The Internet has now been around for several decades and has changed the way we do all kinds of things. To attempt to describe in detail the many services now available via the Internet and the World Wide Web would be a never-ending task, because the list gets longer every day. The following sections outline just some of the Internet services that are available.
Electronic mail (e-mail) is one of the oldest and probably still the most widely used forms of electronic communication. E-mail client software on the user's computer provides a graphical interface to the e-mail system that allows users to compose and send messages, or retrieve and read incoming mail. The client program can be configured to periodically check the user's mailbox on the mail server and download any mail held there to a mailbox on the user's computer. It can also provide information about the status of messages sent and received, such as whether an incoming message has been read, or whether an outgoing message has been delivered and read. Incoming messages can be forwarded to other recipients, and mailing lists allow an outgoing message to be sent to multiple recipients.
Evolution - a Linux GUI e-mail client
Modern email systems consist of two distinct sub-systems. The user agent is the email client program that resides on the user's computer. This client program allows the user to create and send messages, and to retrieve and read incoming mail. The message transfer agent is a program that resides on an email server and facilitates the storage and transfer of email messages. Most user agents provide a graphical user interface, making it easy for the user to interact with the email system. Some of the functions typically supported by email systems are described below.
- Composition - most email clients provide a message creation and editing facility, and will automatically add the required address and other header fields needed by the message.
- Message transfer - the process of moving a message from the sender to the recipient. A connection must be established between the sender's computer and the mail server used by the recipient, after which the message can be transmitted. Once the message has been transmitted, the connection is closed. Once the sender has instructed their email client program to send the message (usually by clicking on the Send button), these processes are carried out by the system automatically, without the need for further user intervention.
- Reporting - the sender will usually have access to information about the status of messages that have been sent, such as whether a message has been delivered successfully, or if a problem has occurred to prevent delivery.
- Rendering - incoming messages must be displayed in a format that can be read by the recipient. This may involve the use of appropriate software if the message is received in a non-standard format like HTML, or contains attachments such as images or sound files.
- Disposition - this refers to a number of operations that can be applied to messages that have been received. The user may wish, for example, to delete unwanted email either before or after reading it, save it to a specific directory, or retrieve and view previously saved messages.
Other services typically provided include the ability to forward received messages to one or more email addresses, to create mailboxes for storing incoming and outgoing messages, and to compile mailing lists that allow the user to send messages to a pre-defined group of recipients without having to specify all of the individual email addresses each time. Message transfer agents are protocols, like the Simple Mail Transfer Protocol (SMTP), that move messages from one computer to another. To send a message, a user must provide the message itself and (as a minimum) the destination e-mail address in the correct format, e.g. mailbox@domain, which message transfer agents will use to deliver the message to the correct mailbox. The email envelope encapsulates both the message itself (the message body) and all of the information needed by the transfer agents in order to ensure that it gets to the recipient (the message headers). The header information includes the recipient's email address, and the priority and security levels required. The transfer agents use the address information to route the message in the same way that the post office uses the address on a letter. When creating an email message, the user must provide the text of the message itself, the recipient's email address, and any other parameters required, such as a subject or a priority level. The email address must be in the correct format, i.e. mailbox@domain. The message body can be anything the user types in, and is often followed by a signature which can contain information about the sender, and the sender's organisation (including various kinds of disclaimer).The message headers contain control information for user agents, including the recipient's e-mail address. Some of the more commonly used header fields are described below.
|To:||E-mail address of primary recipient|
|Cc:||E-mail address of secondary recipient(s)|
|From:||Name of sender|
|Sender:||E-mail address of sender|
|Received:||Line added by each transfer agent en route|
|Date:||Date and time message was sent|
|Reply-to:||E-mail address to which replies should be sent|
|Message-Id:||Unique number for referencing message|
|In-Reply-To:||Message-Id of message to which this is a reply|
|Subject:||Short summary of message|
|References:||Other relevant Message-Ids|
In the early days of the Internet, email messages were just text messages based on the ASCII character set. This approach is no longer sufficient due to the number of international alphabets that must be supported, including non-Latin alphabets such as Hebrew and Russian, and languages that don't have an alphabet as such, like Chinese and Japanese. Messages may even consist largely of non-text content, such as graphic images, audio or video files. The Multipurpose Internet Mail Extensions were developed in order to add structure to the message body by defining encoding rules for non-ASCII messages. In this way, the message transfer agents could continue to function as they had previously, and only the user agents needed to be changed to handle the new, more complex message structure. MIME defines five new message headers, which are shown below.
