Hey. For covering this assessment, I'd recommend firstly engaging with the text and deciding your own position (Try to show evidence of your engaging with the text..), whether you believe King Lear is ultimately redemptive or pessimistic. (Personally, I see elements of both, although I believe the play was more 'redemptive' in the original context than the present interpretation..)
From there, try browsing through the text (Particularly Act Five) to see how your position can be textually supported, whether through characterization or language. For instance, if your conclusion is 'redemptive', use Edmund and Edgar's reconcillation as evidence,
Some good I mean to do, Despite of mine own nature,
(Act V, Scene III, Lines 243-44.) , or the fact that order is ultimately restored to a single ruler.
This is simultaneously made less and more difficult by the fact that there is much 'evidence' to support either position. (And even the same evidence can be used eitherway. Many characters die in the final scene,
but the treatment of 'good' and 'bad' characters, particularly Cordelia and Goneril/Regan differ, and the survivors at the very end, Edgar, Kent and Albany are generally virtuous.
)
Seeing the audience is 'academic', it is advised to incorporate some literary criticism into your lecture. Quote influential critics who support your position as to Lear.. Fortunately, due to the vast quantity of Lear criticism, quotes can be found to support either position.
Examples include;
"King Lear makes a tragic mockery of all eschatologies; of the heaven promised on Earth, and the heaven promised after death,,Orders of established values of established values disintegrate. All that remains at the end of this gigantic pantomine is the earth, empty and bleeding [Jan Kott, 'King Lear Or Endgame?", 1965, published in 'Shakespeare Our Contemporary', ]
The play is not..pessimistic and pagan; it is rather an attempt to provide an answer to the undermining of traditional ideas by the new philosophy that called all in doubt [Kenneth Muir]
Many more can be found through research, although only a smattering would be necessary.
Also interesting is how the text's values have changed with time, influenced by interpretations, such as the nilhilistic Peter Brook adaption. (If you need details on how this effect is achieved, just ask.) I'd suggest also covering this element, if possible.
In short, perhaps it would be worth beginning by referring to Lear's textual ambiguity, but then emphasise that your position (for the lecture) is on the balance of 'evidence' corroborated.
In the body, outline your position using the text, critical viewpoints, and interpretations.. Whilst remembering to include elements such as values, ie;What values are suggested by the text's conclusion? (
Speak what you feel, not what you ought to say...Honesty.) In the conclusion, reiterate your position, and try concluding with a memorable statement if possible.
Ultimately, there is no single right or wrong position, and this is one reason I like King Lear so much. Interpretation is truly in the eye of the responder, and without a definitive meaning, it is ever-changing and therefore emminently adaptable.
Hopefully that helps.