|Click caption to listen to Tom Lehrer's 'Periodic Table Song'|
One of the lessons being learned with the new TOK Essay marking criteria is the need for a clear and explicit attempt at unpacking the key terms of the title. Usually, this should be done concisely and precisely in the introduction, alongside the presentation of a thesis that sets the direction of your essay. By all means, go to a dictionary and remind yourself of the meaning of words, but avoid reproducing them wholesale in your essays: it takes too much TIME and involves much word wasting on definitions which have little or nothing to do with TOK.
So here goes:
Explanations involve giving reasons for why you believe what you believe and can fall into two broad categories that tie in with the TOK definition of ‘knowledge’ as ‘justified true belief’.
First, evidential reasons in the form of objective, empirical evidence, data or statistics that help support or refute a specific knowledge claim. For example, the observational data generated by Tycho Brahe which helped Kepler formulate his mathematical calculations to explain elliptical orbits. Or, the preponderance of evidence gathered to refute the claim that the Bermuda triangle is a place in which weird, paranormal activities take place.
Second, non-evidential reasons in the form of subjective, personal testimony based on emotion, intuition or faith, which help or hinder the justification of our knowledge claims. For example, the intensely felt experience of the ever present force of Brahma is explained by Buddhists in terms of mindfulness, a form of intuition. Or, the ideals of terrorists, of whatever denomination, which are often grounded in extreme interpretations of sacred writings, a form of faith.
‘Prerequisite’ implies that there is a step by step order in the process of knowledge building, in which certain steps come before, first or are a basis for, or ground or foundation of other steps. Finally, in a basic sense ‘prediction’ means a best guess about the future; more specifically, it involves making specific claims about future conditions or events based on general laws or statements. At least, if you’re aiming to be objective and scientific! So yes, you can have predictions based on both empirical and non-empirical kinds of explanation; and yes, you can have predictions made on nothing resembling an explanation at all. It just depends on how reliable you want your predictions to be and how you KNOW this…
This should give you the KIND of thing you may do in your introduction. The direction of your essay will then focalise on two AOKs, one of which could be the Natural Sciences. Here’s an example many of you will no doubt explore: Henry Mosely and the periodic table…
Mendeelev invented the periodic table but the explanations for ordering them were largely based on their perceived chemical properties and a subjective, intuitive sense of their relative atomic masses. Mosely’s experiments provided a more objective, measurable basis for explaining why elements should be ordered in specific ways: the mathematical link between the protons in an element’s nucleus with that element’s atomic number.
Now, the strange thing is, both Mendeleev and Mosely were able to predict the existence of elements missing in their versions of the Periodic Table. While Mendeelev’s intuitive based prediction was that an element was missing from the table, Mosely’s more experimentally based prediction could actually pin point WHERE in the Periodic Table the gaps were…