What refers to the number of items a person can remember and repeat back using attention and short term memory?

Memory span refers to the ability of an individual to retain and accurately recall a sequence of items, typically measured by how many items can be remembered in a given task. This concept is often assessed through tasks where participants are required to repeat back a list of numbers, letters, or words immediately after presentation. The average memory span for most individuals is around seven items, also known as Miller's Law, which suggests that our short-term memory can hold about seven pieces of information at once.

In distinguishing this from the other options, chunking is a memory strategy that involves grouping individual pieces of information into larger, more manageable units, which can actually enhance effective memory span but is not the same as the span itself. Capacity limit refers more generally to the theoretical maximum number that a memory system can hold and isn't a specific measurement of immediate recall performance. Short-term retention relates to maintaining information over a brief period but does not specifically focus on the quantity of items recalled in immediate recall tasks. Thus, memory span accurately captures the concept of how many items can be actively processed and recalled in the context of attention and short-term memory.