Disease in a Dish

Disease in a Dish

Generating cells from patients suffering from such disorders as  Down syndrome, schizophrenia, and ALS lets scientist study these diseases in the lab and test new drugs.

Just four years ago, scientists from the United States and Japan developed a way to create stem cells from human skin cells. Since then, researchers have used the technology to generate such cells from people with a variety of different diseases, including diabetes, Down syndrome, and Parkinson’s disease. By differentiating these cells into the cell type affected in the disease, scientists can search for molecular missteps unique to these cells. The findings are already beginning to shed light on these diseases and are being used as a tool to test new treatments.
Here, researchers created stem cells from patients with a rare neurological disease, familial dysautonomia, and then differentiated them into the specific neurons (shown labeled with red and blue markers) affected by the disease.  They found that the cells did not differentiate into neurons as readily as cells derived from healthy people, nor did they migrate as easily as normal cells. Researchers used the cells to test a handful of potential treatments for the disorder, identifying one candidate that reversed the defect in differentiation.

If Facebook Made a Phone, Would You Friend It?

Computing

If Facebook Made a Phone, Would You Friend It?

Experts weigh in on whether the concept would be a hit with users.

Why would you want to buy a "Facebook phone," if—as is widely rumored—one is under development?
Here's why: if social networking is already the center of your online activity, a Facebook smart phone might be far easier to use. If a fraction of Facebook's 800 million users were to make the switch, they would represent a powerful market force.
The phone project was revealed in reports last week that said Facebook had forged a partnership with handset maker HTC and was planning to use a version of the Android operating system, which will be tweaked to integrate Facebook deeply into its services and will support HTML5 as a platform for mobile games and apps. The reports said the phone could take 12 to 18 months to reach market. Facebook is saying nothing about the project; a spokesman said the company would not comment on "rumor and speculation."
Already, Facebook's are among the most popular apps on most smart phones. The company says that its apps on different platforms have 350 million active mobile users. The problem Facebook confronts is that its product is not very deeply "integrated," in industry parlance, into the devices that people use socially every day to e-mail, send photos, and keep in touch with friends.  It's just one of many apps people use.
For example, on an iPhone, if you open a Web page and click on the menu, you have the option of tweeting the link but not of sharing it on Facebook. That's because Twitter got itself integrated, and Facebook, for whatever reason, did not. On some Android phones, Facebook is integrated in this way, but it could be even better integrated into the devices.
To use an iPhone to send a link to your Facebook friends, you need to take more steps to open and use the Facebook app. And much the same problem pertains to reporting your location, sending a photo, playing games, or engaging in any of a host of other activities.
But on a Facebook phone, such functions could be the default option. And people would find it easier to use Facebook itself—making Facebook an even more titanic Hoover of personal information than it already is.
Facebook could go even further by directing all communications—including voice and text messaging—through its platform. And it could use that same platform to deliver content, including music and video, to users.

"This could potentially shift the paradigm of what social networking and mobility can be and should be," says Raymond Llamas, a senior research analyst for IDC's mobile devices group. "Consider this: a smart phone that automatically checks you in on your location, finds your friends in the same area, uploads pictures of what you do to Facebook for all your other Facebook friends to see."
The biggest challenge, Llamas says, would be convincing people to switch from existing phones, which do a pretty good job on many fronts, including providing a way to use Facebook via an app.
Then too, the company would have to expand the functionality of its phone beyond Facebook. "Here's the whole crux of the situation for them," says Mike Morgan, an analyst at ABI. "Is FB enough to make a device desirable? To this I would say no. The day of single-purpose devices has long since passed."
Chetan Sharma, a mobile communications consultant, says that Facebook's user base makes "entry into the [smart-phone] market compelling." However, he adds that simply adapting the Android operating system may not be enough. "If they want be serious longer term, they might have to own a platform. They could also entirely focus on HTML5-based platforms and services and avoid the investment" of developing apps for a new operating system.
Al Hilwa, program director for IDC's application development software group, says that in the long view, a giant like Facebook just needs to spread its reach, much the way Google branched out by launching the Android mobile platform and the Google+ social network. "If someone gets into your business, it's almost incumbent on you to get into their business—otherwise, you get into a situation where they block you out. That's not an immediate risk right now for Facebook, but that is one of the considerations. You want to try and own the whole data chain, end to end."
Indeed, ABI's Morgan says that a Facebook-centric smart phone is an obvious next step. "If Facebook wants a stronger mobile presence it needs to be deeply embedded so it can become part of the usage flow, so that more of what you do to collect and interact with people using your device ends up in the Facebook realm.  The more you use it, the more 'sticky' it is," he says.
And the result will be a huge and sustained flow of information to Facebook, which helps the company. "In the end," Morgan notes, "they are serving us ads."