|MIME-Version:||Identifies the MIME version|
|Content-Description:||Human-readable string describing the message contents|
|Content-Transfer-Encoding:||How the body is wrapped for transmission|
|Content-Type:||Nature of the message|
The Content-Type: header specifies the nature of the content within the message body. It is broken down into type and subtype, separated by a slash:
The subtype must be stated explicitly in the header, as there are no default values. Some of the more common types and subtypes are listed below. Many new MIME types have been added since the original specification was published, and new ones come into being all the time as new file formats are created.
|Richtext||Text including simple formatting|
|Image||Gif||Still picture in GIF format|
|Jpeg||Still picture in JPEG format|
|Video||Mpeg||Movie in MPEG format|
|Application||Octet-stream||An uninterpreted byte sequence|
|Postscript||A printable document in PostScript|
|Message||Rfc822||A MIME RFC 822 message|
|Partial||Message has been split for transmission|
|External-body||Message itself must be fetched over the net|
|Multipart||Mixed||Independent parts in the specified order|
|Alternative||Same message in different formats|
|Parallel||Parts must be viewed simultaneously|
|Digest||Each part is a complete RFC 822 message|
The application type is a catchall for formats that require external processing not covered by one of the other types. An octet-stream is just a sequence of uninterrupted bytes. On receiving such a stream, a user agent would probably prompt the user to copy it to a file for subsequent processing, which would be left to the user. The postscript subtype refers to the PostScript language from Adobe Systems that is used for describing printed pages. Displaying an incoming PostScript message is achieved by executing the PostScript program it contains.
The message type allows one message to be encapsulated inside another. The partial subtype makes it possible to break an encapsulated message up into pieces and send them separately (for example, if the original message is too long). The parts of the message can then be reassembled at the destination in the correct order. The external-body subtype can be used for very long messages. If the case of a video file, for example, instead of including the MPEG file in the message, an FTP address is provided, and the receiver's user agent can retrieve the file when it is needed.
The multipart type allows a message to contain more than one part, with the beginning and end of each part being clearly delimited. The mixed subtype allows each part to be different, with no additional structure imposed. With the alternative subtype, each part must contain the same message, but be expressed with a different medium or encoding (or in different languages). This hopefully enables the recipient to display the message in a format that is supported on their computer, even if this is not the format originally intended by the user (e.g. ASCII text as opposed to Rich Text format). The alternative subtype can also be used for multiple languages.
SMTP, POP3 and IMAP
In most cases, it is not practical to send email messages directly from one user's computer to another. Instead the message is sent to the recipient's mailbox, which resides on a mail server, using the Simple Mail Transfer Protocol (SMTP). In order to deliver an email message, the client must establish a TCP connection to port 25 on the server. An email daemon on the server waits for incoming email messages on port 25, and copies them into the appropriate mailbox. If a message cannot be delivered, an error report containing the first part of the undeliverable message is sent to the sender.
Once the TCP connection has been established, the client waits for the server to send a message providing its identity, and indicating whether or not it can receive mail. If not, the client releases the connection and tries again later. Otherwise the client sends a message identifying who the email is from, and who it is going to. If the recipient mailbox identified by the client exists on the server, the server asks the client to send the message. The client then sends the message, and the server replies with an acknowledgement. When all messages have been exchanged in both directions, the connection is released.
A second protocol, POP3 (Post Office Protocol 3) allows a user to log in to the server and retrieve messages from their mailbox, which are then stored on a local drive. The message is normally deleted from the user's mailbox on the server once it has been successfully downloaded.
IMAP (Interactive Mail Access Protocol) is another, more sophisticated protocol that stores both incoming and outgoing email on the server so that the user can access their email from any computer. The email messages remain on the server until explicitly deleted by the user, and are not downloaded to the user's computer.
E-mail is delivered over a TCP connection to port 25 of the destination mail server using SMTP. An e-mail daemon, whose job it is to monitor this port, transfers incoming messages from them into the appropriate mailbox. If a message cannot be delivered (usually because the named mailbox does not exist on the server) an error report is generated and sent to the incoming message's point of origin. The protocol used by a recipient to retrieve mail from their mailbox on the server is Post Office Protocol 3 (POP3), which allows the user to log in and retrieve messages. By default, messages that have been downloaded to a recipient's computer are deleted from the server. The Interactive Mail Access Protocol (IMAP) is a more sophisticated mail protocol that stores all incoming and outgoing mail on the server so that mail clients with mailboxes on the server can access their e-mail from anywhere. Mail is not downloaded to the user's PC, and is only deleted from the client's mailbox if the client specifies that it is to be deleted.
