1) First, think of any event–a historical event, a natural event, or a personal event–and explain the origins of the causal sequence that produced the event: was the event caused by the power of human thoughts, feelings, emotions, or human will? God’s will? If so, this is an idealist interpretation. Or was the event produced by material facts, scientific laws that put matter in motion, legal force, biological effects, social organization, etc.? If so, this is a materialist interpretation. Make your argument.
(2) Next, make a second argument that tries to convince someone who interprets causal chains in the opposite way from you that they should adopt your way of looking at things. If you are arguing as a materialist, try to convince an idealist that they ought to determine causality the way you do (or vice versa if you are arguing as an idealist). You can debate the merits of materialism or idealism in purely abstract terms, but it is usually helpful to make your case by using concrete examples of events to make your point.
By events, I am referring to things like the water crisis in Flint, election results, the phenomenon of earthquakes in North Texas, the results of a UFC fight, etc. Examples of events might include: disasters, wars, diseases, presidential elections, revolutions, sporting events, particular crimes, etc.
You must complete both parts of the assignment. The point of the assignment is not just to express your opinions but to think through your own reasoning processes and the reasoning processes of people with whom you disagree.
Here is some further reading for those who want to tackle this question at a higher level.