Computer Science - 2.1 - Elements of computational thinking

what is abstraction

the process of separating ideas from reality - hiding unnecessary detail and showing details that are important in context

what is an example of abstraction? where is it used

icons. When designing software and interface, abstraction often uses symbols, legends, colour-coding and icons to accentuate real life feature

icons are a great example of abstraction they can be used to suggest a function or process in a simple, efficient way

what is the need for abstraction?

to remove some details and highlight others to improve clarity of what is trying to be conveyed

removal of less important things to highlight the more important things

think of an example of abstraction in file management

when saving a file, the details of where is it stored and how is the data represented is abstracted

the users only need to be able to create, open, move, save and delete files. they dont need to know how it all happens

how to abstraction

remove unimportant details, add in details, change details, highlight details

What do you need to determine when designing a new system

the inputs the system needs

the outputs the system should produce

first decide what your system needs to output - what is its goal

once you understand what your system does, backtrack and work out the inputs it will need to produce the desir

what are most systems designed to produce

an output

visual, audio, haptic feedback, data to be input into another process or system

what should you identify when writing a computer program

the inputs, processes and outputs of a problem

what is a precondition

conditions that already exist and could affect how a solution to a problem is created.

whenever trying to solve a problem, it is always good to ask if there are any preconditions that you must take into consideration.

What is caching

an example of thinking ahead in computer architecture

instruction/data retrieved from secondary storage and placed into main memory often remain there in case they are needed again. resulting in much faster retrieval times as they don’t need to be fetched from secondary storage which is much slower compared to primary storage

what is prefetching

prefetching involves data being requested from main memory by the processor before it is actually needed

for prefetching to work, algorithms need to be designed to predict that an instruction or piece of data will be required soon.

a good example of this is taking your wallet out before paying to reduce time spent at checkout