SMTP and POP3 are the protocols most commonly employed in an exchange of email messages
Computers connected to the same network can share files relatively easily. Transferring files across the Internet requires a different approach. Files can be downloaded from a Web server using HTTP, but if a large number of files need to be transferred, using the File Transfer Protocol (FTP) is more efficient. When you copy a file from a remote computer to your own computer, you are downloading the file. When you copy a file from your computer to the remote computer, you are uploading the file. Transferring files to or from a remote computer with FTP usually requires the user to log in to the remote computer using a valid username and password. Anonymous FTP allows the user to login and download files using a special guest account. This usually involves logging in with the user name anonymous, and entering an e-mail address as the password. Windows has a built-in command line FTP program, but most people find a graphical FTP client program easier to use.
A Windows command-line FTP session
The Core FTP LE client (illustrated below) can be downloaded freely from www.coreftp.com. Once the client has established a connection, files can be uploaded to, or downloaded from, the server. The window on the left displays the current working directory (CWD) on the local computer, while the window on the right shows the current working directory on the server. You can use the file navigation icons to change the current working directory on both the local computer and the remote server. To transfer a file (or directory), you simply highlight the file in the source window and click on the (left or right facing) arrow above the source window. You should shortly see a copy of the file (or directory) appear in the destination window.
The Core FTP LE client
Telnet is an Internet protocol developed in 1969, and was the subject of one of the first Internet standards. Telnet runs over a TCP connection, typically establishing a connection through port 23 on the remote host, and is typically used to provide access to a command-line interface on a remote computer, allowing the computer running the Telnet program to act as a terminal for the remote machine. For this reason, Telnet is often referred to as a terminal emulation program. Telnet clients are available for most operating systems, including most versions of Microsoft Windows, although Windows has its own command line Telnet program (see below).
Because it is not considered particularly secure (Telnet does not encrypt any data transmitted, including passwords, and has no authentication mechanism) the use of Telnet has declined as a means of remote access in recent years, in favour of the Secure Shell protocol (SSH). SSH provides (more or less) the same functionality as telnet, with the added security of strong encryption and public key authentication that allows the identity of the remote computer to be verified. Extensions to the Telnet protocol have added Transport Layer Security (TLS) and the Simple Authentication Security Layer (SASL), but most Telnet implementations do not support these extensions. Telnet clients still find use in diagnosing network problems, as it provides a convenient way to communicate with network devices without the need for specialised client software (as a simple way to send commands to a network server, for example).
A Windows-Linux telnet session over a private local network
Internet telephony, or Voice over Internet Protocol (VoIP) refers to transmission technologies that facilitate the delivery of voice communications over the Internet. VoIP systems interface with the conventional public switched telephone network (PSTN), and carry digital voice data as a stream of IP packets. If a user has a broadband Internet connection, they can use an Internet (VoIP) phone or a computer to connect to a VoIP service provider. Internet telephone calls can be made at the same time that the Internet connection is being used for other purposes, such as downloading files or browsing the World Wide Web.
Because the Internet is inherently unreliable in contrast to the circuit-switched public telephone network, Internet telephony is potentially more problematical than using conventional telephone services. Voice data is sampled eight thousand times per second, and each sample is digitised and becomes part of the payload of an IP packet. The digitised samples encapsulated within a single packet constitute a VoIP frame. The number of samples in each frame can vary, depending on the encoding scheme used, from one to as many as sixty-four.
Congestion on the Internet can cause packet loss, which will result in gaps in the voice data. Obviously, the more samples that are packaged into each frame, the bigger the gap will be if one or more packets are lost. Conversely, if fewer samples are packaged in each frame, there may be significant delays in voice transmission. Since the continuity of the voice data is the most critical factor, some packet loss must be tolerated, although excessive packet loss can result in momentary but noticeable loss of audio. A number of techniques have been developed to reduce the occurrence of packet loss, and advances in VoIP technology are improving both the reliability of, and the voice quality provided by, VoIP.
It is now possible to make free "telephone calls" from one computer to another almost anywhere in the world using VoIP software packages like Skype. Instead of a telephone number, users are identified by a unique name on the Skype network. Providing both the person making the call and the person being called have the Skype software package installed and online, they can conduct a conversation using standard headsets. It is also possible to make calls from a computer running Skype to a landline or mobile phone. Although there will be a metered charge for this service, the rates are in most cases only a fraction of standard national or international charges.
