In Ohio, convictions for 1st, 2nd, 3rd, or 4th degree misdemeanors and any felony conviction will give you a criminal record.
CONVICTIONS FOR MINOR MISDEMEANORS (IE. PUBLIC INTOX, OPEN CONTAINER, POT POSSESION OF UNDER 100 GRAMS) DO NOT GIVE YOU A "CRIMINAL RECORD".
If you are convicted of a minor misdemeanor, you do not have to disclose that conviciton to an employer or graduate school. It's like a parking ticket. Only in rare circumstances would you want to expunge a minor misdemeanor (remember: minor misdemeanors do not give you a record in the first place). If you receive or think you will be receiving Federally subsidized student loan, you should expunge any minor misdemeanor pot possession conviction. New laws make you ineligible for these loans if you have any drug convictions!