CS - Elements of computational thinking 2.1.1

What is represenational abstraction

removing uneccesary details from a complex problem, to represent the problem as only consisting of its key features.

data abstraction

Details of how data is processed and stored os hidden, as a result, programmers can make use of ADS such as queues. The highest level of abstraction is closest to the user, usually as a user interface.

abstraction by generalisation

involves grouping together similarities within a problem to identify what type of problme it is.

what is the advantages of abstraction

This enables for more fficient design during software development as programmers can focus on elements that are necessary. This reduces time and resources spent on the project, and prevents it from getting unneccesrily large.

Abstarction vs reality

Abstarction is a simpified version of reality. Entities are represented as real-life values that can be stored as values. attributes are an abstarction for the characteristics for the real world entities.

what is meant by thinking ahead

process of a programmer planning their code to ensure an efficient outcome through using caching/ pre-fetching.

what are pre-conditions

these are requirments whcih must be met before a program can run. by ensuring these conditions are met, subroutines are made more reusable.

What is an argument

values passed into the parameters of subroutines.

What is caching

process of storing instructions in cache memory after they have been used as they may be used agian. this saves time which would be needed to go to SS and retrieve it fomr there, common caching includes web caching which is when frequent web pages are stored in cache so that it can be loaded quickly and also freeing up bandwidth.

What is pre-fetching

when algorithms predict which instrcutions are likely to be soon fetched. these instrcutions are loaded into cache before they are fetched, therefopre less time is spent waiting for instrcutions to be loaded into Ram.

reusable program components

commonly used functions are packaged into libraries for reuse, teams working on lare projects can import these subroutines. these are more reliable as they have already been tested on. saves time, money and resources. they can be used in projects whichc can rduce development costs.

what is a procedure and what is the difference between a function.

this is a named block of code that has computational steps and must be called for it to run. A fuction is a procedure that returns one or more values and a procedure doesnt return any value.

what are the benefits of procedural programming

splitting code into smaller chunks allows easier debugging, it can be called many times, it can be saved into libraries. large development teams can develop subroutines concurrently

what are the disadvantages of procedural programming

it uses global variables which means that when acessing it, it can be hard to debug where its value has changed.

what is concureent processing

Concurrent processing refers to the execution of multiple tasks or processes at the same time. It is a computing paradigm that allows for efficient utalisation of resources and improved system performance. In concurrent processing, multiple tasks are executed concurrently, either simultaneously or in overlapping time intervals. e,g multithreading, parallel processing

what are the advantages of concurrent processing

number of tasks completed within a time frame increase therefore more efficient use of the processor,less time waiting for input therefore less hardware botlleknecking.

What are the disadvantages of concurent processing

it can take longer to complete when a large number of tasks are being processed. not all tasks are suitable to be broken up and performed concurrently.