The Skype user interface
Some companies provide a service that allows users to make VoIP-calls using standard analogue telephones. Both the telephone number you wish to call and your own telephone number must be entered into the fields provided in the call setup screen, either on the company's Website, or using client software that the company has provided. Once you confirm that the call is to be made, the call is set up between your telephone and that of the person you are calling. If call setup is successful, your phone will ring. When you pick it up, you will hear the phone ringing at the other end. Local calls can usually be made free of charge, as can overseas calls to certain countries (income is usually generated by advertising). Other destinations might incur a metered charge, although calls are usually still much cheaper than conventional long distance telephone calls. One word of caution, however: you are submitting telephone numbers (yours and those of the people you contact) to a third party. It is advisable to carefully check the terms and conditions of service and read any privacy notices before divulging personal information of any kind.
The Voipcheap home page (www.voipcheap.com)
Bulletin board systems
A bulletin board system (BBS) is a computer system running software that allows users to connect to the system using a terminal program. When bulletin board systems first appeared in the late 1970s, long before the advent of the World Wide Web, they were accessed over a phone line using a modem. During the 1990s, access also became possible via Telnet or packet radio links. Once logged in, a user could download or upload software or data, exchange messages with other users, or read news items. Most bulletin board systems were run as a hobby by the system operator (or "sysop"), and BBS computers were typically located at the sysop's home. Others were subscription-based, or were operated by a business as a means of providing support to its customers. Many of the smaller bulletin board systems were restricted to local use, because the dial-in mode of access meant that connecting to a non-local bulletin board system involved the same cost as a long-distance telephone call. Access was often unreliable, and many of the smaller systems could only be accessed by one user at a time.
The Roughnecks BBS (accessed using the mTelnet client software)
The early systems were slow due to the low modem speeds (110 and 300 baud) of the late 1970s. Speed improved with the introduction of faster modems in the early 1980s, and as a result the popularity of bulletin board systems grew. Information was mainly text-based, although extended IBM characters could be used to create primitive graphics. Before internet access became widely available, networks of bulletin board systems provided email and messaging services, with some even providing a gateway to Internet email services. For the most part, connectivity between BBS networks was relatively slow, with each system having to dial up the next in line to pass on files and messages.
The largest BBS network was FidoNet, which is still active today, though much smaller than it was in the 1990s. Other, similar networks used the same technology, and became known as Fidonet Technology Networks (FTNs). The larger networks could accommodate a number of users simultaneously by employing multiple phone lines and a BBS computer running multi-tasking software, or multiple BBS computers connected by a local area network (LAN). As Internet access became more widely available from the mid-1990s, traditional bulletin board systems declined in popularity, and have largely been replaced by online forums. Some survive, and now have a Web-based user interface.
The Roughnecks BBS Web site (www.theroughnecks.net)
An Internet forum, or message board, is an online discussion site. It is the Web-based equivalent of the older bulletin board system (BBS), and as such is an application for managing user-generated content. Web-based forums first appeared circa 1996. Most, though not all, require users to be registered as members before they can post (upload to the server) any messages or start a new thread (a thread is a specific topic). Members will normally post messages to the forum using their username (usually an alias), and will only be allowed to do so after having logged in with a legitimate username and password. All postings relating to a particular thread will be visible to logged in members, and will be displayed one after the other in the reverse order in which they were received (or moderated), with the oldest (or original) posting usually appearing at the top of the display window. Each posting will identify the member that posted it by displaying their alias, and will also publish the date and time that the posting was issued. Threads and their postings are maintained in a hierarchical directory structure by the forum's software.
Forums are either monitored or moderated by administrators who are responsible for maintaining the forum and enforcing its policies and conditions of use. There is usually a code of acceptable conduct that members are expected to abide by, and a frequently asked questions (FAQ) page that contains answers to some of the questions commonly asked by new members. Although it is the job of the administrators to enforce the code of conduct, there is usually a mechanism to allow ordinary members to report postings that could be considered to be offensive, or other forms of misconduct. When the rules are broken, a warning may be issued. If an offence is serious, the member committing the offence may be suspended from posting in the forum for a period of time, or may be banned from using the forum altogether.
Any content judged to be offensive will be deleted immediately by an administrator. If a particular thread appears to be attracting offensive postings for some reason, it can be locked so that no further messages can be posted to it. If the topic itself is considered to violate the code of conduct, the thread and all of the postings related to it may be deleted. In some forums, a word censor is incorporated into the forum's software that looks for words that are considered to violate the rules, such as racially offensive terms or swearwords. Such words are typically replaced by a string of asterisks (e.g. ********). In moderated forums, no postings appear until they have been first read by an administrator to ensure that the content is acceptable.
