In the book "The Programmer's Brain: What every programmer needs to know about cognition", three cognitive processes are laid out: the LTM (Long Term Memory), the STM (Short Term Memory), and the Working Memory (WM). The knowledge stored in LTM persist through time and are what we recall from the past. This knowledge store is usually bigger. The STM is used to handle incoming new information and is much smaller than LTM. It is generally considered to be able to store only 2 to 6 items at any moment, and is meant to facilitate the processing or calculation of information in the WM. The WM is essentially a processor or calculator that changes or processes incoming information.
When we read code, the incoming information will first go through a filter that is based on knowledge from the LTM, where information considered to be not important for processing is left out before storage in the STM. From the STM, information will sent to the WM to be processed for comprehension in different ways and to different degrees depending on the time available, before storage in the LTM. The storage in the LTM may be lossy depending on the way the information is comprehended and associated with other information and knowledge, as well as over a longer period of time due to lack of refreshing or recalling. Storage strength is therefore improved by repeated study, while retrieval strength is improved by recalling what we have studied. Repetition and recollection intervals should be spaced out and interleaved.
Code reading and comprehension can be faster based on a few factors, such as familiarity with the programming language, the presence of well chunked comments in the code, the presence of familiar design patterns in the structure of the code, the use of meaningful names for variables and class names and meaningful log messages in the code, and the quick use of iconic memory to visually capture the overall structure of the code. Essentially, we should write code well in order for others and our future self to read and comprehend it faster.
Flashcards will help with memory retention to improve familiarity with the syntax of the programming language. We should test our memory recall with the same set of flashcards once a month to improve our LTM storage. For complex code or programming concepts, elaboration of our memory network through repeated active thinking and reflecting on the information to build mental schemata and actively connect new knowledge to existing related memories will strengthen our LTM. This will mean recreating and improving the content of flashcards.
Besides lack of knowledge due to inadequate storage in our LTM, we can also suffer from a lack of processing power in the WM, and this is related to the lack of information due to the small size of our STM or due to insufficient information provided by the code, because in both instances, the WM will have more to process to clear what has overloaded our STM, or engage in conjectures and assumptions which will both occupy STM and take up WM processing space and time. The WM's capacity is also about 2 to 6 items at a time, which is known as the cognitive load. The WM can better process information when they have been divided efficiently into chunks. The cognitive load in our brain can be divided into 3 types: the intrinsic load due to the complexity of the problem, the extraneous load due to distractions external to the problem, and the germane load caused by the processing necessary to store our thoughts into LTM.
There are several ways to reduce cognitive load on the WM: refactoring or changing the internal structure of the code to reduce duplication or improve readability; replacing unfamiliar language constructs such as lambdas, list comprehensions or ternary operators; using code synonyms in flashcards; and creating a dependency graph by annotating complex and interconnected code, and/or creating a state table containing the intermediate values of variables in timed sequence to read code that is heavy on calculations, in order to understand the overall coherence of the program.
No comments:
Post a Comment