IT in society (A Level) flashcards

Topic 12: IT in society

Virtual currency vs cryptocurrency

A virtual currency is issued and controlled by its developers and used in one online community. A cryptocurrency is a virtual currency secured by cryptography and recorded on a decentralised ledger.

Centralised vs decentralised digital currencies

Centralised: one authority, such as a bank, checks transactions and keeps the record (debit and credit cards, EPOS). Decentralised: a network of peers checks them and every node holds a copy of the ledger (Bitcoin, Litecoin).

Describe how a blockchain works

Transactions are grouped into a block; the block stores the hash of the previous block; nodes agree the block is valid; it is added to every copy of the ledger. Editing an old block changes its hash and breaks the link.

What is data mining?

Using software to search large data sets for previously unknown patterns, relationships and anomalies, to make predictions and support decisions.

Name the six stages of data mining in order

Business understanding, data understanding, data preparation, data modelling, evaluation, deployment.

Instant messaging vs chat room

Instant messaging is real-time messaging with known contacts or small groups. A chat room is a real-time, topic-based space open to many users, often strangers.

Give two negative impacts of social networking on individuals

Any two of: intellectual isolation, effects on physical and mental health, ideological polarisation, stereotyping, cognitive issues.

MOOC vs networked course

A MOOC (massive open online course) is open to anyone at very large scale, with little individual support. A networked course is delivered to a closed group over one network.

Give one benefit and one drawback of surveillance by the police

Benefit: CCTV, number plate and facial recognition help detect crime. Drawback: mass surveillance reduces privacy and misidentification can occur.