Capturing Data

How can data be captured?

Data can be captured by a computer in many forms, these include:
- Forms
- OMR (Optical Mark Recognition)
- OCR (Optical Character Recognition)
- Sensors
- Barcodes
- Data Mining

Forms

Collect user input
Organise data in structured format
Common in web applications

a-data-capture-form A data capture form

OMR (Optical Mark Recognition)

Detects marked areas on paper by using a special machine to read the marks
Used for exams, surveys, lottery tickets
Automates data collection and entry

an-omr-form-being-filled-in An OMR form being filled in

OCR (Optical Character Recognition)

Converts printed or handwritten text into digital format
Useful for digitising documents
Assists in searching and editing text

Sensors

Devices that detect and respond to changes in environment
Convert physical signals into digital data
Facilitates automated data collection and real-time monitoring
Used in various applications:
- Temperature sensors
- Pressure sensors
- Proximity sensors
- Light sensors
- Motion sensors
- Humidity sensors
- Gas sensors
- Force sensors
- Acoustic sensors
- Magnetic sensors


Different Types of Sensor

Barcodes

Machine-readable representation of data using parallel lines of varying widths and spacings
Commonly used for tracking items, inventory management, and point-of-sale systems
Two main types:
- 1D (One-dimensional) barcodes: represent data using parallel lines (e.g. on products in shops)
- 2D (Two-dimensional) barcodes: use geometric patterns like squares, dots, or hexagons to store data (e.g. QR code)
Advantages of Barcodes: - Fast and accurate data entry - Reduces human error

barcode-scanner A Typical Barcode Scanner

Data Mining

Process of discovering hidden patterns, correlations, and insights from large datasets
Involves techniques and algorithms from fields like machine learning, statistics, and artificial intelligence
Supports decision-making by transforming raw data into valuable information
Applications of data mining:
- Marketing: Customer segmentation, market basket analysis, and targeted advertising
- Finance: Fraud detection, credit scoring, and portfolio management
- Healthcare: Disease prediction, patient clustering, and drug discovery
- Manufacturing: Quality control, predictive maintenance, and supply chain optimisation
- Telecommunications: Network monitoring, customer analysis, and service improvement

Selecting Data

Query By Example (QBE)

User-friendly method for constructing database queries using a visual interface
Allows users to search for data by providing an example of the desired output
Key Features:
- Visual representation: QBE uses a grid or form-based interface, where users can enter criteria in columns representing database fields
- Intuitive: Users don’t need to learn complex query syntax, making it accessible for non-technical users
- Flexible: Allows for simple to complex queries, including filtering, sorting, and joining multiple tables
How QBE Works:
- Users enter criteria in the appropriate columns or fields in the QBE grid or form
- The QBE system translates the user’s input into an equivalent SQL query or other query language
- The query is executed against the database, and the results are displayed to the user
Common Query Operations:
- Filtering: Users can specify conditions or criteria in the QBE grid to retrieve specific records (e.g., all customers from a particular city)
- Sorting: Users can indicate the desired sorting order for the results (e.g., ascending or descending by last name)
- Joining: Users can combine data from multiple related tables by specifying relationships between the tables in the QBE grid
- Aggregation: Users can perform calculations or summaries on the data (e.g., counting the number of records, calculating averages, or summing values)

Benefits and Drawbacks of Query By Example (QBE)

Benefits	Drawbacks
Easy to learn and use, even for non-technical users	Less powerful and flexible than SQL for complex queries and data manipulation
Visual interface makes it simple to understand and modify queries	May not support advanced database features, such as stored procedures or triggers
Provides a more accessible way to perform database searches compared to writing SQL queries	Can be slower than SQL queries for large datasets or complex operations

Managing & Exchanging Data

Managing data

After a database has been created, there must be easy ways of being able to manage the data, this includes:
- Add new data
- Edit/modify existing data
- Delete data
This can be achieved by:
- A database manipulation language (DML) such as SQL
- Built in facilities of a Database Management System (DBMS)

Exchanging data

CSV (Comma Separated Values)

Simple data exchange format
Stores tabular data in plain text
Uses commas to separate values
Widely supported and easy to parse

Employee ID,Name,Department,Salary
101,Alice Johnson,Marketing,65000
102,Bob Smith,Engineering,92000
103,Charlie Brown,Sales,58000

JSON (JavaScript Object Notation)

Lightweight data interchange format
Human-readable and easy to analyse
Uses Key-value pairs
Common in web applications

[
  {
    "Employee ID": 101,
    "Name": "Alice Johnson",
    "Department": "Marketing",
    "Salary": 65000
  },
  {
    "Employee ID": 102,
    "Name": "Bob Smith",
    "Department": "Engineering",
    "Salary": 92000
  },
  {
    "Employee ID": 103,
    "Name": "Charlie Brown",
    "Department": "Sales",
    "Salary": 58000
  }
]

EDI (Electronic Data Interchange)

Standardised electronic communication method
Transfers documents and data between businesses
Reduces paper usage and manual processes
Streamlines transactions and increases efficiency

APIs (Application Programming Interfaces)

A set of protocols that allow different software applications to communicate with each other
Enables developers to integrate different services and functionalities into their applications
Facilitates data exchange between applications and platforms
Can be RESTful (Representational State Transfer), SOAP (Simple Object Access Protocol), or other types
Advantages of APIs:
- Encourages code reuse and modular programming
- Simplifies application development by providing pre-built functionalities
- Facilitates seamless integration of different services
- Promotes innovation by enabling developers to build upon existing technologies

Memory sticks

Portable storage devices, also known as USB flash drives or thumb drives
Use flash memory to store and transfer data between computers and other devices
Connect to devices via USB (Universal Serial Bus) port

Benefits and Drawbacks of Memory Sticks

Benefits	Drawbacks
Easy to use: Plug-and-play functionality with no need for additional software	Limited storage capacity compared to external hard drives
Portable: Compact size allows for easy transport and storage	Data loss risk due to physical damage, loss, or theft
Durable: No moving parts, making them resistant to physical damage	Slower transfer speeds compared to other storage solutions
Compatible: Widely supported across different operating systems and devices

Email

Electronic communication system used for exchanging messages and files between users
Requires internet access and an email account with an email service provider

Benefits and Drawbacks of Email

Benefits	Drawbacks
Fast: Allows for near-instant communication across the world	Limited file size: Most email service providers impose restrictions on attachment sizes
Convenient: Accessible on various devices, including computers, smartphones, and tablets	Security risks: Vulnerable to phishing attacks, spam, and data breaches
Organised: Stores and organises messages in folders, such as Inbox, Sent, and Drafts	Privacy concerns: Email messages and attachments can be intercepted, read, or modified by unauthorised parties
Versatile: Supports the attachment of various file types and sizes	Reliability: Delivery issues can occur due to server problems, incorrect email addresses, or spam filters

CS Notes

Explorer