According to Wikipedia's entry on the Berlin Circle, the terms logical empiricism and logical positivism are largely used interchangably. To wit:
The Berlin Circle had much in common with the Vienna Circle, but the philosophies of the circles differed on a few subjects, such as probability and conventionalism. Reichenbach insisted on calling his philosophy logical empiricism, to distinguish it from the logical positivism of the Vienna Circle. Few people today make the distinction, and the words are often used interchangeably.
Why did Reichenbach try to distinguish his positions, or those of the Berlin Circle from those of his Austrian counterparts? How has it come that most philosophers do not distinguish between the two outlooks?