Learning, Teaching and Researching on the Internet

A Practical Guide for Social Scientists

Stuart Stein, S. D. Stein

• Publisher: Routledge
• Year: 2014
• eBook ISBN: 9781317882435
• Topic: Politics & International Relations
• Subtopic: Social Science Research & Methodology
• Index: Politics & International Relations

Learning, Teaching and Researching on the Internet: A Practical Guide for Social Scientists is directed at students and academic staff who want to be able to access Internet resources quickly and efficiently without needing to become IT experts. The emphasis throughout is on the harnessing of the large volume of potentially useful Internet resources to everyday requirements, whether these be focused on learning, teaching or research.

The Internet is a significantly rich information, communication and research resource for all those involved in higher education, whether they be students, academic staff involved in teaching and research, or educational administrators. Whilst the author has drawn on the large volume of technical literature, it is written on the basis of practical experience acquired over the many years of using Internet resources in the context of teaching undergraduate and postgraduate courses in the social sciences. In addition to extensive coverage on using Web browsers, searching for information at Web sites, in mailing lists and newsgroups, Part IV provides detailed annotations in the resources available at the best sites on the Internet collating materials on politics, sociology, economics, philosophy, psychology, history, human rights, European Union and other categories. The work is structured so that it will be found useful by both beginners and intermediate level users.

PART I

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Internet preliminaries

Chapter 1	A very brief introduction to the Internet
Chapter 2	Web browsers
Chapter 3	Internet addresses
Chapter 4	Referencing Internet materials

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CHAPTER 1

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A very brief introduction to the Internet

1.1 Local Area Networks

1.2 Wide Area Networks and the Internet

1.3 The World Wide Web

Most people who drive a car, use the telephone or watch television manage to do so despite the fact that they understand little about the workings of a car engine, digital exchanges or television transmission. It is equally feasible to locate and download information from Internet sources without comprehending its structure or how data is carried over it. This chapter offers a brief overview for those who are interested in understanding the way in which the Internet is structured and how information is transmitted over it. Those readers who have neither the time nor the inclination to delve below the bonnet can quite easily skip this chapter without impacting on their ability to locate, download, and manipulate information accessible over the Internet. Some of the terms explained here crop up in other chapters. The Glossary provides brief definitions of them and the Index makes reference to the pages where more detailed information is available.

1.1 Local Area Networks

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The Internet is not one network, but a network of networks. It constitutes a network by virtue of the fact that a large number of separate networks can be linked to each other and data can be exchanged between computers attached to them. The communication and exchange of data between machines attached to the separate networks can take place because the computers on them employ identical software and each network is attached to devices that route data between them. The software comprises a collection of protocols called the TCP/IP Protocol Suite, A protocol is essentially an agreed standard that is implemented in software programs so that the connecting computers can exchange data with each other, order it, and check that the data dispatched corresponds with the data received. An electronic mail message, for example, is sent from one computer to another, sometimes through holding computers en route. All the computers in the chain must include software that manipulates and orders the data identically so that the recipient can read the message in a format and order that corresponds to the data that was transmitted by the sender. The same applies to software applications that are moved over the Internet, to newsgroup messages and to Web documents. This is achieved through agreed protocols.

Before looking at the way in which data is exchanged between different networks it is necessary to explore briefly the operation of those smaller networks that link up jointly to form the Internet. The smallest form of self-contained network is referred to as a LAN, an acronym for Local Area Network. The network illustrated in Figure 1.1 represents some of the components on a LAN that you are likely to encounter in a small enterprise. This network comprises the workstations of employees, the network infrastructure between them, which is likely to be some form of cabling, a common server on which various programs and files are stored which can be accessed from the workstations, two printers and a modem.

Figure 1.1 Local Area Network.

In a large organization the computer network might consist of a number of interconnected LANs. So, for example, a sizeable university might have separate LANs for each of its major faculties and servicing departments. Communication devices link LANs. One such device is a bridge, whose function it is to copy data from one LAN to another. Another device that effects a similar outcome is a router. This is illustrated in Figure 1.2.

Figure 1.2 LAN interconnectivity.

