Whats your Tech level?

Like Education I am still working on cracking the code on Tech level.

What I know so far is:

1. Your Sims Education plays a roll
2. You need to have a Community College in or near your Industrial Zone
3. You need to get your land value up in your Industrial Zone - Parks,Parks,Parks
4. Putting a College in or near your Industrial Zone will help

I  have the 3rd star with a college with NO upgrades...