How can I empirically and efficiently identify personality types, and judge how 'compatible' they are with myself?

Hello r/askacademia,

I am interested in studying people's personalities. It's hard for me to articulate what I'm looking for, so I will present to you several of my goals. I want to...

• Be able to efficiently and empirically identify a person's personality type. By "efficiently and empirically", I mean by observing someone's behavior over time. Psychological surveys/tests are nice, but they are not convenient.
• Take said personality information and compare it against my own to determine if their personality type would be compatible with mine, within the context of a potential romantic relationship.

Some additional food for thought which may help clarify my question:

• How do the eHarmony.com "metrics" work to judge and quantify personality compatibility?
• I have done some casual reading about Meyers-Briggs Type Indicators and Keirsey temperaments, but I do not know how to determine someone's personality type/temperament, and I do not know how to judge compatibility with my own type.
• Are there even studies which conclusively show that certain personality types are more compatible with others on a romantic relationship level?
• Essentially, I'm looking for a more structured approach to judging compatibility.

What do I study in order to be able to do this? I am out of school and will not be able to take any formal courses; so any internet or book resources you can provide would be appreciated. I've been poking around, hope I am posting this in the correct reddit. If I botched up any of the terminology; forgive me, I am most definitely not a psych major.