Expert has effect expertise
Academic views
There are two academic approaches to the understanding and study of expertise. The first understands expertise as an emergent property of communities of practice. In this view expertise is socially constructed; tools for thinking and scripts for action are jointly constructed within social groups enabling that group jointly to define and acquire expertise in some domain.
In the second view, expertise is a characteristic of individuals and is a consequence of the human capacity for extensive adaptation to physical and social environments. Many accounts of the development of expertise emphasize that it comes about through long periods of deliberate practice. In many domains of expertise estimates of 10 years' experience deliberate practice are common. Recent research on expertise emphasizes the nurture side of the nature and nurture argument. Some factors not fitting the nature-nurture dichotomy are biological but not genetic, such as starting age, handedness, and season of birth.In the field of education there is a potential "expert blind spot" (see also Dunning–Kruger effect) in newly practicing educators who are experts in their content area. This is based on the "expert blind spot hypothesis" researched by Mitchell Nathan and Andrew Petrosino. Newly practicing educators with advanced subject-area expertise of an educational content area tend to use the formalities and analysis methods of their particular area of expertise as a major guiding factor of student instruction and knowledge development, rather than being guided by student learning and developmental needs that are prevalent among novice learners.
The blind spot metaphor refers to the physiological blind spot in human vision in which perceptions of surroundings and circumstances are strongly impacted by their expectations. Beginning practicing educators tend to overlook the importance of novice levels of prior knowledge and other factors involved in adjusting and adapting pedagogy for learner understanding. This expert blind spot is in part due to an assumption that novices’ cognitive schemata are less elaborate, interconnected, and accessible than experts’ and that their pedagogical reasoning skills are less well developed. Essential knowledge of subject matter for practicing educators consists of overlapping knowledge domains: subject matter knowledge and pedagogical content matter. Pedagogical content matter consists of an understanding of how to represent certain concepts in ways appropriate to the learner contexts, including abilities and interests. The expert blind spot is a pedagogical phenomenon that is typically overcome through educators’ experience with instructing learners over time.Skilled memory theory
The role of long-term memory in the skilled memory effect was first articulated by Chase and Simon in their classic studies of chess expertise. They asserted that organized patterns of information stored in long-term memory (chunks) mediated experts' rapid encoding and superior retention. Their study revealed that all subjects retrieved about the same number of chunks, but the size of the chunks varied with subjects' prior experience. Experts' chunks contained more individual pieces than those of novices. This research did not investigate how experts find, distinguish, and retrieve the right chunks from the vast number they hold without a lengthy search of long-term memory.
Skilled memory enables experts to rapidly encode, store, and retrieve information within the domain of their expertise and thereby circumvent the capacity limitations that typically constrain novice performance. For example, it explains experts' ability to recall large amounts of material displayed for only brief study intervals, provided that the material comes from their domain of expertise. When unfamiliar material (not from their domain of expertise) is presented to experts, their recall is no better than that of novices.
The first principle of skilled memory, the meaningful encoding principle, states that experts exploit prior knowledge to durably encode information needed to perform a familiar task successfully. Experts form more elaborate and accessible memory representations than novices. The elaborate semantic memory network creates meaningful memory codes that create multiple potential cues and avenues for retrieval.
The second principle, the retrieval structure principle states that experts develop memory mechanisms called retrieval structures to facilitate the retrieval of information stored in long-term memory. These mechanisms operate in a fashion consistent with the meaningful encoding principle to provide cues that can later be regenerated to retrieve the stored information efficiently without a lengthy search.
The third principle, the speed up principle states that long-term memory encoding and retrieval operations speed up with practice, so that their speed and accuracy approach the speed and accuracy of short-term memory storage and retrieval.
Examples of skilled memory research described in the Ericsson and Stasewski study include:
a waiter who can accurately remember up to 20 complete dinner orders in an actual restaurant setting by using mnemonic strategy, patterns, and spatial relations (position of the person ordering). At the time of recall all items of a category (e.g., all salad dressings, then all meat temperatures, then all steak types, then all starch type) would be recalled in clockwise for all customers.
a running enthusiast who grouped together short random sequences of digits and encoded the groups in terms of their meaning as running times, dates, and ages. He was thus able to recall over 84% of all digit groups presented in a session totaling 200–300 digits. His expertise was limited to digits; when a switch from digits to letters of the alphabet was made he exhibited no transfer—his memory span dropped back to about six consonants.
math enthusiasts who can in less than 25 seconds mentally solve 2 × 5 digit multiplication problems (e.g., 23 × 48,856) that have been presented orally by the researcher.Rhetoric
Scholars in rhetoric have also turned their attention to the concept of the expert. Considered an appeal to ethos or "the personal character of the speaker", established expertise allows a speaker to make statements regarding special topics of which the audience may be ignorant. In other words, the expert enjoys the deference of the audience's judgment and can appeal to authority where a non-expert cannot.
In The Rhetoric of Expertise, E. Johanna Hartelius defines two basic modes of expertise: autonomous and attributed expertise. While an autonomous expert can "possess expert knowledge without recognition from other people," attributed expertise is "a performance that may or may not indicate genuine knowledge." With these two categories, Hartelius isolates the rhetorical problems faced by experts: just as someone with autonomous expertise may not possess the skill to persuade people to hold their points of view, someone with merely attributed expertise may be persuasive but lack the actual knowledge pertaining to a given subject. The problem faced by audiences follows from the problem facing experts: when faced with competing claims of expertise, what resources do non-experts have to evaluate claims put before them?
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