Filed under: IST 205 | Tags: IST 205 Learning Log Six - Spiral or Waterfall for Deve
When an organisation starts designing and building a web based application or system (with a system being any set of components that work together to achieve a goal) eventually there needs to be a feedback mechanism to ensure that the goal is achieved. To help achieve this ISD (Instructional Systems Design) is an approach that provides a step-by-step system to help design the application and evaluate the effectiveness of the application. This evaluation process is vital to ensure that the project meets its goals and that the project fulfills the customers needs. Many models exist to help this evaluation process such as the Waterfall and Spiral models. Below is a summary of these models:
Waterfall – Waterfall Model Image
The waterfall model shows a linear approach as the steps flow inevitably towards a final goal and each step must be completed before the next step can begin. This model however does not handle changes to the product design well as just like a real waterfall water can not flow back up the model. This model also has limited feedback between stages and provides no opportunity to include end users. This model is preferred by some however because it is stated that if time is spent early on making sure that the requirements and design of the project are perfect this will save you time, money and effort later on in the project. This model is also preferred by some because of its simple, structured design and approach. This model is best suited for small scale projects but doesn’t work well for large scale projects.
Spiral – Spiral Model Image
The spiral model (Boehm, 1988.) is a more complex model than the Waterfall model and therefore works well with large and complex projects, it does not work with simple projects however. This model states four major activities that occur repeatedly throughout the development process; planning, risk assessment engineering and evaluation. This means that the whole project is constantly being evaluated and changes being made to make sure the final goal is met. This model therefore can cope with the changes a project may face because it is constantly evaluating the project. This model for example would work well for a website project because a website is constantly changing and this model could cope with that and evolve to fit the project. With the evaluation this model also involves the end user before the project is completed as the end user can provide some input on changes that may need to be made when the prototype is in testing.
There are more than 100 different ISD models but almost all of them are based on the ADDIE model. This model stands for:
- Analysis
- Design
- Development
- Implementation
- Evaluation
The principles of this model is to bring structure to a design and that each step has an outcome that begins the next step. Using this generic model the designer:
- Develops an understanding of the users needs
- Designs the project to fulfill these needs
- Creates a prototype of the project
- Delivers the prototype to the user
- Evaluates the effectiveness of the project
Overall these ADDIE model types have been criticised by some for being too linear, too inflexible, too constraining and too time consuming and therefore advances on these models have been developed.
In these systemic approaches the whole development team work together from the start to rapidly develop prototypes that can be tested and amended upon feedback. Even these models have criticism however as projects are often developed under a fixed budget and schedule. Using this approach though it may take many versions and a lot of time before the project is completed, could the project afford this? This is the main drawback on the systemic approach.
A further model has been developed taking the best bits from the ADDIE and systemic approaches called the modified ADDIE model. This model sees rapid assembly of prototypes and evaluation of these prototypes to locate any flaws. Once these have been found and the user and developer agree on a final prototype the final version of the project is pulled together from all the good bits from the prototypes and a final evaluation is carried out. This model is well suited to small scale projects but may not work as well in a large scale project when the prototypes cannot be put together as quickly.
Overall these models can be used effectively to steer a project towards a final goal and a satisfied end user but it requires time to carry out evaluation and time to correct the errors found through the evaluation. It is impossible to say which is the best model because each model I have discussed suits a certain circumstance and therefore the best model depends on what project you are doing and the scale of the project. When deciding upon an ISD project the circumstances of the project must be taken into consideration before a well thought out design and evaluation cycle can occur. It also depends how much time and funding the project has because to produce prototype takes time and money and this may be something a project cannot afford.
Sources
Lecture Notes – The slide shows contained in this link provided some useful information on ADDIE models.
Outline Of Methodologies – Contains a useful sentence about focusing on customers needs.
Waterfall Model Image – Waterfall Model Image provided by Wikipedia.
Spiral Model Image – Spiral Model Image provided by Wikipedia.
Rejected Sources
Waterfall Model Information – I rejected this source simply because it contained the same information that I had already read up upon.
Waterfall Wikipedia – I rejected this source again due to the fact Wikipedia is not 100% reliable, i navigated to this page however to obtain a waterfall model image which I knew was trustworthy.
Spiral Wikipedia – I rejected this source again due to the fact Wikipedia is not 100% reliable, i navigated to this page however to obtain a spiral model image which i knew was trustworthy.
