in doubt, hide it in the woodwork No Encyclopedic Use

Essays on civility

The basics	Accepting other users Apology Contributing to complicated discussions Divisiveness Edit at your own pace Encouraging the newcomers Enjoy yourself Expect no thanks High-functioning autism and Asperger's editors How to be civil Maintaining a friendly space Negotiation Obsessive–compulsive disorder editors Please say please Relationships with academic editors Thank you Too long; didn't read Truce Unblock perspectives We are all Wikipedians here You have a right to remain silent
Philosophy	A weak personal attack is still wrong Advice for hotheads An uncivil environment is a poor environment Be the glue Beware of the tigers! Civility warnings Deletion as revenge Failure Forgive and forget It's not the end of the world Nobody cares Most people who disagree with you on content are not vandals Old-fashioned Wikipedian values Profanity, civility, and discussions Revert notification opt-out Shadowless Fists of Death! Staying cool when the editing gets hot The grey zone The last word There is no Divine Right of Editors Most ideas are bad Nothing is clear Reader The rules of polite discourse There is no common sense Two wrongs don't make a right Wikipedia is not about winning Wikipedia should not be a monopoly Writing for the opponent
Dos	Assume good faith Assume the assumption of good faith Assume no clue Avoid personal remarks Avoid the word "vandal" Be excellent to one another Beyond civility Call a spade a spade Candor Deny recognition Desist Discussing cruft Drop the stick and back slowly away from the horse carcass Encourage full discussions Get over it How to lose Imagine others complexly Just drop it Keep it concise Keep it down to earth Mind your own business Say "MOBY" Mutual withdrawal Read before commenting Settle the process first
Don'ts	ALPHABETTISPAGHETTI Civil POV pushing Cyberbullying Don't accuse someone of a personal attack for accusing of a personal attack Don't be a fanatic Don't be a jerk Don't be an ostrich Don't be ashamed Don't be a WikiBigot Don't be high-maintenance Don't be inconsiderate Don't be obnoxious Don't be prejudiced Don't be rude Don't be the Fun Police Don't bludgeon the process Don't call a spade a spade Don't call people by their real name Don't call the kettle black Don't call things cruft Don't come down like a ton of bricks Don't cry COI Don't demand that editors solve the problems they identify Don't drink the consensus Kool-Aid Don't eat the troll's food Don't fight fire with fire Don't give a fuck Don't help too much Don't ignore community consensus Don't knit beside the guillotine Don't make a smarmy valediction part of your signature Don't remind others of past misdeeds Don't shout Don't spite your face Don't take the bait Don't template the regulars Don't throw your toys out of the pram Do not insult the vandals Griefing Nationalist editing No angry mastodons just madmen No Nazis No racists No Confederates No, you can't have a pony Passive aggression Please don't bite the newcomers POV railroad Superhatting There are no oracles There's no need to guess someone's preferred pronouns You can't squeeze blood from a turnip UPPERCASE
WikiRelations	WikiBullying WikiCrime WikiHarassment WikiHate WikiLawyering WikiLove WikiPeace

Essays on notability

Humorous essays

About essays

About essays	Essay guide Value of essays Difference between policies, guidelines and essays Don't cite essays as if they were policy Avoid writing redundant essays Finding an essay Quote your own essay
Policies and guidelines	About policies and guidelines Policies Guidelines How to contribute to Wikipedia guidance Policy writing is hard