Principles of Design: Interference Effects
A phenomenon in which mental processing is made slower and less accurate by competing mental process.
Human perception and cognition involve many different mental systems that parse and process information independently of one another. The outputs of these systems are communicated to working memory, where they are interpreted. When the outputs are identical, the process of interpretation occurs quickly and performance is optimal. Otherwise, interference occurs and additional processing is needed to resolve the conflict. The additional time required to resolve the conflict impacts performance.
Examples of interference effects include:
Stroop Interference - an irrelevant aspect of the stimulus triggers a mental process that interferes with processes involving a relevant aspect of the stimulus. For example, the time it takes to name the colour of words is greater when the meaning and colour of the words conflict.
Garner Interference - an irrelevant variation of stimulus triggers a process that interferes with processes involving a relevant aspect of the stimulus. For example, the time it takes to name the shapes is greater when they are presented next to shapes that change with each presentation.
Proactive Interference - existing memories interfere with learning. For example, error often made when learning a new language because people apply the grammar of their native language to the new language.
Retroactive Interference - learning interferes with existing memories. For example, learning a new phone number can interfere with phone numbers in your memory.
Design Tips For Interference Effects
Avoid designs that create conflicting mental processes.
Interference effects of perceptions, such as Stroop & Garner, result from conflicting coding combinations or from an interaction between closely positioned elements that visually interact with one another. For example, a red go button or two icons groups or blend because of the shape and proximity.
Minimize interference effects of learning, such as proactive and retroactive interference, by mixing the presentation of modes of instruction, employing advance organizers, and incorporating periods of rest every 30-45 minutes.