Early estimates of working-memory capacity relied on the digit-span task, which indicated that working memory capacity was about 7 chunks. We no longer think that working memory capacity is fixed at 7 items because:
A. The episodic buffer was added to the working memory model
B. What used to be thought of as a capacity limit, is really just an indication of proactive interference
C. The stimuli being tested seems to influences capacity limit: we can remember 7 digits, but only about 4 colored squares, and only about two shaded cubes.
D. It has been demonstrated that iconic memory has a much larger capacity