Andy Stanfield, director of the Center for Teaching and Learning Excellence at Florida Institute of Technology, is a proponent of using Mayer's Cognitive Theory of Multimedia Learning to improve instructional design.

This theory posits the following: 

• The brain processes auditory and visual information differently
• There are limits to how much auditory and visual information people can process
• People must be actively engaged in order to move knowledge from working memory to long-term memory

This theory has some very practical implications for online course design, Stanfield says. For example, according to this theory, auditory input goes directly into the auditory channel for processing. With written language, the visual symbols must go through the visual channel and be converted to the auditory channel, which creates an extra level of processing that could inhibit learning.

“So then, a lot of instructional design comes down to how you are going to use images, text, and narration so that you're getting the maximum efficiency from your auditory and visual channels,” Stanfield says.

The following are Stanfield's recommendations for achieving this efficiency: 

• Short, focused lessons—As an instructional designer, Stanfield has noticed a tendency for subject matter experts to try to incorporate too much content into their courses. “It took professors decades to learn this stuff, and oftentimes they want their students to know everything they know, but it's impossible.
  
  “Instructors should try to get the students the basic skills and then get them to have such a love of [the subject] that they want to make the effort to develop mastery of the subject. Telling students every little anecdote may be interesting, but is it effective? It may actually distract from the learning objectives,” Stanfield says.
  
  Rather than the traditional lecture, Stanfield advocates very detailed, short lessons that take into account the way the brain works. “If you're talking for an hour, there's a good chance you're going to be bringing in other things that are not specifically focused on the topic. If you have a shorter lesson, it's easier to make sure you're staying true to what you were at least nominally attempting to do.”
  
• Proper balance of text, image, and narration—Stanfield recommends reading Presentation Zen by Garr Reynolds to gain an understanding of how to present materials in ways that do not overwhelm students. He also recommends Haiku Deck, an iPad app that limits the number of words on a PowerPoint slide so that the emphasis is on the visual elements.
  
  The idea is to provide a minimal amount of text with just a few major bullet points to help learners keep the concepts in mind and conceptually linked images that enhance but don't distract. Narration should provide the majority of the information in a presentation, Stanfield says.
  
  If there is important presentation-related content that is text based, provide a handout. “Nothing bothers me more than when professors post to the learning management system a heavily text-based PowerPoint without narration. If you've got all this great text, copy it and put it in a Word document that students can have at their side so they can focus their limited working memory on the lecture itself—pictures, a few words [of text], and mostly voice,” Stanfield says.
  
  Related images and text should be in proximity to each other so that students won't have to overtax their working memory unnecessarily, Stanfield says. In addition, there can be some redundancy among the various elements of a presentation, but the narration should not be a verbatim reading of the text that appears on the slides, because visually processing text and converting it to the auditory channel takes more time than does processing auditory input, and this can overload working memory.
  
• Avoid distractions—Potential for distraction is also the reason Stanfield does not use social media in online courses. He says that social media content that is only tangentially related to the learning can easily lead learners astray. “That's a working memory issue, and it ties in with motivation,” Stanfield says.
  
  In addition to trying to include too much content in online courses, educators, particularly when using a new piece of software, have a tendency to use many of its features regardless of their educational value. To avoid this “kitchen-sink effect,” Stanfield recommends playing with the new software to get past the novelty of its interesting features before using it to create content for an actual course.
  
• Think like an instructional designer—“Stop thinking as a subject matter expert and start thinking as a designer. Try to remember what it was like not to be an expert. I think that, at a certain point, if you know something so well, you almost assume everyone else does. Sometimes you forget the struggles you had learning a particular concept. Oftentimes if you can step back from the subject matter expert role and think as an outside objective observer, a lot of these things take care of themselves,” Stanfield says.