Silled, Unskilled And Semiskilled

Any one have matrix criterias for each job like 1, 2. 3. 4. such as age education and others

Thank you Sir for your great advises, please note my case is as the following:
I have to interview more than 500 individules to clasify them in a construction jobs.
My question is are there any criterias that assist me to say X is skill job and Y is samiskill and so on.