A Brighter Way to Make Solar Cells

A Brighter Way to Make Solar Cells

A manufacturing method that uses light instead of heat wastes less energy and makes the cells more efficient.

Bright idea: This furnace uses lightbulbs, not heating elements, to treat silicon wafers.
Credit: NREL/Dennis Schroeder

Making solar cells involves subjecting silicon wafers to temperatures in excess of 1,000 °C. The process normally involves the use of heating elements, and requires a lot of energy.
A new optical furnace developed by researchers at the National Renewable Energy Laboratory in Golden, Colorado, heats up solar wafers by focusing light on them—a much more efficient process that uses about half the energy of a conventional furnace. More importantly, the new design also uses light to remove certain impurities from the silicon wafers, a step that can improve the power output of finished cells.
The work is at an early stage—so far the researchers have only improved the efficiency of the resulting solar cells by half a percentage point. But based on lab tests, they think they can increase the efficiency by four percentage points, from about 16 percent efficient to 20 percent, which would be a big deal in the solar industry, which celebrates even half-a-percent increases.
High temperatures are needed at more than one step during solar-cell manufacturing. Furnaces are used to introduce dopants into the silicon to create electric fields within the material, to create electrical contacts, and to oxidize surfaces to improve efficiency. The new furnace also allows for better control of some of these processes, which can improve a solar cell's efficiency.
NREL's design isn't the only one that uses light to process silicon. Rapid thermal processing furnaces, used in the microelectronics industry, also use light to heat up semiconductors. But the new furnaces use highly reflective and heat-resistant ceramics to ensure that the light is absorbed only by a silicon wafer, not by the walls inside the furnace. "That makes it many times more efficient," says Bhushan Sopori, the researcher in charge of the furnace project at NREL.

By precisely designing the shape of the interior of the furnace, the researchers can control exactly where the light is focused, ensuring the wafers are heated evenly. It's not enough to make sure the wafer is evenly illuminated—the edges have to receive more light because they lose heat more rapidly than the rest of the wafer.
The process reduces thermal stress on the wafers, and it allows for precise control over the chemical reactions that heating enables. Precise control of the rates and timing of the heating can also improve the electrical contacts on the solar cell, improving its efficiency. And it makes it practical to introduce an oxidation step. Oxidation has typically been used by only a few manufacturers for high-end solar cells, but the new process would make it cheaper and thus allow more manufacturers to use it.
Sopori says NREL has developed processes that take better advantage of photonic effects than the rapid thermal processing furnaces. As photons interact with the silicon, they can cause deleterious impurities such as iron to move out of the material, while keeping advantageous ones such as boron, which is needed for the solar cell to perform properly.
The researchers haven't yet realized the complete four percentage point improvement in efficiency in part because the new processing steps aren't all compatible with other steps in conventional manufacturing. Sopori says they are working to modify the other steps to take full advantage of the optical furnace.
NREL is also working with Advanced Optical Systems to develop a machine that can process not just one wafer at a time, as with the lab version, but up to 2,000. Such high throughput will be necessary if the furnaces are to compete with conventional ones, which are cheap to operate.

Eye Ball

Eye Ball

A globe studded with cameras captures a panorama if you throw it in the air.

• January/February 2012
• By Stephen Cass

If you toss this foam-covered ball skyward, an accelerometer inside determines when it has reached its maximum height. At that moment, 36 cameras are triggered simultaneously, creating a mosaic that can be downloaded and viewed on a computer as one spherical panoramic image. The ball was created by researchers at the Technische Universität Berlin after one of them, Jonas Pfeil, labored to create panoramas while on vacation in Tonga. On that trip, he tried a cumbersome process that required snapping pictures in different directions and stitching them together later in a photo-editing program. Now he hopes to license the camera-ball technology for commercial production.
A. Outer Shell
The sphere, about the size of a softball, is protected by blocks of foam. Thirty-six cell-phone camera modules, each with a resolution of two megapixels, are set into the surface. Each module stores its portion of the mosaic until it is transferred to the ball's microcontroller.
B. Inner Shell
The prototype's inner shell, made from a strong yet somewhat flexible nylon material, gives the ball structural strength. The shell was made using a 3-D printing service.
C. Power Source
The ball's power source, a relatively heavy lithium-polymer battery, is secured in an inner cage to keep its center of gravity close to its geometric center so that it behaves predictably when thrown.
D. Microcontroller
A microcontroller uses data from an accelerometer to determine when to trigger the cameras. Then it stores the resulting mosaic of images. The prototype can store one mosaic, but it has a hardware slot for a memory card that could store additional panoramas.
E. Panorama
Images are uploaded to a personal computer via a USB connection. Software on the computer allows panoramas to be rotated or enlarged, and portions can be exported as 2-D images.

