This political season, the issue of truth versus falsity was taken to new heights, or depths.

Just as with politics, the online world has a history of misinformation, disinformation, urban myths, rumors, conspiracy theories, and deception. The statement, “If it’s on the Internet, it has to be true,” is a good line in a TV ad. In truth, you need to be careful out there. But just as the Internet is a fount of falsehood, it’s also a source of tools for verifying the verity of statements and alleged facts.

As a general rule, the real-time communication that takes place with texting and chatting is the most unreliable. One level up in reliability are social media sites, Web forums, and other discussion groups in which people have more time to ponder their posts. Websites, in turn, are generally more reliable still because they have more permanence, so more care goes into creating the information on them.

Another reality of the online world is that anybody can play expert, and many do. You frequently see, for instance, lay people playing lawyer, offering legal opinions about complicated subjects and advising others on what’s legal and what’s not when it’s clear that all they’ve done is Googled a statute or court case.

Then there are the outright lies and similar statements that show no regard for the truth or falsity of the matter, only the agendas and biases of those behind them. The American comedian Stephen Colbert in a 2005 episode of his TV show The Colbert Report informally re-coined the word “truthiness” to mean knowing from the gut because it feels right and appealing to others’ emotions without regard for evidence, logic, or facts.

Lying has deep roots and a biological aspect. Deception is common in many species as a way of attracting or fooling prey or mates and otherwise promoting your survival or that of your offspring.

But deception that crosses the line, however that line is defined by any given society, is deemed unethical or illegal or both and has consequences. It’s also in our interest to be good at deception detection.

As a reader, it’s good to be skeptical, not cynical, about information you come across. The lesson that every school child learns is that you shouldn’t believe everything you read.

In asking yourself “Is it true?” also ask:

• Who’s behind the information? Different sources employ different levels of thoroughness in research and fact-checking and different levels of objectivity. 
• Why is the person or organization presenting the information? Individuals and organizations often have agendas, sometimes explicit, sometimes hidden. Advocacy groups and companies, for instance, have different reasons for putting out information than news organizations. 
• Is the information paid for? Ads and advertorials are inherently less reliable than other information. 
• Does the information diverge from my current understanding? If it diverges widely and may affect an important business, health, or family decision, try to verify the same information with at least two other sources. Your local librarian can be a valuable resource here. 
• Is the information new or old? A lot of deadwood data is floating around in cyberspace at websites that haven’t been updated in several years. If the site doesn’t include a “Last updated” line or otherwise date its content, check out some of its links. If more than a few are no longer working, the information at the site may no longer be up-to-date either. 

There are a number of good sites on the Web you can use for help in determining the accuracy of information you come across.

Snopes is the best general site for getting to the bottom of “urban legends, folklore, myths, rumors, and misinformation.” It was founded by a husband and wife team of researchers and writers, Barbara and David Mikkelson.

Naturally, misinformation has sprung up about it. One of the wackier rumors is that it’s funded by billionaire Marxists. Another is that its founders have been arrested on fraud and corruption charges.

It and other fact-checking sites are sometimes also accused of being smokescreens for corrupt politicians and the corrupt media, which is conspiracy thinking about those who debunk conspiracy thinking.

Other reliable fact-checking sites include FactCheck, Truth or Fiction, the Skeptic’s Dictionary, Emergent, Hoax Slayer, and PolitiFact. Wikiquote is a good site for checking the accuracy of quotes.

Whether online or off, the byword is, and will likely always remain, caveat lector—let the reader beware.