A1 Introduction to Information Processing A2. Data Organisation and Data Control

 A1. Introduction to Information Processing

 

Learning Outcomes:

• Define Information Age and discuss the importance of information literacy in a knowledge-based society.
• How the development of technologies leads to the emergence of the Information Age, and how information can be flexibly and analytically converted into knowledge in modern society should be discussed

 

Information age

 

Large amount of information available in the internet.

Individuals have instant access to information.

Information can be flexibly and analytically converted into knowledge.

è Knowledge-based society

 

References:

https://www.igi-global.com/dictionary/information-age/14305

 

A2. Data Organisation and Data Control

 

Learning Outcomes:

• Identify data, records, fields, files and databases in the hierarchical organisation of data.
• Explain how records can be organised, stored and retrieved. State the advantages, disadvantages and applications of the two types of file access: direct access and sequential access.
• Discuss the needs of data control.
• Describe how errors can be detected by using validation and parity checking, and prevented by verification and validation

 

File organisation

• Organize by name or date with good folder structure.

 

File access

• Sequential access: e.g. magnetic tape. Data access starts from the beginning until the required information is found or till the end. Used for backup purpose as fast data access not important.
• Direct access: e.g. Hard disk. Data access is almost instant. No need to start searching from the beginning.

 

Error

• Error detection
• Validation: see below
• Parity check: parity bit added to a data. E.g. 1100001, a parity bit can be added such that the sum of all digits are even number. i.e. 11000011
• Error prevention
• Validation: see below, data rejected will not be used
• Verification: check if the data entered is the same as the source document e.g. double entry (such as enter password twice), check by another person
  
  
• Data Validation
• Check whether the input data follows the pre-set rules. E.g. data type, range of integers allowed, format of the string, range of the date entered, parity check. Users will usually be prompted to re-enter the data that confines to the rules.

 

Relevant past paper:

DSE ICT Paper 1B(SP-2017): SP 5bi. PP 5a. 2014 1a. 2015 2aii, 5dii. 2016 1d. 2017 4b.

 

References:

https://www.microsoft.com/en-us/microsoft-365/business-insights-ideas/resources/11-ideas-for-how-to-organize-digital-files

https://www.ictlounge.com/html/serial_and_direct_data_access.htm

https://www.safe.com/what-is/data-validation/

https://www.precisely.com/blog/data-quality/data-validation-vs-data-verification

https://teachcomputerscience.com/verification/

 Comprehesion-type questions

 

Learning Outcomes:

• Represent algorithms with flowcharts or block diagrams.
• Apply algorithms of counting, accumulating, swapping, searching, sorting and merging in writing programs.
• The search algorithms included are linear search and binary search.
• Construct lists, stacks and queues in terms of arrays.
• Students should be able to create and manipulate linear linked lists, stacks and queues in terms of arrays.
• Realise the importance of good programming styles.
• Students should develop the habit of using meaningful variable names, comments, annotations, space and indentation.
• Design sets of test data for program testing.
• Test data for boundary cases has been discussed in the Compulsory Part.

 

Follow a flowchart

Relevant past paper:

DSE ICT Elect B(SP-2017):  2014 1b.

 

Searching

Linear/sequential search: check the items one by one. E.g. for data structure such as queue and linked list.

Binary search:  for data sorted in an array.

 

Relevant past paper:

DSE ICT Elect B(SP-2017):  2017 4dii,e.

 

Linked lists, stacks, queues

• Linked lists: need to find an item by linear search. More flexible to add or remove an item.
• Queues: first-in-first-out. Need to use head and tail indicator.
• Stacks: last-in-first-out.

All data structure can have underflow errors/overflow errors if attempts to add items to a full list or to remove items from empty list.

 

Relevant past paper:

DSE ICT Elect B(SP-2017):  SP 2de. PP 2ab. 2012 2a. 2014 1ci,3. 2016 2ac. 2017 3ab.

CE CIT Elect A(2005-2011): 2005 4. 2006 4. 2008 2ab. 2009 3abce. 2010 1a. 2011 3a-d.

 

Good programming styles

• Use of meaningful variable names, comments, annotations, space and indentation.
• Use of constant: easy to change the value for use in other programs.

 

Relevant past paper:

DSE ICT Elect B(SP-2017):  2012 3b.

 

Test data

Useful set of test data should include:

• Valid data: normal data and extreme case
• Invalid data

 

Relevant past paper:

DSE ICT Elect B(SP-2017):  PP 3e. 2013 2e.

CE CIT Elect A(2005-2011): 2006 1c.

 

Manipulate arrays

Relevant past paper:

DSE ICT Elect B(SP-2017):  2014 2abci. 2015 3abii,iii.

 

Other questions

Relevant past paper:

DSE ICT Elect B(SP-2017):  SP 2a. 2013 4ab. 2015 4bc. 2016 3avd. 2017 4aci,di.