More Transparent Tracking—Why Is There No App for That?

More Transparent Tracking—Why Is There No App for That?

A call for smart-phone software that lets users see what data their gadgets are sending out.

Amid widespread concern over an obscure piece of smart-phone diagnostic software that some experts say could be used to collect and transmit sensitive information, a leading academic has called on the industry to give users a one-click way to see what their gadgets are actually doing.
"It would be good to have some form of auditing function built into our devices," says Jonathan Zittrain, Harvard Law School professor and cofounder of the Berkman Center for Internet and Society. "The auditing function can be implemented by Apple and by handset makers through Android. Make it part of the 'About' tab. And it would show with whom the phone has been communicating and the sorts of things it has been sending."
Zittrain raised the idea in an interview following a controversy over software developed by a small company called Carrier IQ. Installed on at least 140 million phones, the software is designed to operate in the background and send performance data from handsets to telecom carriers, allowing carriers to diagnose dropped calls and obtain other network information.
The company was thrown on the defensive recently when a security researcher, Trevor Eckhart, said the software collected more sensitive information including "geographical location of the device, the end user's pressing of keys on the device, [and] usage history of the device," and posted a video showing the software capturing the text of his text messages, Google search terms, and location information—even though he'd disabled his GPS.
Carrier IQ has taken issue with the dark implications of the researcher's report. It says the details of the implementation were up to handset makers and that its product didn't "record, store, or transmit" personal information. That stance has been backed up by some researchers who have nonetheless called for tighter control over what the software can do and—echoing Zittrain's proposal—for more visibility for end users.
Already, some members of Congress have gotten involved, with Senator Al Franken, of Minnesota, demanding from Carrier IQ a detailed accounting of what data was collected and who got it, including whether law enforcement ever sought or obtained permission to use the technology as a back door for surveillance. The company is slated to reply to those questions on December 14.

There is no easy way for users to disable or remove the tool, which runs behind the scenes regardless of what the user is doing on the phone. But some handset makers, including HTC, have said they are exploring whether to allow consumers to opt out of data collection by Carrier IQ. And a security company, Bitdefender, last weekend released an app that can detect whether Carrier IQ is running on a phone. Another company, Whisper Systems, already offers Android apps that can help keep track of what different apps are up to on a device.
Catalin Cosoi, head of online threats at Bitdefender, however, says that inserting the Carrier IQ auditing function would have to be done at the operating system level, to which application developers do not have access. It would require a tweak by Apple to its iOS operating system, or by handset makers and networks using Android and other operating systems.
Until that happens, Cosoi adds, users have one other way to check what their smart phones are sending out: they can connect the phone to a laptop or PC running a traffic-sniffing program, such as Wireshark. But this is a fairly technical procedure, not the kind of simple function that users have come to expect on their phones.
Carriers and handset makers, including Apple, didn't immediately return calls for comment on the transparency-app idea yesterday. AT&T replied to reiterate that it used Carrier IQ only for network maintenance, and it did not address questions about whether it might give customers a way to audit data dispatches.
On the specifics of Carrier IQ, Zittrain says it is too soon to say how serious the matter might be. "It seems like there are competing empirical claims about what the software is doing," he says. And until more is known, he says, it is not particularly useful to focus on what the software has the potential to do. "You could say any application or process on a traditional PC has the potential to wipe your hard drive or monitor its bits, too," he notes.
But an easy-to-use auditing window would resolve the problem and prevent future controversies. "Why shouldn't we know what our phones are up to?" says Zittrain.

You Press the Button. Kodak Used to Do the Rest.

You Press the Button. Kodak Used to Do the Rest.

Kodak saw the shift from analog to digital photography coming. Here's why it couldn't win.

When I photographed Eastman Kodak's shuttered and vandalized film processing center outside of Stockholm a few years ago, it became clear to me that I held the very cause of all this destruction in my own hands: a digital camera.
Kodak held a monopoly position in the photographic-film industry throughout most of the 20th century. At its peak, the company employed more than 140,000 people, and its logo could be seen at every tourist attraction. In its hometown of Rochester, New York, the company was referred to as "The Great Yellow Father." A job at Kodak was considered a job for life. In 1997, the stock market valued the company at over $30 billion.
Today Kodak is worth only $265 million. As rumors abound about a looming bankruptcy, the story we hear is that it failed to see the shift to digital photography, and management incompetence sped its decline. A closer look, however, reveals a different picture: Kodak not only recognized the coming shift to digital photography but was also in many ways a pioneer.

