For this blog post, I will discuss short-term memory and how it pertains to my previous experience in the military. While working in Afghanistan, I was constantly required to receive and report the specific grid coordinates of individuals or events. Depending on the length of the grid coordinates, they could be difficult to report accurately. The capacity and duration of short-term memory and the use of chunking to expand the capacity did have an effect on my job performance.
In lesson 5 of this course, we learned that George Miller discovered what he believed to be the capacity of short-term memory. This capacity was 7 +/- 2 items (Miller, 1956). This means that on average, one is able to memorize and recall 7 +/- 2 specific items at any given time. I do agree with this suggestion based on my own experience. The Military Grid Reference System (MGRS) uses a header for each location that denotes the general area in which to find the grid points. An example header would be 15P SU. Following the header, there would be a four-digit, six-digit, eight-digit, or ten-digit grid point, with the longer grid points being more accurate. Due to the capacity of short-term memory, the four-digit and six-digit grid points were usually simple to recall, and longer grid points did prove to be more difficult. While attempting to recall longer grid points, I often had to report half of the grid and reference the grid again before reporting the second half.
I also noticed that chunking was very helpful if the number sequences held any significance. For example, 15P SU 1776 2001 would be easier to recall than 15P SU 5476 8729. This is because 1776 and 2001 become only two separate items instead of eight separate items, but 5476 and 8729 are number sequences which hold no significance for me, so I would have to recall each number individually.
Furthermore, it has been suggested that short-term memory usually has a duration of 15-30 seconds. This means that even if a sequence of numbers is initially memorized, that memory may diminish over a very short period of time. I experienced this quite often as well. While it was simple to recall a memorized grid point during the few seconds that it took to report it over a message board on the computer, it was much more difficult to recall the same grid point only a minute or two later when attempting to report it over the radio or to the commander. Therefore, it was most efficient to document the grid points for future reference.
The use of short-term memory was constant during my military career, and knowing the limits of short-term memory can be crucial when dealing with important tasks, such as reporting accurate grid coordinates. Many experiments have been conducted in the past in order to study the capabilities and processes of memory in humans. After learning about the results of these studies and comparing them to personal experiences, I believe that they are relatively accurate, and I have gained a more thorough understanding of the cognitive processes involved with memory.
Miller, G. A. (1956). The magical number seven, plus or minus two: Some limits on our capacity for processing information. Psychological Review, 63(2), 81.