Prof. Keith S. Taber's site
Main glossary
Features of an analogous system that maps well on the the target system.
"Sometimes, a distinction is made between positive, negative and neutral aspects of an analogy. In the nucleus-brain comparison, a positive feature of the analogy would be how the signals from the nucleus can influence activity in the rest of the cell (akin to how signals from a brain influence activity elsewhere in the body). " (Taber, 2013, p.1380)
Features of an analogous system does not map sensibly onto the target system.
"Sometimes, a distinction is made between positive, negative and neutral aspects of an analogy. In the nucleus-brain comparison…there are negative aspects to the analogy (the brain uses electrical signals as well as chemical signals: the nucleus just the latter)." (Taber, 2013, p.1380)
an analogy used in teaching
"There are many teaching analogies which are in common use, such as considering the nucleus of a cell to be like the brain…, or the camera to be like the eye… or considering the change of direction of light when it moves between materials with different refractive indices to be akin to a vehicle or marching band passing from a tarmacadam surface to a gravelled area…" (Taber, 2013, p.1380)
An analogy is a comparison between two systems suggesting a parallel in how they are structured, e.g., conceptual structure (target structure) is like a web or net (analogues):
"The basis of analogy is an explicit comparison between two systems that share some level of structural similarity. Such analogies can be highly fruitful in science itself as well as in science learning…The process of analogy involves a mapping of features between the analogue and the target to demonstrate the structural similarities in the two systems" (Taber, 2013, p.1380)
An analogue is a second system compared with a first (the target system) when making an analogy
Example of use:
"Teaching then often involves finding analogues from students' own experience that can be used as conceptual hooks (sic) that can anchor (sic) new learning to something that is already understood" (Taber, 2013, p.1378)
A metaphor is a figure of speech where one thing is said to be another – e.g., the nucleus is the brains of the cell. The metaphor is intended as a implicit comparison (cf. an explicit comparison such as a simile or an analogy).
Metaphors are often used in science communication annd popularisation, as well as in science teaching.
Read examples of metaphors used in discussing/explaining science
(Year 11) the final compulsory year of the English school system (though youngsters are expected to enter further eduction or training if they leave school at the end of Y11) – for 15-16 year old students.
the idea that in chemistry certain words, formulae and equations can refer at both the macroscopic level and the submicroscopic level, which means they support shifts between these levels (explaining bench phenomena in terms of quanticles) – but shifts that stunts may not automatically follow
"Whilst this is a powerful tool, once again it means that the learner has to deal with ambiguity in our symbolic representation, and to draw upon context and background knowledge to interpret when the teaching is using the symbolic representation to stand for phenomena, and when it models the conjectured world of subatomic particles used in chemical explanations." (Taber, 2009, p.100)
The history conjecture is an alternative conception that an electron derives from, or 'belongs to' (sic, notice the anthropomorphism), a particular atom, and this somehow influences its later behaviour.
This is part of the very common 'molecular' alternative conceptual framework for ionic bonding.
Read about the molecular framework for ionic bonding
Read about the history conjecture
"The expert is aware that the electron's history has no significance, but a learner may well expect there to be a greater attraction between an atomic core and the bonding electron that 'belongs' to that atom…" (Taber, 2009, p.81)
The idea that chemistry, as an academic discipline, (and one with its own system of symbolic representations), has its own language
"The reader is invited to see chemistry students as similar to learners working in a second language, where they are expected to be both learning the language and using the language to understand substantive material simultaneously. This is considered more than a metaphor…" (Taber, 2009, p.78)
"Before they will be given credit for using the language in formal assessments, students must learn the allowed symbols and what they represent; and understand the grammar of the representational language;
and know enough chemistry to be able to compose 'true' statements in the language, to represent actual or feasible reactions." (Taber, 2009, p. 86)
"The symbolic language of chemistry is an intellectual achievement of great power: but like all such systems it is only of value to us once we are fully initiated so it can become a facilitator of quick and effective communication, rather than being an additional barrier to comprehension and understanding." (Taber, 2009, p.103)
(molecular level) explanatory ideas at the level of quanticles – molecules, ions, electrons etc. (cf. macroscopic level; symbolic level)
(molar level) at the level of what is observed at the lab. bench (cf. submicroscopic level; symbolic level)