[Free help] Does anyone have any issues with IT Apps? I can (hopefully) help

[Orson]

This seems like  good enough question thread..

Can someone help me with understanding Question 9 from the 2012 VCAA Exam. I understand how to properly get it into 3NF but I'm at at loss trying to understand how normalizing it in each form ensures data integrity. I've looked through the examiners report and the Mark Kelly postmortems but I'm kind of getting lost in it all. Also for a question like this, do we have to show each step of the normalization or just the final form?

Any help would be great!

NF3: Fields included in tables should only be relevant to the primary key

"Fiels that aren't  relevant to the primary key must be removed. Non-key fields must give information about the key and nothing but the key. In this case, that means removing "d_carRate" and "d_totalFees" from the drivers table.

This will improve efficiency as only relevant information is being processed. "d_carRate" and "d_totalFees" can be calculated in a query, and reports can be made after"

I hope this helps!

[Floatzel98]

NF3: Fields included in tables should only be relevant to the primary key

"Fiels that aren't  relevant to the primary key must be removed. Non-key fields must give information about the key and nothing but the key. In this case, that means removing "d_carRate" and "d_totalFees" from the drivers table.

This will improve efficiency as only relevant information is being processed. "d_carRate" and "d_totalFees" can be calculated in a query, and reports can be made after"

I hope this helps!

Thanks Orson. What would you say about 1NF and 2NF then?

[ITTeacher]

I'm at at loss trying to understand how normalizing it in each form ensures data integrity.

Data integrity is related to accuracy. If the data is accurate, we can trust it.

Separating lists of data enables us to more-accurately sort and filter data. (e.g. separating street address from suburb lets you filter for a particular suburb, whereas you couldn't do that before)

Including a primary key enables us to more-accurately retrieve the details of a record that may share a data value. (e.g. filtering LastName = "Smith" may retrieve multiple records, whereas filtering MemberID = "SMI0001" will retrieve the exact Smith we were looking for)

Separating tables removes redundant data, which means that the chances of updating anomalies appearing is reduced, making our data more-accurate (e.g. Member SMI0001 changes his address, if redundant data exists, the address needs to have many instances updated, whereas if there is no redundant data the address only needs to be updated once)

Moving calculated fields from the table into a query will change the calculation from being a manual calculation to an automated calculation - more-accurate (e.g. TotalFee would need to be calculated by the database operator as it's stored in the table - prone to human error. Whereas if it's calculated in a query, it can be automated using the Car Rate and Years Worked fields.)

In addition, you could also change the Years Worked field to Employment Date, which would be used to calculate Years Worked. This too would remove human error when updating, as when the data is stored in Years Worked it would require the Database Operator to change the Year for each record as the Driver completes another year of driving, a tedious task that would be prone to human error. 

Also for a question like this, do we have to show each step of the normalization or just the final form?

Displaying your changes as a Data Structure Diagram would comprehensively show the transition from 1NF to 3NF in that you've shown the separating of fields, the primary keys & foreign keys, the relationships, the separating of tables and the removal of calculated fields.

[Orson]

Data integrity is related to accuracy. If the data is accurate, we can trust it.

Wow! Cheers mate...I learned a lot!

I just want to clarify some things:
- Doing all this normal form stuff is to increase accuracy, and decrease data duplication. This will increase accuracy as the user only needs to enter the data into the system once, and it reduces the chance of incorrect data entry significantly.
- Manipulating the system according to 1NF, 2NF and 3NF is just to get the data to its simplest form, and to always reuse data (and not dupe everything...thus more accurate yadda yadda).

Thanks mate! Could you please read my comment and let me know if what I said was correct? I copied my answer (for which I gave myself full marks). How would I improve?

[Floatzel98]

Thanks heaps guys! Really clears things up.

[Orson]

Thanks heaps guys! Really clears things up.

All good! Does anyone know how deep we need to be with Laws and ethics and all of that?

[ITTeacher]

Wow! Cheers mate...I learned a lot!

I just want to clarify some things:
- Doing all this normal form stuff is to increase accuracy, and decrease data duplication. This will increase accuracy as the user only needs to enter the data into the system once, and it reduces the chance of incorrect data entry significantly.
- Manipulating the system according to 1NF, 2NF and 3NF is just to get the data to its simplest form, and to always reuse data (and not dupe everything...thus more accurate yadda yadda).