Source: PMA

How is it possible for a company to have seen a technological discontinuity yet still end up on the brink of bankruptcy? To understand what at first appears to be a paradox, think back to Kodak's famous slogan "You press the button, we do the rest."
Kodak always sold cameras, but its real business was "doing the rest" – supplying and processing film. During Kodak's decades of dominance, the company built a vast and specialized infrastructure of machines, equipment, and skills in manufacturing, R&D, and distribution for film and photographic paper. With huge economies of scale and skills that were hard to replicate, barriers to entering the film business were very high. Competitor Fujifilm began to increase its global presence in the 1950s, but it took several more decades before the Japanese company became a serious threat to Kodak.
The large and complex process of operating a film business required a high degree of vertical integration. Kodak owned most parts of the supply chain; needless to say, control over basic research, raw materials, and film finishing further increased barriers to entry. The company had low production costs and few competitors, and back then people had no choice but to buy film in order to take photos. Kodak enjoyed tremendously high gross profit margins. Each "Kodak moment" was money in the bank.

First in class: Kodak created new a consumer market for photography with packaged film and inexpensive cameras like the $1 Brownie (shown), first introduced in 1900. Credit: Kodak

Kodak also invested extensively in research and development. In fact, the first electronic camera using a charge-coupled device was invented by a Kodak engineer named Steven Sasson in 1975, and Kodak in many ways led early development in digital photography. The company introduced the first megapixel sensor in 1986, and the QuickTake camera launched by Apple in 1994 had to a large extent been developed by Kodak. It looked like a pair of binoculars, stored 32 photos, and could be connected to a personal computer.
But the limited performance and the high price tag of such cameras (the QuickTake cost about $800 and a high-end digital news camera ran $15,000) meant that the market for digital photography was very small, almost insignificant for a multibillion-dollar company like Kodak. It is often difficult for large firms to bother with small markets and small profits, but Kodak nevertheless made these efforts in the 1990s.
In the meantime, Kodak's previously stable and solid film business became increasingly vulnerable. Fujifilm kept gaining market share, and in the mid-1990s a price war between Kodak and Fuji broke out in the United States. Eventually, Kodak had to lower prices. When George Fisher became CEO in 1993, he faced the challenge of fixing the core film business while at the same time preparing Kodak for the shift to digital photography.

Source: PMA

Fisher and most of his top management realized that digital imaging would displace film in the near future and that the company had to make dramatic efforts to transform itself. In a speech to the Academy of Management in Boston 1997, he said, "We are not in the photographic-film business or in the electronics business; we are in the picture business." Seeking to ride out the technological shift, Kodak kept launching better and better digital cameras, pushed its way into digital printing, and began laying off thousands of workers.
But the industry landscape was completely different in the digital era. Barriers to entry were significantly lowered and the industry was flooded by entrants with a background in consumer electronics, such as Casio, Samsung, and Hewlett-Packard, not to mention Japanese camera manufacturers including Canon, Nikon, and Olympus. Large parts of Kodak's competence base related to chemistry and film manufacturing were rendered obsolete. The vertical integration that had previously been a core asset to Kodak lost its value. Digital cameras became a commodity business with low margins. The problem facing Kodak wasn't just that film profits had died but that those revenues could not be replaced.
Once images became digital, Kodak's business model of "doing the rest" was effectively destroyed. Doing the rest used to entail a large and complex process that only a couple of companies in the world could master. Today, it is done by the click of a button.
Christian Sandström is a PhD researcher at the Ratio Institute in Stockholm and at the KTH Royal Institute of Technology.

 

Movies, Music, and More Move Inside Facebook

Friend me: Mark Zuckerberg announces new Facebook features at the company's F8 event.
Credit: Technology Review 

Computing

Movies, Music, and More Move Inside Facebook

Mark Zuckerberg announces ways to listen to music and watch movies inside Facebook, giving users less reason to spend time outside the site.

New features coming to Facebook this week will let users listen to music, watch movies, and read news without ever leaving the social network's borders. They will also automatically broadcast what users are listening to, watching, and reading, if the user gives permission. The changes, part of an attempt to encourage people to share more of their lives through Facebook, were announced by company founder Mark Zuckerberg at the company's F8 event in San Francisco today.

Zuckerberg announced during his keynote speech that a slew of media companies will collaborate on the project. If a person installs a Facebook app from any of those companies, his or her activity will be shown to friends via a new "ticker" box at the right-hand side of all Facebook pages. Users will be able to click on updates to get access to the same content, which will play, or become viewable, inside Facebook.

"You're going to discover lots of new things that your friends are already doing all the time right now," said Zuckerberg. "If I see that my friend is listening to something, I can hover over it and just play it; I'm listening with my friend, and my music is synched up with theirs."

A similar change will make it possible to watch TV shows or movies that friends are watching through services including Hulu and Netflix. Updates will be sent to Facebook even if a person is using a mobile app or watching through the service's own website. "We think this is going to make it so people can express an order of magnitude more than they can today," said Zuckerberg.

