The art and science of search engine optimization (SEO) changed dramatically in recent years, thanks in no small part to big Google algorithm tweaks, including the recent mobile friendly update.\nJust as important as mobile, however, is voice. Professionals who practice SEO must prepare for a future in which queries come from voice input on mobile devices, and where Google, to satisfy those voice (and text) queries, will increasingly highlight "direct answers."\nGoogle (and to a lesser extent, Bing) searches yield direct answer results, also known as "rich answers," in response to specific user questions, instead of delivering an assortment of links to other websites.\n[Related: How to prepare for Google's next major search update]\nFor instance, if you ask, "What are the time zones in Russia," Google displays a table of the country's time zones atop related search results. In many cases, direct answers fulfill queries and eliminate the need to click links to get answers.\n\nWith direct answers, Google's goal is to provide the best possible user experience by answering questions in searches as quickly as possible. Google stressed the value of direct answers in a 2014 annual report it filed with the U.S. Securities and Exchange Commission:\u00a0\n\n"We used to show just ten blue links in our (search) results. You had to click through to different websites to get your answers, which took time. Now we are increasingly able to provide direct answers \u2014 even if you're speaking your question using Voice Search \u2014 which makes it quicker, easier and more natural to find what you're looking for."\u00a0\n\nOf course, the rise of voice search and direct answers have ramifications for websites and SEO practices, including the need to add more structured data to sites and provide clear answers to specific questions early in online content.\nHere's what digital marketers, content creators and SEO experts need to know about voice search, direct answers, and their effects on modern SEO.\nSiri, Google Now take voice search mainstream\nBefore Apple integrated Siri into the iPhone 4s in October 2011, voice search was practically nonexistent. However, the game changed, and Siri is now built into all new iPhones, iPads, iPod touch media players and the Apple Watch. Google Now, Google's voice-search technology, debuted in June 2012 as part of Android 4.1 "Jelly Bean." Microsoft's Cortana virtual assistant, demonstrated for the first time in April 2014, is now built into Windows Phone 8.1, and it will be part of the upcoming Windows 10 OS that's due this summer.\nAs of last fall, 41 percent of adults and 55 percent of teens used Siri, Google Now or Cortana voice search at least once per day, according to a Northstar Research study that was commissioned by Google.\u00a0\nThe accuracy of speech-recognition tech improved markedly in recent years, which is helping to increase the overall volume of voice searches. As of April, Google had an error rate of 8 percent compared to about 25 percent a few years ago, according to USA Today. The accuracy increase is largely related to faster processing power, along with enhancements in machine learning and natural language processing.\nDirect answers to voice searches on the rise\nIn a recent evaluation of more than 850,000 search queries, Google served up some form of direct answer 19.5 percent of the time, according to Eric Enge, CEO of Stone Temple Consulting, the company that conducted the test.\nTwo years ago, Google wouldn't have delivered any direct answers, Enge said at the Search Marketing Expo (SMX) West conference in March, where he presented the company's findings. A year ago, Google users would have received direct answers about 4 percent of the time, according to Enge. In comparison, Microsoft's Bing search engine currently delivers direct answers just 1.1 percent of the time.\n[Related: SEO and SEM tips for 2015]\nGoogle is likely to respond to voice searches with direct answers, rather than links, because most voice searches are currently performed on mobile devices and mobile users want immediate answers on their small screens, Enge said. (Google comprises nearly 65 percent of the overall search market, so it's no surprise that direct answers were a hot topic at SMX West 2015.)\nGoogle presents direct answers in various ways, according to Enge. In some cases, the search engine provides tabbed results. For example, queries related to movie showtimes or menus could receive tabbed results. And Google could provide answers within tables when a user asks, "Which teams played in the 2014 World Series?" Google also uses lists, Wikipedia entries, charts, forms, and carousels in its direct answers.\n\n\t\n\nTips to help marketers, publishers capitalize on direct answers\nVoice search and direct answers have a number of ramifications that website publishers and digital marketers should keep in mind. Here's a quick breakdown.\nIf you're hoping to draw traffic based on information that's within the public domain, you'd better have alternative plans, according to Enge. Of the 850,000 search queries Stone Temple Consulting evaluated, Google supplied direct answers to 42,160 of them using "public domain information," or basic facts, such as the capital of the state of California.\nIf you publish song lyrics on your site, you'll soon be singing the blues, because Google increasingly responds to song lyric queries with direct answers, Enge said.\nA site's "authority" has always been crucial for SEO, and it could be even more important in the future.\nGoogle chooses direct answer responses for "natural language" search queries, which can be performed via voice or text, from authoritative online sources, according to Bill Slawski, director of search marketing, Go Fish Digital. Sites that are frequently chosen in search results and that consistently rank highly in results for relevant queries are often deemed authoritative, based on a natural language search patent Google Israel filed in 2014, Slawski says.\u00a0\nFor example, the Google Israel researchers searched for pages that consistently rank highly for variations of specific questions, such as "how do I treat XY," "XY treatment," and "how to cure XY," Slawski says. Google researchers added those pages to a data store it is amassing, using headings such as "What are the symptoms of XY," along with specific answers to the questions.\u00a0(You can learn more about how to improve your site's domain authority on QuickSprout.com.)\nWebsites with content chosen by Google to supply direct answers can benefit from increased exposure, according to Slawski. Such sites can be seen as authoritative sources on the topics in question. Content chosen to supply direct answers is also formatted differently from other search results, and that could help content get noticed. It could also draw more traffic to a site, especially if Google's direct answers don't satisfactorily address users' questions.\nTo increase the odds of being featured in a direct answer, content marketers and SEO experts should focus on the specific questions their content answers and then address those questions immediately and clearly, according to Ehren Reilly, director of product for growth for job site Glassdoor.\nFor example, Google's direct answer for the search phrase, "Facebook software engineer salary," used to come from an article on the website AllFacebook.com, Reilly said. "Their article has a sentence that directly answers the question, and our page [on that topic] didn't."\n\nSo Glassdoor revised its page to clearly answer questions related to Facebook software engineer salaries, and now Google uses that page for its direct answer.\u00a0\nBottom line: If you want to be featured in a direct answer, "You need to know how to structure your ideas and take your page of content and place key points in places where [search engine] bots can see them and parse them out," according to Reilly.\n"Just like a resume, you need to know the formula for your content page," Reilly says. "Make sure you make the key point in clear, simple sentences."\nReilly also suggests studying the direct answers Google pulls from other sites for patterns, and then structuring your own content according to the findings. It's also a good idea to create large, exhaustive lists to answer questions, if feasible, according to Reilly. Google often can't place all of the relevant information in a direct answer box, so it will have to include a link to your site so users can find the rest of the information, which will help you get more traffic.\n"This is an opportunity to do a different kind of SEO from what you've been doing in the past," Reilly says. "And if you get in early, you'll have the advantage."