Filed under: IST 205 | Tags: IST 205 Learning Lof Five - Investigate RSS application
RSS (Rich Site Summary) is a format for delivery regularly changing web content to an individual. Its main use is as RSS Feeds as most news related sites and weblogs make the information on there pages available as RSS Feeds.
The main benefit of RSS feeds is that it easily allows users to stay informed and up to date on the information they have asked for because RSS Feeds send the information on the websites that the user has stated straight to them. This saves the user time as they do not have to go to each site individually, it keep them save as they do not have to give out their personal details to every sites newsletter and it provides all the information they want in one place so they can keep it organised the way that they prefer.
For RSS Feeds to work you need an RSS reader installed on you PC. There are many available on the Internet for all the major operating systems and the following links RSS Readers and RSS Reader Software show most of the best RSS readers available open source on the Internet. All of the listed RSS Readers do the same thing just in a different layout. What an RSS readers does is it goes to the sites you have pre-determined and gets all the latest links that you haven’t read, it then sends them back to the RSS Reader program and displays them for you. Therefore you can read and view all the latest news and links from your favourite websites with no need to visit the page yourself.
RSS applications are an example of an XML application because when the RSS reader is sending information from a website to the RSS reader it is using XML code. As seen in Learning Log Four XML is a very versatile plain text language and it is no different here. It is sending well formed XML code with the root node and child nodes together with the information that is requested wrapped inside the node tags. The information itself is inside tags such as Title and then the Body of text which then displays just the plain text of the website in your RSS reader. It uses the same XML declarations as stated in Learning Log Four and RSS using XML is just another case of a XML application.
RSS is not just restricted to gathering information off websites it has other uses also. For example Library Elf is an example of a RSS application. It uses e-mail and RSS to keep track of when your library books are due in and when reservations are ready to collect. This is useful for people who use library’s a lot because it can reduce the amount of fines and alert the user when books are ready for collection.
As you can see RSS is becoming ever more used in today’s society and as it grows there will be more uses for this technology put on the market.
Sources
Lecture Notes – Used as starting block of RSS uses
Other RSS applications – Used to gather information on Library Elf
Library Elf – Information on Library Elf
RSS Readers – List of RSS Readers available on the Internet
RSS Readers – More RSS Readers available on the Internet
Basic RSS Explanation – Basic information on RSS
The Extensible Markup Language (XML) is a document processing standard that allows the user to create and format documents. It is classed as Extensible because it allows the user to create and define their own elements. XML by itself does not do anything. XMl in its basic essence is plain text wrapped in tags that the user defines. When a XML message is sent the receiver must have some XML software installed that can read and display the message.
XML is used as a complement to HTML because in most web applications XML is used to transport the data and HTML is used to format and display the data on screen.
XML can be written well formed and not well formed, as good practice it is useful to make sure that when you write a XML document that it is well formed. This means that when you define a tag it must be closed at some stage. Also a well formed XML document can be represented by a tree. This means that the document has a root node tag and therefore has a closing root node tag at the end of the document. All other tags come between these two tags in the document structure.
The following example is taken from W3C:
1. <?xml version="1.0" encoding="ISO-8859-1"?> 2. <note> 3. <to>Tove</to> 4. <from>Jani</from> 5. <heading>Reminder</heading> 6. <body>Don't forget me this weekend!</body> 7. </note>
In the above example line 1 is the XML declaration. It states the XML version and the character set used within the document. Line 2 states the root node of the document, it is basically saying to the application that will read the document that the following is a note. Line 3, 4, 5 and 6 state the child nodes of the document (to, from, heading, body) and these are like sub headings in the note stating who the note is to, who it is from, the content of the note and the main body of the note itself. Line 7 is then the closing root node ending the XML document.
As you can see all tags in the above example have opening and ending tags meaning that this XML document is well formed.
In this next example you can see a XML example displayed as its tree structure, this example is also well formed: see link XML Tree Structure Example
XML has many uses, it can be used to store data, share data and exchange data between applications that are not compatible because it is written in plain text. This means that if you write a document in XML (say a handbook that will be used again and again) you can edit it and change it into different versions saving you having to type the document over again every time you need a new version. This makes XML a very useful and versatile language.
As stated earlier in this entry XML does not do anything by itself and an XML reader is required to read and display the XML. These pieces of software take the XML code and display it as text. There are many open source XML readers on the Internet and a free of them can be found at XML Readers.
Overall XML is a very versatile and useful language when used to send, format and display text. If used correctly it can save the user time when creating new versions of an old document which is good for use in a business.
