Elements in Working Memory
This knowledge base has argued that the limited resources of working memory mean that only a few elements of information may be attended to at any given time.
The previous section demonstrated that to-be-learned information which has a high level of element interactivity imposes a cognitive load over and above that imposed by the elements themselves, due to the need to attend also to the relationships between elements. Consequently, high element interactive material exacerbates the difficulties which result from working memory limitations.
All of this begs the question "what is an element?" The short answer is "that it depends". It depends on the schemas held by the person who is required to attend to some body of to-be-learned information because generally, elements are schemas. What is a single element consisting of a single schema for an expert may be several elements consisting of sub-schemas for a novice.
Consider again the contrast between statements of the type represented by 1. and 2. below.
1. hea cto egttch. edg sda 2. The dog chased the cat.
The first statement presents itself as a random sequence of letters and spaces. It is without meaning and consequently each letter and each space is a separate element which working memory needs to attend to.
In contrast, the second statement contains obvious meaning, but only to a person who is sufficiently skilled in reading English. Each cluster of letters forms a meaningful word, and the words combine to form a meaningful sentence. Here the number of elements for an expert reader, who knows a little about the behaviour of dogs and cats, may be as few as one. After all, it is a grammatically correct sentence, and it is well known that dogs do chase cats.
Schemas not only provide the ability to combine 'many elements' into a single element. They also have the capacity to incorporate the interactions between elements. This means that information which consists of several elements, all of which interact with one another and thus display high levels of element interactivity, may become embodied into a single schema.
For example, the word "STOP" will be interpreted by most people as a single symbol, especially in the context of a roadside sign. The “routine” response triggered from interpreting such a symbol while driving results in a complex series of hand and foot movements.
Another example will be a professional fiberglasser who holds a schema for 'mixing resin' which takes into account not only the ideal ratio of resin and catalyst that need to be mixed, but also, automatically, considers interacting factors such as the air temperature, air moisture, and purpose of the mixture. It is likely that a novice in this area would not even know that if environmental factors such as temperature and moisture are not taken into account, then the effect of the catalyst may be altered and a defective mixture may result.