In order for the separate components of a LAN to work seamlessly together exchanging data, it is necessary that all the devices attached to the network can communicate with each other. This is achieved through the use of network operating software. This ‘controls the data traffic flow in the network, converts transmission and reception speeds, translates different data codes produced by different computers, detects and corrects errors, forms data messages and performs user access functions. In its simplest terms the network software may be seen to behave like a form of operating system which makes resources dispersed across the network appear to be local to each user’s workstation.’ (Anderson, 1996, Foundations of Computer Technology p. 327). In other words, the network operating software ensures that the data that is being exchanged across the network arrives at the appropriate destination in the format that it is supposed to be in, that all of the data is transmitted and that it is in exactly the same order as it was before being sent. Network operating software also allows those connected to the LAN to share and exchange data files, to access common programs and peripherals such as printers, CD-ROM drives and modems, and to receive and send electronic mail.

The network infrastructure (cabling, microwave, radio signals), hardware (workstations, printers, modems, file servers) and software applications (word processors, spreadsheets, databases, etc.) are all means to an end, the production and distribution of information by and between those connected to the network. A key factor, therefore, is the means by which information is moved over a network. Data can be transmitted over Local Area Networks through a number of different mechanisms, namely through circuit switching, message switching and packet switching. Here I will be concerned only with the latter, as packet switching is the means by which information is also moved over the Internet.

With packet switching the data that is to be transmitted from one part of a network to another, say the contents of a word-processed file, a Web page or a spreadsheet, is divided up into small packets of data. The packet includes some of the data that is to be transmitted and header information. The header information consists of control and address codes that specify where the packet is to be delivered and provide for the control of errors, for instance loss of data in the course of transmission from one part of the network to another. If the file is being sent over a network on which there are a number of file servers the header specifies to which one the packets of data are to be sent. A schematic representation is illustrated by Figure 1.3.

CHECK BITS

DATA BITS

CONTROL BITS

Figure 1.3 Packet file components

As on a typical medium-sized to large LAN a significant volume of data will be regularly transmitted across its segments, it is necessary to ensure that all users can uninterruptedly access and transmit data. To avoid the creation of bottlenecks arising from the transmission of large bodies of data, most network operating software implements a sharing arrangement. This is achieved by limiting the volume of data that can be transmitted in each packet and ensuring that, when data is being transmitted from a number of sources on the network simultaneously, the data packets from one source alternate with those transmitted from others. In other words, a turn-taking procedure is implemented. This arrangement is known as packet switching, and a network that implements it is referred to as a packet switching network. The Internet is a packet switching network.

To summarize, a Local Area Network links together workstations and peripherals (file servers, printers, modems, etc.) for the purpose of accessing and transmitting data. Some form of cabling links the component parts. Network operating software monitors and controls the transmission of data across the network. Most LANs are packet switching networks. The data in a packet switching network is moved across the network in packets. These packets include portions of the data to be transmitted as well as control and addressing codes that ensure that the packet arrives at the correct destination, that the data is free from errors and that it is in the same format and order as intended by the sender. Finally, LANs can be connected to each other.

1.2 Wide Area Networks and the Internet

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From the above description of the workings of a LAN it might appear that creating a worldwide network is relatively simple. As LANs can be linked to each other, why not link all the LANs that exist in separate organizations to create a large network across which information can be transmitted and accessed? There are a number of reasons why this cannot be done. First, there are constraints on the size of a Local Area Network in terms of its cabling length. That is one of the reasons why a large organization is likely to have a number of LANs that are linked through communication devices as described earlier. The physical limitations on a LAN vary with the LAN technology that is used. However, 500 metres or less is not atypical. This, of course, militates against connecting LANs that are separated by distances greater than this. There are other reasons why an organization might set up a number of LANs irrespective of whether cabling constraints are operative, including the need to implement different levels of security on them and the use of alternative LAN te...

Table of contents

• Cover
• Half Title
• Title Page
• Copyright Page
• Table of Contents
• Preface
• Part I Internet preliminaries
• Part II Searching the Internet
• Part III Exchanging views on the Internet
• Part IV Social Science subject resources
• Part V Closure
• Glossary
• Bibliography
• Index