I'm a data scientist by trade, and am gearing up to study the impacts of behaviors on mood. It's a domain specific study. I'm well versed in the statistics, but I need to record data that can be entered by people on a daily basis that quantifies things like mood, mental and emotional state, and cognitive focus.
I'll be tracking actions such as, for example, "did the person drink coffee today", and correlating that with mood, mental, and emotional state, cognitive focus.
I'm trying to keep the set of survey questions as simple as possible (to hedge against missing data), but also capture the most expressive set of variables I can within the most simple framework possible.
I'm looking for a recommendation from people who study psychology on how to go about balancing simplicity against expressiveness of the survey to track mood, mental and emotional state, and cognitive focus.
Are there standard approaches to quantifying this kind of information that I should be aware of?