Sources
Lecture Notes – Used as a reference to XML uses.
XML Examples – XML examples taken from W3Schools as it is a reliable source.
XML Readers – Used to show a list of available open source XML readers.
Rejected Sources
Wikipedia XML Page – Although there is some good information on XML basics on this page i rejected this source because Wikipedia is not a reliable source as anyone can edit the information on the page.
Filed under: IST 205 | Tags: IST 205 Learning Log Three - Alternatives to Apache and
Apache is the most widely available open source HTTP server on the Internet which supports the languages PERL and PHP. It is used to host websites on the Internet and includes features such as server side scripting. Apache was originally designed for Unix but now there are Windows versions as well as versions of the software for other platforms.
As Apache is an open source product it gives the user the ability to download it free of charge from Apache Download and install it on their system. Once this is done the user can write websites and host them on a private server (meaning that the web page isn’t live on the Internet) which is perfect for testing a website before it goes live. This is most effectively used when the website contains PHP coding as PHP code will only work in its intended way when it is hosted on a web server. Apache therefore gives users the ability to test websites that may have been made for private use, academic use or for business usage.
PostgreSQL on the other hand is an object-relational database management system (ORDBMS). Originally designed for Unix it now has versions compatible with all major operating systems including Windows, Linux and Mac. Again the user must first download and install the software (available at PostgreSQL Download) onto their PC but being open source this is quick, easy and free.
As stated PostgreSQL is a database management system and therefore is used mainly by businesses and large organisations to manage their database systems. PostgreSQL has many features that include database storage, data management tools, information replication as well as many other tools that can be used by business to keep their data safe and organised.
Due to its open source nature PostgreSQL is perfect for small to medium sized organisations but large scale organisations may find another alternative to PostgreSQL to be more beneficial to their needs.
There are many alternatives to PostgreSQL available on the Internet for use when managing a database. The most common alternative to using PostgreSQL is MySQL as this is the most popular open source database management system available on the Internet.
MySQL performs a lot of the same functions that PostgreSQL performs but it is also popular for use with web applications as these applications often use PHP which can be combined with MySQL. Content Management Systems also use PHP and MySQL as these are essential components to the systems running. For example WordPress and Wikipedia use PHP and the MySQL database to keep them running which have become increasingly popular as discussed in Learning Log One.
However MySQL has been criticised over the years for diverging from the SQL standard on default values although this has been improved upon in versions since Version 5.
There are many other Database Management Systems available on the Internet both open source and commercial and which one is the best for the users circumstances depends on personal preference and what it is to be used for.
As stated above Apache is the most widely available open source HTTP server on the Internet. There are many other HTTP servers available however depending on the users needs and preference. Some of these include:
- Jigsaw which is W3C’s web server which is implemented in Java.
- Cherokee which is a fast, flexible and easy to configure web server making it ideal for novices.
- XWeb which is a simple web server for Unix and Linux based operating systems which supports CGI scripts, written in Perl and C.
These are all open source alternatives which there are many, a full list of other open source web servers can be seen at this location: Open source web servers.
Most of these open source HTTP web servers perform the same functions with slight differences. Some of then are designed for use of different operating systems and the user would have to take this into account before choosing which one they wanted to go with., if any.
There are other options when choosing a web server also because there are commercial ones on offer. This involves the user purchasing some web space on the Internet and hosting their files on there. As this is a server they get all the same functions of the open source alternatives and some added bonus’ such as customer care, ect that comes with the price of purchasing. Once such commercial option is Rackspace which gives information and purchasing options for most of the main operating systems.
The down side of commercial web servers is that unlike open source web servers (where the user does not have to be connected to the Internet as files can be hosted locally) the user will have to be connected on the Internet to be able to upload and host files, ect.
Overall in the end which DBMS or web server to choose is based upon the users preference and what the application is going to be used for.
Sources
http://www.devx.com/dbzone/Article/20743/1954 – I used this site to get some criticism of MySQL.
http://www.debianhelp.co.uk/apachealternatives.htm – I used this to simply provide a list of alternative HTTP open source web servers.
http://en.wikipedia.org/wiki/MySQL – Used to get a basic starting point for MySQL
http://www.rackspace.co.uk/?ref=google&catid=business&kwd=commercial_web_hosting – Used as a commercial alternative to Apache
Sources Rejected
http://en.wikipedia.org/wiki/MySQL – While I looked at Wikipedia for a general starting overview of MySQL I didn’t use it as a source to right my findings as Wikipedia can be written and edited by anyone and therefore it is not a totally reliable source.
