Paper 2 Unit 6

Question 1

What is data?

Answer 1

Data refers to raw facts, observations or measurements that have little meaning on their own

Question 2

What is information?

Answer 2

Processed and organised data that has meaning and context. It is derived from data through interpretation, analysis and contextualisation.

Question 3

What is knowledge?

Answer 3

Knowledge goes beyond information and represents the understanding, insights and expertise gained from information and experience.

Question 4

What is human readable data?

Answer 4

Unstructured data like a block of text that can only be interpreted by humans

Question 5

What is machine readable data?

Answer 5

Structures data like a set of instructions that can be processed by computer programs

Question 6

What is big data?

Answer 6

Large, complex, and layered groups of data that can be analysed to spot patterns and trends

Question 7

Define a data type.

Answer 7

The way data is stored (string, integer, float etc)

Question 8

What is data wrangling?

Answer 8

The process of transforming a raw data form into a desired format suitable for purpose

Question 9

Name the stages of data wrangling

Answer 9

Discover, structure, clean, enrich, validate, share

Question 10

Why do organisations need data?

Answer 10

To analyse market trends to identify patterns and inform decisions, system performance analysis, user monitoring, targeted marketing, inform decision making, assess threats and opportunities

Question 11

How is data generated?

Answer 11

Human input, AI, sensors, Internet of Things, Transactional data

Question 12

Name different data formats

Answer 12

ASCII, CSV, fixed width text file, XML, JSON

Question 13

What are the benefits and drawbacks of ASCII?

Answer 13

Benefits: Standard format for all computer systems, communicate using standard English alphabet
Drawbacks: Limited number of characters, replaced by Unicode which contains other alphabets and symbols so can be more widely used

Question 14

What are the benefits and drawbacks of CSV?

Answer 14

Benefits: Common format understood by most applications
Drawbacks: Format is delimited and it is possible to use other delimiters other than the comma, tab is common making TSV widely used

Question 15

What are the benefits and drawbacks of Fixed Width data formats?

Answer 15

Benefits: For very large data files it’s easy to calculate the location of data to retrieve it since the length is fixed
Drawbacks: Fixed sizes for fields, padding character and alignment need to be known before data can be retrieved accurately, needs to be carefully planned before setting up and saving data

Question 16

What are the benefits and drawbacks of XML?

Answer 16

Benefits: platform dependent so can be used on any system, supports Unicode so can cope with data, displayed in a GUI using HTML
Drawbacks: Requires a series of complex tags to store the data making files large

Question 17

What are the benefits and drawbacks of JSON?

Answer 17

Benefits: Compact format based on JavaScript that can be used on most systems, good and reliable for website-to-website data transfer, many programming languages support JSON
Drawbacks: No error handling for JSON calls, security issues with data transfers if it is being hosted on a vulnerable website so it is open to hacking

Question 18

What are the differences between file-based directory structure and dictionary-based data structures?

Answer 18

File-based: defines the structure and types of data stored, each application defines and manages own data, data should be consistently structured to maintain access to different processes, different file formats can make data incompatible, data can be duplicated, analysing data can become complex since formats need to be rationalised.

Dictionary-based: typically hierarchal, easier to locate data, set of keys to a value, set of keys are ordered making structure more logical and searching more efficient.

Question 19

What are the stages of data wrangling?

Answer 19

Discovery- becoming familiar with the data and understanding it so patterns can be identified
Structure- data restructured into single format after coming from different sources with additional items of no value being removed
Clean- errors identified and fixed, outliers, null values and duplicates removed, format standardised, typos fixed, measurements standardised and data validated
Enrich- existing data from internal or third-party added to fill gaps and enhance set
Validate- quality of data validated for quality, consistency, accuracy, security and authenticity
Output- data ready to be published and used

Question 20

What are the core functions of a data system?

Answer 20

Input, Search, Save, Integrate, Organise, Output, Feedback loop

Question 21

Why is maintaining data important?

Answer 21

Making sure data entry is accurate is not enough, regular check need to be carried out to update important data e.g by contacting customers regularly to check their data is correct

Question 22

How can data be visualised?

Answer 22

Graphs and charts to help clarify data but the scales and choice of graph can be confusing and misleading, data tables to provide rapid and easy access to enable stakeholders to compare information but they need to be labeled accurately, reports show data in an accessible format to assess the performance of a business but a consistent format is needed so comparisons can be made, infographics represent data graphically with minimal text for an easy-to-see overview however they can sometimes lack detail

Question 23

What is the purpose of business intelligence software?

