1. Define the term Database Management System.
2. Aware of the different components of a Database Management System.
3. Recognise the difference between logical and physical views of database data.
4. Define three database models and outline their basic features.

1. A database management system (DBMS) is a program that provides access to all data in the database. It sits between all the programs and the stored data. A DBMS manages security and user access, maintains the integrity of stored data, and recovers information when the system fails. A range of tools provide users with the ability to perform functions such as maintain data, search, sort, display and print.
2. Four components of a DBMS are:

   Data Model

   The data model defines the way data are conceptually structured. Examples include the hierarchical, network & relational models.

   Data Definition Language (DDL)

   A set of statements defining what types of information are in the database and how they will be structured, is known as the DDL. It acts as a link between between the logical and the physical views of the database. A DBMS user defines schemas and sub-schemas with the DDL. The schema is the logical description of the entire database and the listing of the data items and the relationships among them. A sub-schema is the specific set of data required by an application / user group.

   Data Manipulation Language (DML)

   To query the contents of the database, the DML is used. It allows users to retrieve, sort, display and delete the contents of a database.

   Data Dictionary

   Besides listing the standard data name and aliases for the element, the dictionary lists the names that reference this element in specific systems and identifies the individuals, business functions, applications, and reports that use the data element. Data dictionaries are advantageous for organisations in several ways including reduced data inconsistency, faster program development, and easier data modification.

3. Users from all functional areas should assist in creating the logical design to ensure that their needs are identified and addressed. The logical design shows an abstract model of the data structures and arrangements to meet an organisations information needs. Identifying relationships among different data and grouping them is an integral part of developing the logical design.

   Starting from the logical design, the physical design adds fine tuning for performance and cost considerations. For example, improved response time, reduced storage space, lower operating costs, etcetera.

4. The structure of the relationships in most databases follow one of three models:
   1. Hierarchical - Early mainframe DBMS packages used a treelike structure. From the single root element, one can follow the branches of one-to-many relationships to reach the desired data element.
   2. Network - This model allows many-to-many relationships. Unlike the hierarchical model, the network model can access a data element by following one of several paths.
   3. Relational - Data elements are stored in simple tables, each record having a unique primary key. Inclusion of a foreign table’s primary key, a foreign key, can bind the relation.
      

   A data model is a diagram of the data entities and their relationships. Data modelling usually involves understanding specific business problems and analysing the data and information to deliver a solution. With Entity-Relationship (ER) diagrams, individuals building a database have a blueprint to ensure relationships among data entities are correctly structured. ER diagrams also ensure that application programs are developed consistent with business operations and user needs.

1. Define the term database.
2. What is an attribute? How is it related to an entity?
3. What is data redundancy? Why is it a problem?
4. How would you describe the traditional approach to data management? How does it differ from the data base approach?

1. An organised storage of logically related records could describe a database. This integrated collection of data is independent of application programs using the data.
2. A data field represents an attribute [a characteristic or quality] of some entity [object, person, place, etc]. For example, an employee’s salary is an attribute that is a typical data field used to describe an entity who is an employee of a business. Thus an attribute is an identifiable part of the whole, that is the record.
3. In a traditional approach to data management, data redundancy is among many of the problems. For example, a school will have student data in an enrolment fees file, in a class roll file, and a grades assessment file; all independently reproducing the same data. This repeated information is both a waste of storage space; and leads to inconsistent data, with no way of knowing which is correct.
4. The traditional approach is not integrated. Every department of information has its own independent file, which often duplicates some of the data stored in other departments. The database approach integrates and rationalises the data into a centralised storage system. Data redundancy, data isolation (difficulty accessing data from different applications) and data inconsistency are minimised in a database approach. Additionally, data updates are easier because the data is stored in one accessible location. The drawbacks of a database management system (DBMS) include the cost of purchase and operation environment as well as any specialist staff required. If security is breached, more data is accessible to a trespasser. Also a failure in the DBMS will affect all application programs depending on it.

1. How would you distinguish data and information? Information and Knowledge?
2. Identify at least 6 characteristics of valuable information.
3. What is a computer-based information system? What are its components?