Most forums have a particular focus of interest (e.g. scuba diving, stamp collecting or fishing), although a forum may have a number of active threads at any one time, each of which may revolve around a particular aspect of the forum's general subject area. Most forums are Web applications, and the only software needed to participate is a standard Web browser such as Internet Explorer or Firefox. A member can start a new thread by posting a message about some topic that they feel will be of interest to other members, or can post replies to comments made in an existing thread. Guests are usually permitted to view the contents of a thread, but may not post comments of their own or start a new thread. Members are normally allowed to delete or modify their own postings, but may not edit other members' postings (unless they are also administrators). There is nearly always a limit on the length of a posting in terms of the number of characters permitted, but this is usually a very large number (in the tens of thousands). Threads and their associated postings usually remain open for viewing or posting further comments for some time, unless they are removed by an administrator for some reason.
The Fishing Forum (www.fishing-forum.info)
Travel information is available online for just about any kind of journey, whether it is a trip to your local town centre or a holiday or business trip abroad. You can book cheap rail tickets, compare prices for flights to Florida, plan a World cruise, or simply check out your local bus timetable.
The Raileasy home page
The Raileasy Web site allows you to enter details of your journey using a simple form, and presents alternative rail service options and prices. Once you have decided which journey options are best for you, you can book your tickets and pay for them online using a credit or debit card. The tickets will be sent to your home or business address.
The Cheapflights home page
There are numerous Web sites operated by airlines and ticket agencies that allow you to find cheap airfares, book and pay for flights, and even arrange for accommodation or car hire at your destination.
The Plymouth CityBus home page
Most local and national bus companies publish information about their services online, including of concessionary rates and the pricing and availability of season tickets.
The term "chat" is generally used to refer to online conversations in which participants send text messages to each other in real time using special chat client software. The networks that facilitate this form of communication are sometimes referred to as social networks, because many people use them to interact with others socially. Participants in chat often have an online name, referred to as a "nick" (as in nickname) or "handle". The technologies most frequently employed for this type of communication are instant messaging and Internet Relay Chat (IRC).
Instant messaging is widely used, and usually involves a conversation between just two people, although most instant messaging software can accommodate group chats, where three or more people can take part in the same conversation. The instant messaging software itself is usually available free of charge. Microsoft's current instant messaging client software is called Windows Live Messenger.
The Windows Live Messenger client
To use Internet Relay Chat (IRC) you need an IRC client program. There are a number of these available, both proprietary and open source. To chat with someone, you must be on the same network. Each network has a large number of chat rooms (called channels). Each room is dedicated to a particular topic or theme. Unlike networks like Microsoft's MSN, there is no central user registration. While it is therefore perfectly possible for two people to be using the same nickname, this only causes problems if they both happen to be trying to use the same network at the same time.
The XChat client running under Linux
Chat rooms usually have rules that visitors must follow. For example, the rules might require visitors to refrain from using offensive language or expressing racist views. Advertising is not usually allowed, and some chat rooms are moderated by regular members who have the authority to issue a warning to visitors who break the rules, or even evict them from the room. The code of acceptable behaviour will vary from one chat room to another. There are even chat rooms that encourage visitors to abuse one another, although most rooms have a more orthodox set of rules that prohibit anti-social dialogue. There are also a number of conventions that should normally be observed - for example, typing whole words in upper case characters is usually considered to be "shouting" and is frowned upon.
When engaging in chat, the client software usually displays a list of the other people who are in the same chat room, and will display a message each time someone enters or leaves the chat room. It is often possible to see a "profile" of each participant by clicking on, or highlighting their name. Apart from a person's chat name, the amount of information included in a profile is, for the most part, at the discretion of the individual user. Even if a detailed profile is available, including a photograph, it is often difficult to ascertain whether the information posted is genuine. Not everyone who participates in a chat room is what they seem, so it is wise to be cautious in terms of how much information you reveal online.
The comments being transmitted by those taking part in a chat are displayed in a large text window that represents the "room", and that is visible to all users. Comments are usually displayed in this communal area in the order in which they are sent. Each user types their message into a much smaller text box and hits the return key (or uses a "Send" button) to send their message, which should then become visible in the main window immediately. Sometimes, a user will enter a chat room and read the messages there without sending any of their own, a practice known as "lurking". It is considered good manners to at least make some kind of introductory remark when entering a chat.
In recent years, the concept of chat has been extended to graphical environments that allow users to assume a three-dimensional on-screen identity called an avatar. The avatar can have whatever physical characteristics the user chooses, and can move around freely in a virtual world. One of the best known of these virtual worlds is Second Life developed by Linden Lab and launched in 2003. A free client program (or viewer) is available that allows users to interact with each other. Users are called "residents", and can socialise with other residents, participate in individual or group activities, travel around the virtual world (or "grid"), and even run or take part in a virtual business (Second Life even has its own currency!). Despite some controversy over the exact nature of Second Life (i.e. as a game, a social network or a virtual world), most users use it primarily as an entertainment medium in which they can interact with others.
