5.3 Summary

Common sense is a complex and contested phenomenon. The practice of systematic scepticism is a key aspect of social science, particularly in the analysis of common sense and the consideration of the social construction of social problems. Social constructionism emphasises the importance of social expectations in the analysis of taken-for-granted and apparently natural social processes. It starts by exploring the assumptions associated with the naming or labelling of things. It is sceptical ab
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Learning outcomes

After studying this unit you should be able to:

  • illustrate what is social about social science;

  • demonstrate how certain social constructions become dominant;

  • distinguish how labelling something can create expectations about behaviour and actions;

  • give examples of inequalities that result from particular social constructions.


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Digital communications
Optical-fibre communications became commercially viable in the 1970s and innovation continues today. This unit will illustrate how very high data rates can be transmitted over long distances through optical fibres. You will learn how these fibres are linked, examine the technology used and assess the future direction of this continually developing area of communication.Author(s): Creator not set

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Design thinking
Are you ever frustrated with something that you thought you could design better? Design thinking can structure your natural creativity to come up with solutions to all kinds of problems, and have fun in the process too! First published on Thu, 22 Dec 2011 as Author(s): Creator not set

2.1 Numbers

The supermarket example discussed in Section 1 involves various forms of data that a computer may need to handle. Some of these, such as numbers and characters, are simple but fundamental. Other forms of data, such as sequences, involve more complicated structure. In this section, we will introduce sets, which are a variety of data collection that is different from sequences. But first we will look more carefully at numbers and characters.

When developing software we need to dist
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Learning outcomes

After studying this unit you should be able to:

  • evaluate technical descriptions of communication protocols and demonstrate your understanding of their operation;

  • describe the characteristics of circuit-switched and packet-switched networks, and of connectionless and connection-oriented modes in packet-switched networks;

  • describe the role played by primitives in the OSI reference model;

  • explain how ‘vertical’ and ‘horizontal’
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17.4 The database server

The computer block on the right represents the database server, which is dedicated to managing a database and making the data available to other computers in the network. The database server receives data via the network. It stores, retrieves and manipulates data, for example by retrieving your previous points total and adding to it the number of points you have ‘earned’ on this visit. This data is also sent back via the network to the checkout computer to show you the total number of poi
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2.1 Introduction

There are many types of system – not just ICT systems. For example, we all have a nervous system and, as you are studying T175, you are in a higher education system. Our homes have plumbing systems and electrical systems.

Activity 1 (exploratory)

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Other approaches to information security management

Many of the approaches to planning an ISMS to be found in the literature follow a three-phase, rather than a four-task, approach. For instance, Moses (1994) stipulates seven steps in three phases:

  • initiation: the identification of information assets and their security requirements;

  • analysis: the identification of possible risks to the security requirements of information assets, of the vulnerabilities to those risks, and
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5.2.4 Risk treatment

The risk treatment task is again carried out at unit level, in light of polices set out in Stages 1 to 3. The risks treated are those chosen for control at Stage 6.

  • Stage 7: select control objectives and controls For each risk chosen for control at Stage 6, a suitable control (countermeasure) must be selected from those suggested in the Standard or from elsewhere. The risks are treated in order of priority, according to the priority levels as
    Author(s): The Open University

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4.2 Information in an e-business age

Sharing information in business is itself a risky business. The information that is exchanged between b2b partners, for instance, may include order information, customer details and strategic documents. Such information could be priceless to outsiders. As you saw in the previous section, huge costs can result from information getting into the wrong hands.

In sharing information, an organisation also needs to be aware of the various laws, regulatory frameworks and codes of practice. Fail
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3.3 Incentives

Activity 8

Reread the short section entitled ‘Benefits of an information security management system’ at the end of Chapter 1 of IT Governance: A Manager's Guide to Data Security & BS 7799/ISO 177799 (the Set Book). In light
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5.6 Reliability and usability

In this context we will define reliability as the ability of a technology to perform its intended function, without failure, under stated conditions and for a stated period of time. It is beyond the scope of this unit to provide a detailed comparison of the reliability of WiFi and Bluetooth – we simply want to alert you to some of the issues. Broadly these are:

  • What is the likelihood of data errors being introduced during transmission?


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4.5 WiFi network structure

A WiFi network can operate in one of two different modes: ad hoc mode or infrastructure mode

In an ad hoc network, stations communicate with each other directly, without the need for any intermediary or central control. This means that when one WiFi device comes within range of another, a direct communication channel can be set up between them. This is known as peer-to-peer communication. Additional devices can join the network, all communicating with each o
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3.6 Routers

One type of network device we haven't mentioned is a router. This is because a router generally works at the edge of a LAN rather than within it. A router can operate at a level that is independent of specific LAN protocols so it can be used to join an Ethernet LAN with a LAN that uses different protocols. A router holds information about the structure of a network and can make decisions about how data should be routed through it. As well as being used to connect together different typ
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3.5 Establishing Ethernet standards

The first Ethernet network was developed in the early 1970s, long before the days of the World Wide Web and personal computers (PCs). It was designed by researchers at the Xerox Palo Alto Research Centre in California, USA to connect the Centre's ‘Alto’ computers to an office printer.

Ethernet's journey from its modest roots to become the dominant network technology is a fascinating one. One of the main reasons for its success lies with the decision to publish the standard. Standard
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2.2 Memory

You should now be beginning to build up a picture of what a computer is: you know it needs input and output devices to communicate with the world outside and a processor to carry out the instructions that are programmed into it. But where are these instructions stored within the computer? The answer is that they are stored within what is called the computer's main memory, along with any data needed to carry them out.

However, the main memory in computers like PCs is much too smal
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4.2 Netiquette

Work through the following material on ‘netiquette’ and then try the quiz at the end of the section.


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2.1 Networked devices you use every day

The next activity aims to get you thinking a bit more about how ICT systems form part of your own life and to make you more aware of how you are living in a networked world. ICT systems are embedded in many everyday experiences and we have become so used to this that we hardly notice that we are using them.

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7.4.1 Architectural patterns

A software architecture is the broad structure of a software system. It describes its parts and how they are put together, and also captures an underlying rationale and associated concepts, such as professionalism (liability) and constraints (such as standards and economics). The term architecture is, again, reminiscent of its use in buildings.

Architectural patterns (also known as architectural styles) codify recurrent software architectures by describing the key
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