# Ohmic and non-ohmic conductors

What sort of materials are ohmic and what sort of materials are non-ohmic? I have tried looking around on the internet and have not found any clear way to differentiate between ohmic and non-ohmic materials based on their properties. Would I be correct in saying that metals are ohmic; where as semiconductors and non-metals are non-ohmic? (assuming that they are at a constant temperature).

Ohmic conductors follow $V = R I$. Anything that does not is non-Ohmic.