High school teacher Maria Johnson isn't impressed by her students' Google and Wikipedia research.

By Sally Holland, CNN

Washington (CNN) – A new study from the Pew Research Center’s Internet and American Life Project found cell phones, tablets, Google and Wikipedia are at the center of how educators teach and how students learn – but they bring new challenges, too.

Almost three-quarters of teachers surveyed said cell phones are used in their classrooms to complete assignments, while 45% use e-readers and 43% use tablet computers.

Many teachers – 99% – themselves rely on online research, but they believe digital technologies make it harder for students to “find and use credible sources of information.”

The Pew study said 76% of teachers surveyed strongly agree that  “search engines have conditioned students to expect to be able to find information quickly and easily,” and 83% agree that the amount of information is overwhelming.

The survey of about 2,400 middle school and high school teachers from across the United States asked how they use technology in their classrooms and at home. The teachers were all Advanced Placement teachers or from the National Writing Project, so all their students are considered academically advanced.

“Several teachers noted that if a student looks for a particular piece of information online for a few minutes and can’t find it, they will often not interpret that to mean they have to search differently or go to a different resource,” said Kristen Purcell, the main author of the report.

Students will assume “that information is not out there to be found,” she said. “If it were, the search engine would find it quickly.”

When high school science teacher Maria Johnson assigns online research, she doesn’t want her students using popular sites like Google or Wikipedia. They can be helpful to find a quick definition, she said, but they’re too “noisy” – too much extraneous information, incorrect information and ads and pop-ups that distract students.

“For actual research, I think it’s best if I give them a list of sites to go to,” said Johnson, who teaches in Arlington, Virginia.

Purcell says the teachers don’t believe that sites with user-generated content, like Wikipedia, are inherently harmful, but rather “that students lack the ability to assess the quality of the information they find online.”

“Often students are looking for a site where they can go to the quickest and the most information with minimal effort,” said Julie Caccamise, a social studies teacher at Woodrow Wilson High School in Washington. “Sometimes they’re not interested in the difficult work, which is sorting through the information and deciding what is important and how valuable it is.”

Caccamise, who has taught for 18 years, used to be against students’ using Wikipedia because the information could be modified by anyone, making it unreliable. Now, she sees more value in the site. The citations at the end of entries can give students additional ideas about where to search.

“Often it offers an interesting starting point for students when they are doing research,” she said.

How is technology used in your classroom, or your child’s classroom? Is there any technology you don’t want students or teachers to use?