Before revision: What these examples all have in common is that on a weekly basis (say) a single numbers can be recorded for each factor and one would expect particular streams of energy consumption to correlate with them either singly or in a multi-variate model.
After revision: What these examples all have in common is that on a weekly basis (say) numerical values can be recorded for each factor and one would expect particular streams of energy consumption to correlate with them either singly or in a multi-variate model.