Look it up: Printed dictionaires are becoming a thing of the past.   Reuters/Ruben Sprich/Files

Look up the word “obsolete” in the dictionary and one might expect to find a picture of a dictionary. Most of us don’t think much anymore about how the digital revolution has changed our access to reference material. We simply take it as a given that Wikipedia and will be there for us when we need it.

But for publishing companies that had once cornered the market on such material -- Macmillan, Britannica, F+W Media and others -- the change has not been an easy one. This week, Macmillan Education, the British publishing giant of school and reference books, announced that its dictionaries will no longer be available in printed form. Rather they will exist exclusively online. The decision comes eight months after Encyclopedia Britannica announced that its storied volumes are going all-digital after 244 years.

The advantages to online reference material are obvious. Digital databases are updated constantly, as opposed to every few years. They are simple to search and easy to bookmark. They are also, in many cases, free -- a detail that has radically altered the economics for companies tasked with editing and updating high-quality material.

“We’re moving from a situation where there was a pretty straightforward business model -- I sell you a physical product, you give me money for it, this money supports further development -- to a situation which is, for now, much more uncertain,” said Michael Rundell, editor-in-chief of Macmillan Dictionaries. “Instead of a single income stream, we see a more fragmented picture.”

Rundell said one of the biggest changes for dictionary publishers is the move toward an advertiser-supported business model. The website for Macmillan Dictionaries is free for users, but it carries advertising that generates revenue based on traffic. The company has also delved into content licensing, app development and even grammar-oriented online games. Rundell admits that such changes come with a downside, but he sees the shift from print to digital as an “overwhelmingly positive” one for both the industry and for readers. “Digital media give us so many more opportunities to provide useful language content,” he said.

Jorge Cauz, president of Encyclopaedia Britannica in Chicago, added that reference publishers that want to remain relevant simply have no choice but to embrace pixels over paper. “The whole ecosystem of reading, writing, publishing and learning has migrated to digital platforms,” he said. “Whether we’re talking about newspapers, trade books, textbooks or magazines, it’s how people want to get information and knowledge.”

Britannica Online contains no advertising but instead offers paid premium content, a model Cauz admits is a challenge in the Web’s culture of free, where the anyone-can-edit Wikipedia routinely appears at the top of Google search results.

“There are a lot of challenges to making it work,” he said. “The key is to have a differentiated service that can attract a large digital audience and operations that adapt quickly to the rapidly evolving tastes and technical requirements of the new digital marketplace.”

Cauz also pointed out that, while encyclopedias and dictionaries have much in common, they have not been affected equally by the transition to digital platforms. He pointed to the still-ubiquitous presence of the dictionary published by Britannica’s sibling company, Merriam-Webster, whose reference books still enjoy a sizable amount of shelf space in bookstores. “Maybe because of their convenience and relatively low prices, demand for single-volume print dictionaries is strong here in the U.S.,” he said. “And it looks like that will continue for some time.”

In the meantime, for diehard print junkies on the other side of the Atlantic, there is still time to get your hands on a Macmillan dictionary. Rundell said that Macmillan has ensured that its final print run will be large enough to meet demand for “a while to come.”