Zuckerberg's keynote was his first major public appearance since the launch of Google's competing social network, Google+, and the release of the Oscar-winning movie The Social Network, which painted him in a less-than-flattering light.

Saturday Night Live comedian Andy Samberg opened the proceedings, taking the stage in character as his comic version of Zuckerberg. Samberg announced a number of spoof Facebook features, including the "slow poke," before the real Mark Zuckerberg ran on stage for a few minutes of banter.

Zuckerberg's presentation was less well rehearsed than a Steve Jobs keynote, but he came across as more accessible than Apple's ex-CEO.

The new features may prove controversial. In some ways they resemble Beacon, a failed project from 2007 in which sites like Amazon automatically posted updates to Facebook when a person bought something. Beacon was cancelled after public protests over a lack of privacy controls.

Zuckerberg didn't mention Beacon, but privacy issues came up when Netflix CEO Reed Hastings took the stage to demonstrate how people will be able to use his service through Facebook. Hastings explained that the feature couldn't yet launch in the United States because of a decades-old law intended to prevent video rental stores from sharing titles rented by their customers, but he expressed hope that a bill currently before Congress would soon alter that law.

Facebook will compile a stream of snippets about a person's listening, viewing, and reading habits into summaries that their friends can read. "Sometimes you discover things your friends are doing right now; other times you want to look at patterns that build up over a period of time," said Zuckerberg. He added that the new features should make Facebook a driving force in making content, particularly music, pay in the digital era.

"The key to making music work [online] is not trying to block you from sharing songs you've bought; it's helping you discover music so you'll buy more," Zuckerberg said before introducing Daniel Ek, CEO of the music service Spotify, who claimed that data from his company's users showed that helping people sample songs makes them "twice as likely" to buy music.

Referring to Netflix, Spotify, and other partner companies planning to integrate with Facebook's new features, Zuckerberg said, "These companies are not just coming up with ways to make movies and TV more social; they're rethinking entire industries." The Web's most-read news source, Yahoo, is also working with Facebook, and News Corp.'s iPad-only magazine, The Daily, will become available through the site.

The new features are made possible by technology called the Open Graph, which connects Facebook's data with outside sources of information. First announced in 2010, the Open Graph made it possible for users to recommend books, movies, and Web pages via the now-ubiquitous Like button and have those recommendations appear on their Facebook page. The Open Graph can also describe people's connection to something—for example, showing that they "read," "watched," or "cooked" it. This kind of connection underpins Facebook's new features.

When the Open Graph project was first announced, it was pitched as way to allow users' social connections to follow them around the wider Web. The features announced today work in the other direction, bringing activity and content inside Facebook and potentially obviating the need to spend online time outside it.

Another new feature, dubbed Timeline, allows users to curate an interactive record of their life over the years. Timeline automatically summarizes a person's past Facebook activity and attempts to identify the most significant moments. Users can also specify particular photos, events, or other content to highlight on the timeline.

Search engine optimization

Search engine optimization (SEO) is the process of improving the visibility of a website or a web page in search engines via the "natural" or un-paid ("organic" or "algorithmic") search results. In general, the earlier (or higher on the page), and more frequently a site appears in the search results list, the more visitors it will receive from the search engine's users. SEO may target different kinds of search, including image search, local search, video search, academic search,news search and industry-specific vertical search engines.
As an Internet marketing strategy, SEO considers how search engines work, what people search for, the actual search terms typed into search engines and which search engines are preferred by their targeted audience. Optimizing a website may involve editing its content and HTML and associated coding to both increase its relevance to specific keywords and to remove barriers to the indexing activities of search engines. Promoting a site to increase the number of backlinks, or inbound links, is another SEO tactic.
The acronym "SEOs" can refer to "search engine optimizers," a term adopted by an industry of consultants who carry out optimization projects on behalf of clients, and by employees who perform SEO services in-house. Search engine optimizers may offer SEO as a stand-alone service or as a part of a broader marketing campaign. Because effective SEO may require changes to the HTML source code of a site and site content, SEO tactics may be incorporated into website development and design. The term "search engine friendly" may be used to describe website designs, menus, content management systems, images, videos, shopping carts, and other elements that have been optimized for the purpose of search engine exposure.
Another class of techniques, known as black hat SEO, search engine poisoning, or spamdexing, uses methods such as link farms, keyword stuffing and article spinning that degrade both the relevance of search results and the quality of user-experience with search engines. Search engines look for sites that employ these techniques in order to remove them from their indices.

