Having a 'point of difference' - terrible phrase, useful concept - can come in handy in the modern world.

He further suggested that a useful concept should concurrently consider the properties of plant, soil and meteorological conditions.

Before this paper, atoms were recognized as a useful concept, but physicists and chemists hotly debated whether atoms were real entities.

They have recently gathered much attention as a useful concept to uncover structural design principles of complex networks.

Research in this area indicates that locus of control has been a useful concept for researchers in cross-cultural psychology.