A blog is basically a website that is maintained and edited by a single individual. Blogs are most commonly used as online diaries where the user can keep uploading new entries to their blog to share their thoughts. A blog is normally hosted by a third party such as WordPress and Thingamablog although there are many other blog hosting websites available free of charge.
WordPress allows the user to set up an account online and then write, preview, save, publish and edit their blog dynamically online meaning it is quick, easy and once the user publishes their new blog entry it is hosted on the Internet immediately.
Thingamablog however is slightly different as it offers much functions. First of all the user must download the free software from the website and install it on their PC. Once this is done they set up an account and blog using the provided wizard and then they are ready to start publishing their blog. This is where Thingamablog differs from other blogging software as it allows the user to easily maintain multiple blogs while managing thousands of entries, write entries offline and post entries to their blog remotely via email. These are just some of the features on offer from Thingamablog and all the features it provides can be seen at http://thingamablog.sourceforge.net/.
Despite there being many choices on the Internet when it comes to which blogging software to go with they all provide the same basic structure which is the ability to write and post your own personal blog on the Internet.
Blogs also have many uses and are not just restricted to online diaries as blogs can also be used to store and show photographs, music and video meaning that many professionals can make use of blogs as a mean of sharing their work to the world free of charge.
Academics can also make use of blogs in their studies as they can be used to write essays and Logs showing their progress throughout their studies and providing evidence of their work.
A blogs main tool however is the fact that it is never completed. This is due to the fact that new entires can always be added to the blog therefore extending it. Even if a user left their blog untouched for a certain period of time it would not be ‘completed’ as they could always go back and edit it in the future. It is this ability of the blog that has made it so popular in today’s society and so well used by individuals, students and businesses alike.
Sources
WordPress – http://www.wordpress.com
Thingamablog – http://thingamablog.sourceforge.net/
Filed under: IST 205 | Tags: IST 205 Learning Log One - Content Management Systems.
A content management system is simply a system that is used to manage the content of a website. Content management systems can be used to manage files, media, audio, electronic documents (such as e-books, web journals and RSS feeds) and web content such as blogs which can be used to manage text, images, audio, video and animation.
A content management systems (CMS) main purpose is to make the files on the system available across networks or across the web. This makes a CMS very useful to large organisations that need to share large numbers of files between its employees. A company could use a CMS to store its files in an archive sort of manner while keeping all the files organised. It could also be used to share files easily across the organisation and using a CMS on a server based system further broadens the uses to the organisation when sharing files. CMS can also be used for personal use also because since most CMS feature a web content system it means that individuals can use a CMS to store personal files and store them on the web so they can gain access any where they want to.
A CMS is mainly wrote using PHP and HTML which means that the web functions of a CMS are very customisable meaning that a user can change the interface they and other users see which makes it good for organisations and individuals alike because they can change the look of the site to their personal preferences. Also because it is wrote in this way it means that novices can change simple things such as appearance and more skilled users can go and change the CMS in any way they wish if they know the coding to use. This makes CMS’s very accessible and usable for any skill level users. This makes them extremely web usable which is good seeing as blogging (one of the main uses of a CMS) has become a very popular method to keep journals with a lot of the public using web blogs to keep a journal.
While I was doing this blog I tested a CMS called CMsimple which is a simple content management system used for small commercial or private sites. When I was testing CMsimple however I did find that for some unskilled users editing the CSS to change the appearance of their blog could be quite difficult and could be completely broken if somethoing went wrong. However due to the popularity of the software there are many sites and forums on the Interent which can be used by users with such problems to find fixes to their particular problem which makes CMsimple even more usable as any problems that may arise can be fixed with the help of other users.
There are many CMS available for people to use and many of them are open source meaning they are completely free. One of the most commonly used and most popular is the Wiki system utilised by wikipedia and wikimedia.
Overall a CMS is an exellent way to share and store files and can be succesfully used by organisations and individuals alike. With the current populatiry of such sites as wikipedia and the new trend in posting online web journals CMS are being more widely recognised and utilised. However despite this there are still many members of the public that do not know CMS exist. With the rise in use and popularity of CMS however in time many more people will hear of them resulting in more organisations utilising them efficiently and more individuals using a CMS to create web journals or store personal files in an easy to access location.