Contents 1 History 2 Relationship with search engines 3 Methods 3.1 Getting indexed 3.2 Preventing crawling 3.3 Increasing prominence 4 White hat versus black hat 5 As a marketing strategy 6 International markets 7 Legal precedents 8 See also 9 Notes 10 External links

History

Webmasters and content providers began optimizing sites for search engines in the mid-1990s, as the first search engines were cataloging the early Web. Initially, all webmasters needed to do was submit the address of a page, or URL, to the various engines which would send a "spider" to "crawl" that page, extract links to other pages from it, and return information found on the page to be indexed.The process involves a search engine spider downloading a page and storing it on the search engine's own server, where a second program, known as an indexer, extracts various information about the page, such as the words it contains and where these are located, as well as any weight for specific words, and all links the page contains, which are then placed into a scheduler for crawling at a later date.
Site owners started to recognize the value of having their sites highly ranked and visible in search engine results, creating an opportunity for both white hat and black hat SEO practitioners. According to industry analyst Danny Sullivan, the phrase "search engine optimization" probably came into use in 1997.The first documented use of the term Search Engine Optimization was John Audette and his company Multimedia Marketing Group as documented by a web page from the MMG site from August, 1997.
Early versions of search algorithms relied on webmaster-provided information such as the keyword meta tag, or index files in engines like ALIWEB. Meta tags provide a guide to each page's content. Using meta data to index pages was found to be less than reliable, however, because the webmaster's choice of keywords in the meta tag could potentially be an inaccurate representation of the site's actual content. Inaccurate, incomplete, and inconsistent data in meta tags could and did cause pages to rank for irrelevant searches.Web content providers also manipulated a number of attributes within the HTML source of a page in an attempt to rank well in search engines.
By relying so much on factors such as keyword density which were exclusively within a webmaster's control, early search engines suffered from abuse and ranking manipulation. To provide better results to their users, search engines had to adapt to ensure their results pages showed the most relevant search results, rather than unrelated pages stuffed with numerous keywords by unscrupulous webmasters. Since the success and popularity of a search engine is determined by its ability to produce the most relevant results to any given search, allowing those results to be false would turn users to find other search sources. Search engines responded by developing more complex ranking algorithms, taking into account additional factors that were more difficult for webmasters to manipulate.
Graduate students at Stanford University, Larry Page and Sergey Brin, developed "backrub," a search engine that relied on a mathematical algorithm to rate the prominence of web pages. The number calculated by the algorithm, PageRank, is a function of the quantity and strength of inbound links.PageRank estimates the likelihood that a given page will be reached by a web user who randomly surfs the web, and follows links from one page to another. In effect, this means that some links are stronger than others, as a higher PageRank page is more likely to be reached by the random surfer.
Page and Brin founded Google in 1998. Google attracted a loyal following among the growing number of Internet users, who liked its simple design.Off-page factors (such as PageRank and hyperlink analysis) were considered as well as on-page factors (such as keyword frequency, meta tags, headings, links and site structure) to enable Google to avoid the kind of manipulation seen in search engines that only considered on-page factors for their rankings. Although PageRank was more difficult to game, webmasters had already developed link building tools and schemes to influence the Inktomi search engine, and these methods proved similarly applicable to gaming PageRank. Many sites focused on exchanging, buying, and selling links, often on a massive scale. Some of these schemes, or link farms, involved the creation of thousands of sites for the sole purpose of link spamming.
By 2004, search engines had incorporated a wide range of undisclosed factors in their ranking algorithms to reduce the impact of link manipulation. Google says it ranks sites using more than 200 different signals.The leading search engines, Google, Bing, and Yahoo, do not disclose the algorithms they use to rank pages. Notable SEO service providers, such as Rand Fishkin, Barry Schwartz, Aaron Wall and Jill Whalen, have studied different approaches to search engine optimization, and have published their opinions in online forums and blogs.SEO practitioners may also study patents held by various search engines to gain insight into the algorithms.
In 2005 Google began personalizing search results for each user. Depending on their history of previous searches, Google crafted results for logged in users.In 2008, Bruce Clay said that "ranking is dead" because of personalized search. It would become meaningless to discuss how a website ranked, because its rank would potentially be different for each user and each search.
In 2007 Google announced a campaign against paid links that transfer PageRank.On June 15, 2009, Google disclosed that they had taken measures to mitigate the effects of PageRank sculpting by use of the nofollow attribute on links. Matt Cutts, a well-known software engineer at Google, announced that Google Bot would no longer treat nofollowed links in the same way, in order to prevent SEO service providers from using nofollow for PageRank sculpting.As a result of this change the usage of nofollow leads to evaporation of pagerank. In order to avoid the above, SEO engineers developed alternative techniques that replace nofollowed tags with obfuscated Javascript and thus permit PageRank sculpting. Additionally several solutions have been suggested that include the usage of iframes, Flash and Javascript.
In December 2009 Google announced it would be using the web search history of all its users in order to populate search results.
The Real-time-search was introduced in late 2009 in an attempt to make search results more timely and relevant. Historically site administrators have spent months or even years optimizing a website to increase search rankings. With the growth in popularity of social media sites and blogs the leading engines made changes to their algorithms to allow fresh content to rank quickly within the search results.