The Second Life "What is Second Life" page
Imagine a user who wants to write a report on the trends in cult TV programmes, and is looking for information to help with this task. The user goes to Google, types in some keywords, gets several thousand results, and opens some of the more relevant-looking pages. If the material is found to be useful, the user might copy and paste the contents into a word processing document, and carry on browsing. After several hours, the user has a collection of bookmarks, printed pages, and saved documents that will later be read in more detail.
The ability to find information quickly is a critical skill in today's competitive world. The way that researchers gather information depends on the kind of information being sought. If a specific goal has been defined, information gathering will be systematic and focused on specific information targets. Potential sources can be scanned quickly to determine how likely they are to provide useful information, and if so bookmarked or saved to disk for a more detailed inspection at a later time. Less specific goals may result in relatively undirected searches with no real focus. The way in which the researcher carries out their search will also depend on their Web searching skills and their existing knowledge of the subject of their research. If no definitive starting point has been identified, a search engine will often be used to find potential sources of information. Researchers can use any number of search engines, although we all tend to have a favourite. Currently, Google is the most widely used search engine.
Google is currently the most widely used search engine
Organisations and individuals use the Web as a source of information for many different reasons. The value of the information found is judged according to where it comes from, how up-to-date it is, and how relevant it is to the task in hand. Sites which have provided useful or accurate information in the past will tend to be trusted more readily than new or untried sites, as will sites that have been recommended by others working in the same field of research. Over a period of time, the seasoned researcher will build up a collection of bookmarks pointing to useful or potentially useful Web sites. This collection of bookmarks will tend to grow rapidly as new sources of information are discovered, and will need to be organised according to the category of information each bookmark refers to.
Often, a broadly based search will be initiated in order to accumulate background information about a topic before narrowing the focus of the search to determine specific details. Learning to narrow the search through the use of appropriate keywords and phrases is a skill that is developed through experience. In some cases, the researcher may wish to follow up their Web-based activities by contacting the individual or organisation that owns a particular Web site in order to try and obtain additional information not found on the site itself, or to request permission to re-use the content in its original form (if there are copyright issues, for example).
Being able to find information instantly about any topic is, on the face of it, of huge benefit to those involved in any kind of research. Since anyone with a degree of computer literacy and an Internet connection can now publish information on the Web, however, the problem has become one of determining how reliable the available information is. Far too many Web pages contain content that is, for the most part, the author's unsupported opinion about their chosen topic. Often, the information is inaccurate and badly written. For each research task undertaken, therefore, a set of criteria is needed that will allow sources to be evaluated in terms of the usefulness of the information they provide. Professional researchers often check a Web site for accuracy against other sources of information such as reference works and original documents.
One of the most important criteria is to establish the credentials of the individual or organisation publishing the material, which will obviously have some bearing on whether or not the accuracy and quality of the information can be relied upon. Another concern will be the date on which the material was published, or how recently it has been updated, which can sometimes be difficult to determine. While many sites include the date on which a page was published or updated, many more do not. Even if the information presented is current, accurate, and from a reliable source, its value will depend on how appropriate it is for the target audience. This will depend on the breadth of the information (i.e. what aspects of the topic are covered) and its depth (i.e. what level of detail is provided).
News & Weather
Many television news services now have a Web sites. Examples include the BBC (see below) and CNN, and there are many others. The content includes up-to-the-minute news stories, features and video footage of news and events from around the world.
The BBC News Front Page
Most popular national and local newspapers now have a Web presence, which is essentially an online version of the content published in their daily print editions, including the day's news items. One benefit of the online services provided by the media in general is that they often provide search facilities that allow users to search for and retrieve archived news reports and features.
The News page of the Mail Online
There are a number of Web sites that provide online information about the weather, including short-term and long-term forecasts. The Meteorological Office has its own weather pages, and also provides information about a number of related issues, such as climate change and the science behind the weather forecasting process, as well as a number of educational resources for schools and colleges.
The Meteorological Office Weather page
Online gaming has become increasingly popular in recent years, reflecting both the growing numbers of Internet users and the increasing availability of high-speed broadband connections. Many kinds of online games are available, from simple single-player platform games to highly complex, multiplayer games in which players interact in a virtual world. Many of the multiplayer games have given rise to associated online communities, where players can exchange views and tips, and interact socially.