Answer 23

To retrieve and analyse data to inform decision making. The applications can provide information that a business can use to inform decisions about long-term strategic decisions

Question 24

What is the purpose of financial planning and analysis?

Answer 24

To support the financial aspects of the business including financial planning, setting budgets and forecasting future performance including profits

Question 25

What is the purpose of customer relationship management?

Answer 25

To manage relationships with existing and potential customers and to make it easier for the customer-facing employees to build relationships, steamline processes, improve customer service and increase profits. Software can gather data from various sources, track customer interactions, identify any trends and use the information to inform decisions

Question 26

What are the aspects of data models?

Answer 26

Conceptual (high-level needs, main concepts and relationships) Logical (description of model in terms of structures to define implementation) Physical (how the model should be implemented using a specific database management model) Hierarchal (relationships between tables, records and fields in a tree-like format) Relational (relationships between tables, records and fields in terms of primary and foreign keys)

Question 27

What are entity relationship diagrams (ERDs)?

Answer 27

Formal diagrams that represent the relationships between entities in a database to convey the design objectives

Question 28

What relationships can be represented in ERDs?

Answer 28

One-to-one One-to-many Many-to-many

Question 29

What diagrams does UML use to explain interactions and links?

Answer 29

Class- facts about an entity and the ways to access the facts Use case- describe what is going on in the system Communication- show how objects combine and carry out a task Activity- show various processes in a system Sequence- how objects interact with each other

Question 30

What are the 6 V's of big data?

Answer 30

Volume- the size of the data being analysed, more data= more accurate results Variety- a wide variety of data can result in unexpected results and be used to create different uses for the data Variability- the measure of how quickly and by how much the data are changing Velocity- the measurement of the temporary value of the data and how quickly the data should be processed to have any value Veracity- the quality of the data, the origin and any conflicting information to determine if the data is authentic Value- how effective and useful the data is

Question 31

What is validation?

Answer 31

Checking that the data is reasonable within a realistic range and complete

Question 32

What validation techniques can be used?

Answer 32

Presence check, length check, type check, format check, range check, combination check

Question 33

What is verification?

Answer 33

Checking that the data is copied correctly (not that the data is correct as this could be that the source is incorrect)

Question 34

How can data be verified?

Answer 34

Enter the data twice so the two copies can be compared to ensure they are correct. Data redundancy can be used to store the data multiple times. Analysis can be carried out on the redundant data to ensure it is consistent and that it has not been recorded in a different format or has been changed or been recorded differently

Question 35

How can data be collected by an organisation and what are the costs associated with them?

Answer 35

As a by-product of everyday activities From external sources As a result from market research Costs: Entering data is time consuming and could involve hiring extra staff 3rd party data may be less reliable and may need to be cleansed Phrasing questions to solicit a response in market research could give unreliable results Data may be passed between department in the organisation which could lead to it being too old to be useful or being different or changed in some way

Question 36

What is the difference between data lakes and data warehouses?

Answer 36

Data lakes are vast stores of raw data that are not in any specific format or for a defined purpose whereas data warehouses store structured data that have been processed for a specific purpose

Question 37

How can raw data be processed?

Answer 37

Data mining- analysing raw to data to find patterns and trends which can be used to inform decisions, identify risks, cut costs, increase income and improve customer relations Data reporting- providing the organisation with an overview of the current situation based on an analysis of past data and the current situation to identify future actions but the facts are presented without any context

Question 38

What are the different types of metadata?

Answer 38

Descriptive- enable identification and selection for a resource Administrative- enable the management of a resource including any restrictions Structural- used when processing data and include any relationships or structural features

Question 39

How can user access entitlements impact the organisation and stakeholders?

Answer 39

Authorised users are given privileges to limit what they can access and edit in line with their role. The organisation will include a set of rules about how data can be access and used based upon the access rights given

Question 40

What is the role of an Application Programming Interface (API)?

Answer 40

It is a way for multiple applications to communicate with each other as it enables data to be transmitted from one app to another. The user sends a request for data and the server responds, data is exchanged in an agreed format. A web API processes data between a web server and browser

Question 41

Why is API authentication and monitoring crucial to the security of links between different software?

Answer 41

Authentication tokens are checked to make sure the user is who they claim to be and has access rights to the API and API keys and codes are sent with a request to authenticate the application and the user and are used to track interactions and how the interface is used to prevent abuse or malicious use of the API

Question 42

What is the difference between data at rest, data in motion and data in use?

Answer 42

Data at rest is when the data are stored but not being moved Data in motion are data that are moving from one location to another through the internet into storage or internally from one device to another. Data is most vulnerable to security breaches when it is in motion Data in use is data that is currently being processed or used