**2. Videos in declarative learning**

Television and video have been used in distance learning not long after the invention of the television since back in the 1930s [1]. Video, though not a new tool, did not gain momentum in learning until recent years. As the learning management systems of online education evolve to integrate more diversified media formats, the combined use of video and the internet has become a dominant element of online

### *The Roles of Video in Online Learning DOI: http://dx.doi.org/10.5772/intechopen.114245*

learning [4]. As a matter of fact, in learning declarative knowledge, being more flexible and accessible, video lectures can be more effective than traditional in-person teaching if done right. YouTube is becoming a big tutoring platform for many kids, and video is a big driving force for the widespread adoption of flipped and blended learning [5]. In a well-crafted blended online course, synchronous and asynchronous elements mutually complement one another, and video has significant applications in both asynchronous and synchronous online learning. An analytical study of lecture videos has demonstrated that repeated video viewing is associated with more advanced levels of cognitive skills and better learning outcomes, and instructional video is more beneficial for low performers [6].
