The Catholic Encyclopedia does make it clear that the European invaders had some difficulty differentiating between the native peoples they encountered.

For company, he has made up stories and now, after years suffering from "the Time cancer", has considerable difficulty differentiating between fact and fiction.

There can be difficulty differentiating between internal intussusception and a normal rectal fold.

As evolved as people liked to believe the human race had become, the mind still had difficulty differentiating between actual reality and perceived reality.

The Limits of Expression Computer civil-libertarians like the Electronic Frontier Foundation counter that the police typically have difficulty differentiating between criminal schemes and constitutionally protected free speech.

I was merely pointing out that there seems to be two ends of a spectrum and that the police appear to have difficulty differentiating.

An individual with this trait (termed a fantasizer) may have difficulty differentiating between fantasy and reality and may experience hallucinations, as well as self-suggested psychosomatic symptoms.

A person who is field dependent (FD) has a hard time viewing an object and its context or background as different entities and has "more difficulties differentiating between relevant and irrelevant information compared with FI individuals."

It can easily be confused with retinal detachment by the non-expert observer and in difficult cases even the expert may have difficulty differentiating the two.

They were generally ultrasonic motion sensors that had difficulty differentiating between a fluttering curtain and a fearless burglar.