Data are the raw facts. For example the grocery store manager’s list of every item sold today. Alone it is rather useless, trivial in fact. Comparing the actual total sales with the planned sales, gives added value and meaning, becoming information. Knowledge is an awareness and understanding of a set of information, and ways that information can be made useful to support a specific task or reach a decision. (Stair and Reynolds, 2003)

Accuracy, completeness, economical, simplicity, timeliness, and flexibility are just 6 characteristics of valuable information.

An information system is a set of interrelated elements or components that collect [input], manipulate [process], and disseminate [output] data and information, and provide feedback mechanisms to meet an objective. (Stair and Reynolds, 2003) Thus a computer-based information system (CBIS) is one that inputs, processes, and outputs information using computer technologies. Components of a CBIS fall into groups of hardware, software, telecommunications, databases, people and procedures.

Stair, R.M., & Reynolds, G.W., (2003). Fundamentals of Information Systems, 2nd Edition.Thomson Learning.

1. What is the Organisation?
2. What are the Functional Areas?
3. What are the Business Processes in 1 of the functional areas?

http://www.whitehorse.vic.gov.au/Page/page.asp?Page_Id=1222&h=0 takes us to the City of Whitehorse. There are 4 main functional areas: Corporate Services, City Development, Human Services, and Infrastructure. Business Processes within the Human Services area are: Community Development, Home & Community Care, Health & Family Services, and Arts & Recreation Development.

As an illustration of the information you give away when you are browsing online, go to one of the following websites:

• http://network-tools.com/analyze/
• http://centralops.net/asp/co/BrowserMirror.vbs.asp

This is just a sampling of the large amount of information that can be collected from you. This information can be used in many ways.

For marketing purposes, information such as: browser type; what sites you have visited and your favourites links (which can yield information on your browsing habits); what type of sites you visit (which can indicate what hobbies you have, and where you work - including what field); what type of computer you are using etcetera; can all then be used to target ads to you.

However, someone can use this information for a more malicious intent. If someone can get information on what browser you are using, and what operating system, they can see what security vulnerabilities you are susceptible to and can ‘attack’ your machine using this information – this is merely one example (and there are countless other ways) the information you give away can be maliciously used.

Perhaps it is a good thing that the next release of Firefox will have a porn mode. Check out the current security features if you’re bored. Oh, and by the way, if you are still using Internet Explorer, in all likeliness, you’ve been attacked and just don’t realise it. Take a read of the post by Brian Krebs from January 4, 2007 titled Internet Explorer Unsafe for 284 Days in 2006.

Firefox users who can’t wait for 3.1 (it’s available in Beta at this time), or you need another surf of those porn sites, then perhaps get some privacy and security add-ons in the meantime. They might slow down the onslaught of Viagra, penis enlargement and breast implants spam arriving in your inbox.

In one of my new units of study, NET26 Cyberanalytics, we’ve just finished a survey design. This next task is to report on website traffic statistics. The following is my effort at a simple exercise to create pretty pictures from the raw log data.

Since every man and his dog can publish anything on websites, we may question the accuracy of that content. Following the net.Tutor tutorial on Evaluating Web Sites, there are 6 points to consider in order to infer a reliable source.

1. Purpose

Is it an advocacy, commercial, or reference site?

2. Author

Check that both the author and publisher have credibility on the topic. See the net.TUTOR: Using Online Resources to Check Authority or perhaps try the following Firefox add-on.

Who Is This Person? by Ted Rheingold
Highlight any name on a web page and see matching information from Wink, LinkedIn, Wikipedia, Facebook, Google News, Technorati, Yahoo Person Search, Spock, WikiYou, ZoomInfo, IMDB, MySpace and more…

3. Content Bias / Balance

In order to understand the need for this check, I’ll re-iterate the quote here.

Most of us have biases, and we can easily fool ourselves if we don’t make a conscious effort to keep our minds open to new information. Psychologists have shown over and over again that humans naturally tend to accept any information that supports what they already believe, even if the information isn’t very reliable. And humans also naturally tend to reject information that conflicts with those beliefs, even if the information is solid. These predilections are powerful. Unless we make an active effort to listen to all sides we can become trapped into believing something that isn’t so, and won’t even know it.
A Process for Avoiding Deception, FactCheckED.org

Good website sources on controversial topics should present a balance of both pro and con viewpoints, together with arguments supported and documented.