Relationship with search engines

Yahoo and Google offices

By 1997 search engines recognized that webmasters were making efforts to rank well in their search engines, and that some webmasters were even manipulating their rankings in search results by stuffing pages with excessive or irrelevant keywords. Early search engines, such as Altavista and Infoseek, adjusted their algorithms in an effort to prevent webmasters from manipulating rankings.
Due to the high marketing value of targeted search results, there is potential for an adversarial relationship between search engines and SEO service providers. In 2005, an annual conference, AIRWeb, Adversarial Information Retrieval on the Web, was created to discuss and minimize the damaging effects of aggressive web content providers.
Companies that employ overly aggressive techniques can get their client websites banned from the search results. In 2005, the Wall Street Journal reported on a company, Traffic Power, which allegedly used high-risk techniques and failed to disclose those risks to its clients.^[23] Wired magazine reported that the same company sued blogger and SEO Aaron Wall for writing about the ban.^[24] Google's Matt Cutts later confirmed that Google did in fact ban Traffic Power and some of its clients.^[25]
Some search engines have also reached out to the SEO industry, and are frequent sponsors and guests at SEO conferences, chats, and seminars. In fact, with the advent of paid inclusion, some search engines now have a vested interest in the health of the optimization community. Major search engines provide information and guidelines to help with site optimization.^[26][27][28] Google has a Sitemaps program^{[dead link][29]} to help webmasters learn if Google is having any problems indexing their website and also provides data on Google traffic to the website. Google guidelines are a list of suggested practices Google has provided as guidance to webmasters. Yahoo! Site Explorer provides a way for webmasters to submit URLs, determine how many pages are in the Yahoo! index and view link information.^[30] Bing Toolbox provides a way from webmasters to submit a sitemap and web feeds, allowing users to determine the crawl rate, and how many pages have been indexed by their search engine.

Methods

Main article: search engine optimization methods

Getting indexed

The leading search engines, such as Google, Bing and Yahoo!, use crawlers to find pages for their algorithmic search results. Pages that are linked from other search engine indexed pages do not need to be submitted because they are found automatically. Some search engines, notably Yahoo!, operate a paid submission service that guarantee crawling for either a set fee or cost per click.^[31] Such programs usually guarantee inclusion in the database, but do not guarantee specific ranking within the search results.^{[dead link][32]} Two major directories, the Yahoo Directory and the Open Directory Project both require manual submission and human editorial review.^[33] Google offers Google Webmaster Tools, for which an XML Sitemap feed can be created and submitted for free to ensure that all pages are found, especially pages that aren't discoverable by automatically following links.^[34]
Search engine crawlers may look at a number of different factors when crawling a site. Not every page is indexed by the search engines. Distance of pages from the root directory of a site may also be a factor in whether or not pages get crawled.^[35] Additionally, search engines sometimes have problems with crawling sites with certain kinds of graphic content, flash files, portable document format files, and dynamic content. ^[36]

Preventing crawling

Main article: Robots Exclusion Standard

To avoid undesirable content in the search indexes, webmasters can instruct spiders not to crawl certain files or directories through the standard robots.txt file in the root directory of the domain. Additionally, a page can be explicitly excluded from a search engine's database by using a meta tag specific to robots. When a search engine visits a site, the robots.txt located in the root directory is the first file crawled. The robots.txt file is then parsed, and will instruct the robot as to which pages are not to be crawled. As a search engine crawler may keep a cached copy of this file, it may on occasion crawl pages a webmaster does not wish crawled. Pages typically prevented from being crawled include login specific pages such as shopping carts and user-specific content such as search results from internal searches. In March 2007, Google warned webmasters that they should prevent indexing of internal search results because those pages are considered search spam.^[37]

Increasing prominence

A variety of methods can increase the prominence of a webpage within the search results. Cross linking between pages of the same website to provide more links to most important pages may improve its visibility.^[38] Writing content that includes frequently searched keyword phrase, so as to be relevant to a wide variety of search queries will tend to increase traffic.^[38] Updating content so as to keep search engines crawling back frequently can give additional weight to a site. Adding relevant keywords to a web page's meta data, including the title tag and meta description, will tend to improve the relevancy of a site's search listings, thus increasing traffic. URL normalization of web pages accessible via multiple urls, using the "canonical" meta tag^[39] or via 301 redirects can help make sure links to different versions of the url all count towards the page's link popularity score.

