The New England Primer, the most popular early printed book, was intended to make learning to read more interesting for children.
It took a while for educators to realize its effectiveness with whole group instruction, however.
Years of refinement and use in the business world preceded its introduction into education in the 1920s.
The technology was refined and developed further over the next decade, until educational films were first exhibited.
Again, it was a gradual introduction before they replaced individual slates for students
Instructional use of the radio picked up after the equipment prices dropped in the 1930s.
The instructional use of television reached its peak in the 1950s and 1960s.
Originally intended to individualize instruction, computers would not become a practical addition to K-12 schools until the late 1970s.
The Virtual High School (VHS) was launched in the late 1990s, and online courses as well as internet based activities and instruction followed.
Schools are just now beginning to introduce cloud storage as a method for sharing resources in the classroom.