The Split-attention Effect occurs when sources of information that are mutually dependent for comprehension are separated either spatially or temporally. For example, if you need both a diagram and written text to understand an instruction but these are given to you separately or at different times, you will find it much harder to digest and understand the information. Whereas if both the text and the image are integrated into one visual then this speeds up the process of comprehension and lightens the demands on your brain.
The Split-attention Effect is especially applicable to learning environments and techniques. Students who are given learning materials that combine all required information into one easy-to-read document will learn faster – and retain knowledge for longer – than those who have to take in the same information from multiple sources.
If you were trying to put together a flat-pack piece of furniture and they provided you with the diagrams on one piece of paper and all the instructions and text on a separate piece of paper so you had to keep moving your attention from one to the other to understand – it would be much harder to follow. Integrating the diagrams and related text into one document on which you can concentrate all your attention will give a much greater chance of understanding and success.
Equally, if you’re trying to sell something online and your customer requires 2 or 3 pieces of information from you in order to feel confident that they are making a correct purchase or decision on your site, then all this information needs to be presented clearly and in one location so that they don’t have to search for it themselves and risk having their attention taken elsewhere.