Thanks mate! Could you please read my comment and let me know if what I said was correct? I copied my answer (for which I gave myself full marks). How would I improve?

Which question were you answering? Q9 from 2012? You'd require 3 different points.

I'd suggest that you addressed three of the changes that you made to the database.

[ITTeacher]

All good! Does anyone know how deep we need to be with Laws and ethics and all of that?

Generally, you need to know the exact name of the law, including the year.

You should be able to identify that:

Privacy Act 1988, Information Privacy Act 2000 and Health Records Act 2001 are all about safeguarding sensitive data and information.

Privacy Act 1988 protects data relating to: Credit worthiness, Tax File Numbers, any Australian Government Organisations and any Private Organisations who turnover > $3 Million per year.
Information Privacy Act 2000 protects data relating to: Victorian Government Organisations
Health Records Act 2001 protects data relating to: Victorian Health Organisations

Copyright Act 1968 protects Intellectual Property from being copied.

Spam Act 2003 stops unsolicited electronic communication from organisations.

Charter of Human Rights and Responsibilities Act 2006 protects people's Privacy and Reputation, Freedom of thought, conscience, belief and religion, and Freedom of expression.

Regarding Ethics you need to be able to identify the stakeholders in a scenario and consider the impact on each of the stakeholders in the scenario. You should also know how to resolve any conflict or tension.

[Acid]

This seems like  good enough question thread..

Can someone help me with understanding Question 9 from the 2012 VCAA Exam. I understand how to properly get it into 3NF but I'm at at loss trying to understand how normalizing it in each form ensures data integrity. I've looked through the examiners report and the Mark Kelly postmortems but I'm kind of getting lost in it all. Also for a question like this, do we have to show each step of the normalization or just the final form?

Any help would be great!

Normalising it ensures the data is consistent. So if you update a record in one table, the record's details will automatically change in another. This ensures:
-There is no repetition/redundancy, hence less storage space is required.
-Queries process faster.
-Keeps data up-to-date, as it is changed throughout the database, and not just one table. So changes only need to be made in one place, rather than multiple tables. This allows organisations to abide by privacy legislations too.

In a question like the one you mentioned, showing all three forms in necessary. If you're still confused, look at the space given-  it's a pretty good indicator of how much working is required.


Edit: oops, didn't see the query had been answered :p

[Orson]

I know this is a lot to ask. But has someone compiled a rough list of what they are going to memorise and whatnot?

This is what I've got so far...I'm not sure what to add. As you can see...I'm really not sure.

- All Laws
- Normalisation rules
- Definitions of router, modem, web server
- SSL, TCP-IP

Thanks!

[Acid]

I know this is a lot to ask. But has someone compiled a rough list of what they are going to memorise and whatnot?

This is what I've got so far...I'm not sure what to add. As you can see...I'm really not sure.

- All Laws
- Normalisation rules
- Definitions of router, modem, web server
- SSL, TCP-IP

Thanks!

Remember, the study design is your best friend. :p

[Orson]

Remember, the study design is your best friend. :p

I'm not sure if I'm looking at the right thing...it doesn't seem very helpful...

http://www.vcaa.vic.edu.au/Documents/vce/infotech/InformationTechnologySD-2011-2014-web.pdf

Is this the right one? It says 2011 - 2014...

[Acid]

I'm not sure if I'm looking at the right thing...it doesn't seem very helpful...

http://www.vcaa.vic.edu.au/Documents/vce/infotech/InformationTechnologySD-2011-2014-web.pdf

Is this the right one? It says 2011 - 2014...

Yup, it's the right one. Hmm, I think it's pretty helpful tbh. It covers everything, so if you know 100% of it, you're good to go. I use it as my check list lol

[maybesortof]

Hey guys so I've got a question from the 2009 VCAA exam, the answer says Privacy Act 1998 whereas I put down Information Privacy Act 2000. Is the reason why it's Privacy Act 1998 because the question doesn't involve government and hence is not fully relational to the Information Privacy Act 2000?

I don't know how, or if you even can, attach pictures here so here's the image on imgur

[maybesortof]

Also another question, could someone please differentiate between Layout Diagrams, Mock-ups and Story Boards?

Thanks