📘 GENERATING TEST DATA

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✅ 1. What is Test Data?

Definition: Test data is the input data used to test software applications.

👉 Simple meaning: It is the data you enter into a system to check whether it works correctly.

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📊 Example:

For a login system:

• Username: user1
• Password: 12345

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🎯 Key Idea:

• Good test data = better testing
• Helps find more bugs

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🟢 2. WHAT IS TEST DATA GENERATION?

📌 Definition:

Test data generation is the process of creating data to use in test cases.

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🎯 Purpose:

• Validate system behavior
• Check different scenarios
• Ensure full test coverage

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🔑 3. TYPES OF TEST DATA

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🔵 1. VALID DATA

• Correct input
• Expected to work

📊 Example:

• Age = 25 (valid)

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🔴 2. INVALID DATA

• Incorrect input
• Used to check error handling

📊 Example:

• Age = -5

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🟡 3. BOUNDARY DATA

• Values at limits

📊 Example:

• Range: 1–100 → Test: 1, 100

👉 🔥 Frequently asked!

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🟣 4. EDGE CASE DATA

• Extreme or unusual values

📊 Example:

• Empty input
• Very large numbers

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🧪 4. TECHNIQUES FOR GENERATING TEST DATA

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🟢 1. MANUAL TEST DATA GENERATION

📌 Definition:

Tester manually creates data.

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📊 Example:

Typing values like:

• Username = "Ali"

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🎯 Advantages:

• Simple
• Flexible

❌ Disadvantages:

• Time-consuming
• Error-prone

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🔵 2. AUTOMATED TEST DATA GENERATION

📌 Definition:

Tools automatically generate test data.

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📊 Example:

• Random number generator
• Scripts

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🎯 Advantages:

• Fast
• Large data sets

❌ Disadvantages:

• Needs tools

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🟡 3. RANDOM DATA GENERATION

📌 Definition:

Generate random values.

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📊 Example:

• Random email IDs

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🎯 Use:

• Stress testing
• Performance testing

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🟣 4. BOUNDARY VALUE-BASED DATA

📌 Definition:

Generate data based on boundary values.

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📊 Example:

Range: 1–100 Data: 0, 1, 2, 99, 100, 101

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🎯 Key Point:

• Finds maximum errors

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🟠 5. DATA SUBSETTING

📌 Definition:

Use a small portion of real data.

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📊 Example:

• Select few records from database

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🎯 Advantage:

• Realistic testing

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🔴 6. DATA MASKING

📌 Definition:

Hiding sensitive data while testing.

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📊 Example:

• Replace real names with fake ones

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🎯 Key Point:

• Ensures security

👉 🔥 Important for exams!

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🧠 5. SOURCES OF TEST DATA

• Manual input
• Databases
• Files (Excel, CSV)
• Automated tools

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📊 DIAGRAM: TEST DATA GENERATION PROCESS

Requirements → Identify Inputs → Generate Data → Execute Tests → Validate Results

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⚖️ ADVANTAGES & DISADVANTAGES

✅ Advantages:

• Improves test coverage
• Detects bugs effectively
• Supports automation

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❌ Disadvantages:

• Time-consuming (manual)
• Requires tools/skills (automated)

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🔥 FREQUENTLY ASKED EXAM POINTS

✔ Define test data ✔ Types of test data ✔ Boundary data explanation ✔ Data masking concept ✔ Techniques of test data generation

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📊 QUICK REVISION TABLE

Technique	Description	Advantage	Disadvantage
Manual	Created by tester	Simple	Slow
Automated	Tool-generated	Fast	Needs tools
Random	Random values	Good for stress	Unpredictable
Boundary-Based	Edge values	Finds bugs	Limited scope
Data Subsetting	Real data sample	Realistic	Limited data
Data Masking	Hide sensitive data	Secure	Extra effort

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🎯 FINAL SUMMARY

• Test data is input used for testing

• Types:

  • Valid
  • Invalid
  • Boundary (very important)
  • Edge cases

• Techniques include:

  • Manual
  • Automated
  • Random
  • Data masking

• Good test data ensures:

  • Better quality
  • More bug detection

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