Teach Computing

Revision notes, activities, lesson plans, teaching ideas, and other resources for GCSE, A-Level, and IB Computer Science teachers and students.

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Device specifications

Device Specifications is a simple site with a huge database of smart phones...

Smart phone specs explained

This excellent site is a detailed guide to smart phone specifications, expl...

Software as a Service (Saas)

This short video gives an overview of Software as a Service (SaaS), which s...

Amazon EC2 - Elastic Cloud Server

Amazon Elastic Cloud (Amazon EC) is a good example of Infrastructure as a S...

Changeover notes

IGCSE ICT provide short but clear notes and diagrams covering the different...

CommandPoint CAD

CommandPoint by Northrop Grumman offers a range of CAD systems for various ...

CAD+911 System

TriTech Software Systems is a company that specialises in Computer Aided Di...

London Ambulance CAD failure

The 1992 London Ambulance Service CAD failure is probably the most notoriou...

Washington State 911 Failure

A 911 emergency telephone system in Washington State and Oregon shut down f...

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1.1 Systems in Organisations

Click here for recommended IB Computer Science textbooks.

Planning and system installation

1.1.3 Compatibility issues

When implementing new systems there may be (in)compatibility issues with existing hardware or software. You need to be aware of the issues that can arise - especially in the international context, where language and number systems can be significantly different.

1.1.4 Local and remote hosting

This topic involves comparing systems hosted locally on a client computer with those hosted on a remote computer. This remote hosting could refer to Software as a Service (Saas) or Infrastructure as a Service (Iaas).

Software as a Service (Saas) video

Software as a Service (Saas)

This short video gives an overview of Software as a Service (SaaS), which should be a useful starting point for a discussion of the benefits and drawbacks compared to local hosting.
Updated: 2018-11-08
Amazon Elastic Cloud video

Amazon EC2 - Elastic Cloud Server

Amazon Elastic Cloud (Amazon EC) is a good example of Infrastructure as a Service (Iaas). This video clearly explains how processing power, memory, and disk storage can be "rented" from Amazon over the Internet, dynamically increasing and reducing resources as required.
Updated: 2018-11-08

1.1.5 Installation processes (Changeover processes)

For this topic you need to know the difference between the main ways of performing a changeover to a new system. The IB refers to these as "installation" processes and you might also hear them called "implementation" processes. The main ways are:

  • Direct changeover
  • Pilot changeover
  • Phased changeover
  • Parallel changeover

You should be aware of the advantages and disadvantages of each method.

Changeover

Changeover notes

IGCSE ICT provide short but clear notes and diagrams covering the different types of changeover.
Updated: 2018-11-08

1.1.6 Data migration

Data migration is the process of moving data from one (old) system to another (new) system. Various issues can occur depending on the file format, data structure, and other issues. Data migration is closely linked to 1.1.3 Compatibility issues, as the data may also be stored on old media (e.g. floppy disks, tapes, ZIP drives, etc).

Internationalization

Internationalization

This pair of videos from Computerphile explain some of the issues that arise when trying to create software for international audiences. The first, The Problem with Time & Timezones covers issues with global time calculations and some of the special cases which exist.

The second, Internationalis(z)ing Code, covers many issues relating to language - which go far, far beyond simple ASCII and Unicode character set issues.

The videos use multiple real life examples to highlight social and cultural differences across the globe, and how they affect programmers. They are implicitly address quite a few issues related to the IB TOK course.


Updated: 2015-05-25

1.1.7 Types of testing

You should understand the different types of testing (alpha testing, beta testing, user acceptance testing), and the debugging process. You should also be aware of the critical importance of testing and the consequences of insufficient testing. Finally, you should be aware that there are tools to automate parts of the testing process.

1.1.8 and 1.1.9 User documentation

1.10 User training

1.1.11 Causes of data loss

Data security

Examples of database security problems

The news articles below cover some of the major risks of malicious actions such as hacking or malware. Myriad examples of these problems exist (and new ones seem to appear every few weeks), but the examples below highlight some of the more famous cases (and the greatest losses).


Updated: 2015-04-18

1.1.12 Consequences of data loss

1.1.13 Preventing data loss

You should know about a variety of systems for preventing data loss. In addition to regular backup systems, these also include systems to prevent downtime, such as failover systems and redundant systems.

1.1.14 Managing releases and updates