White hat versus black hat

Main article: White or black hat

SEO techniques are classified by some into two broad categories: techniques that search engines recommend as part of good design, and those techniques that search engines do not approve of and attempt to minimize the effect of, referred to as spamdexing. Some industry commentators classify these methods, and the practitioners who employ them, as either white hat SEO, or black hat SEO.^[40] White hats tend to produce results that last a long time, whereas black hats anticipate that their sites will eventually be banned once the search engines discover what they are doing.^[41]
An SEO tactic, technique or method is considered white hat if it conforms to the search engines' guidelines and involves no deception. As the search engine guidelines^{[26][27][28][42]} are not written as a series of rules or commandments, this is an important distinction to note. White hat SEO is not just about following guidelines, but is about ensuring that the content a search engine indexes and subsequently ranks is the same content a user will see.
White hat advice is generally summed up as creating content for users, not for search engines, and then making that content easily accessible to the spiders, rather than attempting to game the algorithm. White hat SEO is in many ways similar to web development that promotes accessibility,^[43] although the two are not identical.
White Hat SEO is merely effective marketing, making efforts to deliver quality content to an audience that has requested the quality content. Traditional marketing means have allowed this through transparency and exposure. A search engine's algorithm takes this into account, such as Google's PageRank.
Black hat SEO attempts to improve rankings in ways that are disapproved of by the search engines, or involve deception. One black hat technique uses text that is hidden, either as text colored similar to the background, in an invisible div, or positioned off screen. Another method gives a different page depending on whether the page is being requested by a human visitor or a search engine, a technique known as cloaking.
Search engines may penalize sites they discover using black hat methods, either by reducing their rankings or eliminating their listings from their databases altogether. Such penalties can be applied either automatically by the search engines' algorithms, or by a manual site review. One infamous example was the February 2006 Google removal of both BMW Germany and Ricoh Germany for use of deceptive practices.^[44] Both companies, however, quickly apologized, fixed the offending pages, and were restored to Google's list.^[45]
Additionally, many professionals in the SEO industry refer to "gray hat" tactics that may skirt the lines of black and white hat tactics. Numerous references to gray hat techniques have been published, and these usually constitute practices that are not strictly disapproved by search engines, but may go against the spirit of the regulations that search engines have laid out.

As a marketing strategy

SEO is not an appropriate strategy for every website, and other Internet marketing strategies can be more effective, depending on the site operator's goals.A successful Internet marketing campaign may also depend upon building high quality web pages to engage and persuade, setting up analytics programs to enable site owners to measure results, and improving a site's conversion rate.
SEO may generate an adequate return on investment. However, search engines are not paid for organic search traffic, their algorithms change, and there are no guarantees of continued referrals. Due to this lack of guarantees and certainty, a business that relies heavily on search engine traffic can suffer major losses if the search engines stop sending visitors.It is considered wise business practice for website operators to liberate themselves from dependence on search engine traffic.A top-ranked SEO blog Seomoz.org has suggested, "Search marketers, in a twist of irony, receive a very small share of their traffic from search engines." Instead, their main sources of traffic are links from other websites.

International markets

Optimization techniques are highly tuned to the dominant search engines in the target market. The search engines' market shares vary from market to market, as does competition. In 2003, Danny Sullivan stated that Google represented about 75% of all searches.In markets outside the United States, Google's share is often larger, and Google remains the dominant search engine worldwide as of 2007.As of 2006, Google had an 85-90% market share in Germany.While there were hundreds of SEO firms in the US at that time, there were only about five in Germany.As of June 2008, the marketshare of Google in the UK was close to 90% according to Hitwise.That market share is achieved in a number of countries.
As of 2009, there are only a few large markets where Google is not the leading search engine. In most cases, when Google is not leading in a given market, it is lagging behind a local player. The most notable markets where this is the case are China, Japan, South Korea, Russia and the Czech Republic where respectively Baidu, Yahoo! Japan, Naver, Yandex and Seznam are market leaders.
Successful search optimization for international markets may require professional translation of web pages, registration of a domain name with a top level domain in the target market, and web hosting that provides a local IP address. Otherwise, the fundamental elements of search optimization are essentially the same, regardless of language.

Legal precedents

On October 17, 2002, SearchKing filed suit in the United States District Court, Western District of Oklahoma, against the search engine Google. SearchKing's claim was that Google's tactics to prevent spamdexing constituted a tortious interference with contractual relations. On May 27, 2003, the court granted Google's motion to dismiss the complaint because SearchKing "failed to state a claim upon which relief may be granted."
In March 2006, KinderStart filed a lawsuit against Google over search engine rankings. Kinderstart's website was removed from Google's index prior to the lawsuit and the amount of traffic to the site dropped by 70%. On March 16, 2007 the United States District Court for the Northern District of California (San Jose Division) dismissed KinderStart's complaint without leave to amend, and partially granted Google's motion for Rule 11 sanctions against KinderStart's attorney, requiring him to pay part of Google's legal expenses^.