The first person shooter (FPS) game that probably did more than any other to popularise multiplayer online gaming was Doom, a landmark 1993 computer game by id Software that pioneered immersive 3D graphics and networked multiplayer gaming on the PC platform. Doom was distributed as shareware and downloaded by an estimated ten million people in two years. Other FPS games from the same period are often referred to as "Doom clones". Doom introduced the concept of the "deathmatch", where multiple players played against each other online. Many of today's online games, like World of Warcraft, require players to pay a monthly subscription, although some allow players to play for free, relying on advertising revenue rather than subscriptions.
The "World of Warcraft" home page
Internet radio is an audio broadcasting service transmitted over the Internet. This type of broadcasting is sometimes called Webcasting, and presents the audience with a continuous stream of audio. Many Internet radio stations are associated with conventional radio stations, although a number of Internet-only radio stations operate independently. Internet radio is particularly popular with expatriates, and offers the same kind of content (news, sport, music etc.) that is available on conventional radio stations. The streaming technology most often used to broadcast audio online uses a "lossy" audio codec designed to compress the data stream sufficiently to ensure that audio content can be delivered in real time. Buffering is usually implemented by the client software to ensure a continuous output stream.
The home page of BBC Radio 1
Anyone with a broadband connection and the appropriate media player software can watch streamed pre-recorded or live Internet television free of charge, or for a small annual subscription. Users have the choice of many thousands of channels from all over the world although the quality of service experienced very much depends on the speed of the user's internet connection.
JLC's Internet TV (Classic FM)
JLC's Internet TV is a freeware program that allows you to watch thousands of Internet TV channels that are freely available online. Channels can be rated by users, so it is easy to see which channels are the most popular. You can select a country of origin for channel listings, and you can also filter the list of channels by category (for example, you can choose not to include religious or shopping channels).
Internet banking allows customers to conduct financial transactions on a secure Web site operated by their bank or building society. Customers can view their current balance, print a statement, pay bills, transfer money from one account to another and apply for a loan without having to leave their office or home. In order to access an online account and carry out transactions, the user must log in to their account using a valid username and password, and additional authentication details may be required before access is granted.
One of the most common forms of Internet fraud involves tricking the user into divulging their online banking username and password by sending them an email that appears to come from their bank or building society. The user is asked to log into their account in order to re-activate it (the account, it is claimed, has been de-activated because of "suspicious activity"). The user is asked to click on the link provided to take them to the bank or building society login page, but of course the login page (which often looks very authentic) is actually on the perpetrator's Web site.
A Lloyds TSB customer account overview
Bloomberg.com is the Internet presence of Bloomberg L.P., and is one of the most popular financial sites on the Web. Bloomberg is one of the world's biggest providers of financial software, business news, and financial information services.
The Bloomberg home page
Local information services
Most towns and cities in the UK now have one or more Web sites devoted to local news, activities and events. The "this is plymouth" Web site (below) is essentially the online version of "The Herald", Plymouth's local newspaper, and features include coverage of local news, sport, leisure, and entertainment.
The "this is Plymouth" home page
The Devon Link Web site (below) provides information to tourists and other visitors about Devon, including accommodation, transport, and places of interest.
The Devon Link home page
Jobcentre Plus is the government-funded employment agency and social security office for working-age people in Great Britain, formed when the Employment Service merged with the Benefits Agency in 2002. It is an executive agency of the Department for Work and Pensions (DWP) and reports directly to the Minister of State for Employment and Welfare Reform. Its Web site is aimed at assisting people to find work or claim benefits, and to help employers to fill job vacancies.
The Jobcentre Plus home page
The Reed Employment Web site is run by Reed Recruitment Agency, one of the largest employment agencies in the UK. The site allows jobseekers to search for vacancies by job title, sector, geographical area and salary range. The services offered to registered candidates include email notifications of vacancies, CV-writing tools, analyses of market trends across industry sectors, and job search facilities that can be tailored to match individual requirements.
The Reed Employment home page
The Automobile Association (AA) Web site provides information about the services offered by the AA, as well as information about motoring, travel and leisure activities.
The AA home page
The Royal Automobile Club (RAC) Web site provides information and advice about motoring as well as a route planner and information for RAC members.
The RAC home page
Central and local government
Directgov is "the official government Web site for citizens". It provides information about a broad range of subjects, including education, employment, taxation, health, transport and citizenship.
The Directgov home page
Most local authorities now have their own Web site that provides information about local government services and the local community. On the Plymouth City Council Web site, for example, you can find contact details for your local councillor, review local planning applications, check the dates of refuse collections, or read about the measures the council is taking to combat anti-social behaviour.