4. Coverage

To cross-check similar sites, try the Google related search, for example related:meyerweb.com

5. Timeliness

For researching time-sensitive topics, consider the age of, and how up-to-date any sources are.

6. Recognition

Just like the related search, Google provides a link search to find other sites linking to the source in question. For instance, link:meyerweb.com. Public bookmarking sites, such as del.icio.us, can indicate popularity with related tags. Technorati authority defines the number of blogs linking to a website in the last six months. For very new articles there may not yet be any citations, but try Google Scholar. These are just some measures of recognising that the source site provides useful information.

So now we know several ways to investigate and judge whether a website is an informative and worthwhile source. Let’s do it!

Evaluation of a source slightly relevant to the NET11 unit

• URL http://meyerweb.com/eric/articles/webrev/200001.html “Print Different”
• Author Eric A. Meyer
• This blog posting is a tutorial on implementing a CSS design for the print medium. The information presented is most helpful for web designers. The site is largely authored by an individual, an advocate for promoting the use of CSS standards. I doubt that an opposing viewpoint exists, but no alternatives to CSS are mentioned in this article.

  As the author of several books on the topic, naturally he does have a vested interest in selling them. However the article above was taken from his personal site, not the separate commercial one. He is an internationally recognized expert on the subjects of HTML and Cascading Style Sheets (CSS). … Eric coordinated the authoring and creation of the W3C’s CSS Test Suite and has recently been acting as List Chaperone of the highly active css-discuss mailing list. Certainly a reputable author and publisher on the subject.

  The article is somewhat biased and barely mentions the cons. The pro arguments are detailed, but as it is a tutorial rather than a controversial topic, it is supported by many examples. In terms of coverage, there are, according to the Google related:meyerweb.com search, less than 30 other websites similar to meyerweb.com, some of which Eric plays a role in!

  Back in January 2000, the material was originally written as a professional article on http://www.webreview.com. No information has been added recently, the content may be up-to-date but the external links no longer connect - probably due to the original site’s archiving scope. Hence, as stated, one of the reasons Eric has archived these articles himself. He does promise a return to the subject once browsers increase support for more media and specific styles.

  As for recognition, delicious reveals 18 public bookmarks of the site, Google found about 2,170 sites linking to meyerweb.com, and Technorati uncovered 3,225 blog reactions.

  As one might expect in a tutorial article, it was written with a biased viewpoint. Overall though, the distinguished author has produced an excellent tutorial, supported by examples and current best practices, with ample coverage of the topic for my needs.

Finally, for my own future use, the full evaluation is overkill. The quick skim of a basic annotation will suffice to jog my memory. For external users however, an analytical evaluation is superior as it includes thorough author and content cross-checking.

First, choose the best three sources found in the previous task.
Using whatever software or tool you think appropriate, record the following information about those sites:

• URL
• author
• institution
• blurb/ summary / screen shot (this can be a direct copy of an appropriate abstract or introductory paragraph on the site: but make sure you record and reference it as such)

Again, using any useful software you have downloaded, or utilising your existing software, record this information on your computer in the way that you think will be most useful to you in terms of preparing for your third assignment (that is, in terms of how easy you will find it to access, retrieve, understand, contextualise and recall why you saved it - and with what!).

* LOG ENTRY:
Record this information in your learning log, and also detail how you saved this information, what software you used and why. (Allen, n.d.)

The previous task was a search of our choosing. Mine was a query for “winter dreaming” film screening and the best 3 sources are as follows:

1. • http://www.eucalyptproductions.com/winterdreaming
   • Stephen Curtain
   • Eucalypt Productions
   • 
     Screenshot from
     http://eucalyptproductions.com/winterdreaming

     This page is self-promoting the debut of Winter Dreaming, a film by Stephen Curtain. It includes a preview, a film synopsis, cast and crew summary, and a list of screening dates and venues for 2008. Also listed are target audiences and several potential purposes for usage of the film as an educational resource. The author, cameraman, and producer has a swag of credentials including various photographic and editorial jobs for the BBC, ABC, Australian Geographic, The Age, Wild and Rock magazines. He has works in the fragile environs of Antarctica and around t