The Plymouth City Council home page
The NHS Direct Web site is an online health advice and information service provided by the National Health Service that first appeared in England in 1998. A similar service (NHS24) was introduced in Scotland by the Scottish Executive Health Department in 2004. The site provides a contact telephone number for those wishing to speak to a health advisor, a self-help guide, a comprehensive health encyclopaedia, and an online enquiry service that allows visitors to the site to request information via email.
The NHS Direct home page
The leading provider of healthcare in the UK, BUPA, also has an online presence. Their Web site provides details of the services they can provide, including medical insurance and a free online health check.
The Bupa home page
Education and training
Distance learning, by definition, involves a degree of physical separation between student and teacher, and requires some form of communication channel to be available between the provider and the recipient of learning. Distance learning is by no means a new concept. Isaac Pitman taught shorthand in Great Britain via correspondence in the 1840s, and the development of the postal service during that century led to the appearance of a number of commercial correspondence colleges. The University of London was the first university to offer distance learning degrees, establishing its External Programme in 1858. The Open University (OU), one of the best known institutions providing distance learning, was established in 1969, long before the Internet became a popular communication medium. The OU initially used both radio and television to deliver its learning material, much of which is now available via the Web.
You can read a History of the OU on their Web site(http://www.open.ac.uk)
The pace of technological change and the speed with which economic and social paradigms shift in the modern world have made the need to frequently learn new skills or update existing ones a fact of life for many. The demands of widening participation in lifelong learning will not be met solely from traditional sources of education and training due to insufficient physical infrastructure and a shortage of suitably trained teachers, and must therefore be met by other means. Internet technologies can be used both to augment conventional teaching methods and to develop new approaches, as well as having the potential to accommodate a broad range of learning styles and reach a more diverse audience. Today, there are a number of organisations, both private and public, offering a diverse range of online courses. One such organisation, Learndirect, is the public face of the University for Industry (Ufi), which was set up in 1998 to help implement the government's policy on increasing the take-up of learning by small-to-medium enterprises (SMEs) to raise UK skill levels, and thereby improve productivity and business performance.
Learndirect's home page
Online distance learning is perhaps the most cost-effective and efficient way of satisfying the additional demand, and will make post-compulsory education and training both more accessible and more affordable to those who can benefit from it. From the mid 1990s onwards, the falling cost of personal computers, coupled with the widespread availability of Internet access at a reasonable price, has led to a phenomenal growth in the number of organisations and individuals who have access to the Internet and, as a consequence, to new and exciting virtual learning environments (VLEs). Today, a majority of households in the UK have access to affordable broadband Internet services.
Because distance learning is essentially a student-centred process, questions have arisen about the lack of social interaction that is part of a more traditional learning environment. There will still be a degree of social interaction, however, albeit via an electronic medium. Students and tutors can communicate via e-mail, instant messaging, or even video conferencing. Students can also interact with each other using chat facilities or forums, and may even participate in online collaborative activities.
The speed of change in the modern world means that learning materials will need to be frequently updated. Electronic media can be revised and uploaded to an Internet Web server with minimal delay, unlike printed, magnetic or optical media which would require a significant amount of time to produce and distribute. If learning materials are produced in a modular form, the individual modules can be stored in a central repository and used for any number of different courses, which can be tailored to the needs of specific groups or individuals by selecting and grouping the appropriate modules. Most of the learning materials used as handouts or worksheets in a more traditional classroom environment are already produced in electronic format using word processing or desktop publishing software, so converting it into a format suitable for online delivery as part of a VLE is not too difficult. The creation of truly interactive multimedia content may require more time and expertise.
New College, Swindon use the Moodle open source VLE
Formative assessment is relatively easy to implement, can provide immediate feedback to students, and allows tutors to assess learner progress. Such assessment may include multiple choice tests, essay questions, and interactive multimedia problem-solving exercises. Student results can be recorded in a database and made accessible to course tutors. One of the more difficult questions related to online learning is that of how to provide accreditation of learning. Formal assessment poses more problems because of the need to verify the identity of the student, and to ensure that cheating does not occur. Reliable methods of online accreditation are being developed, although an interim solution has been to bring distance learners into an authorised centre to undertake formal assessment under appropriate supervision.
Online learning is still in its infancy and there are a number of questions that need to be resolved, such as how best to provide learner support in an online environment, and how to implement formal assessment reliably. It may be a while before it is possible to achieve a nationally recognised qualification without having to attend a registered examination centre, and for some types of course it may simply not be possible. Online learning will not suit all learners, since the nature of self-directed learning necessitates a degree of intrinsic motivation, self discipline, and a reasonable degree of computer literacy. There are, however, virtually unlimited opportunities for the use of Internet and communication technology (ICT) to enhance the learning experience, and to accommodate a wide range of learning styles.