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gokila selvaraj
gokila selvaraj

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Manual Testing Techniques

1️⃣ Common Manual Testing Techniques:
Manual testing techniques help testers create effective test cases to find defects without using automation tools.
A. Equivalence Partitioning (EP)
Definition: Divide input data into valid and invalid groups so that testing one value from each group is enough.
Example:
Suppose a form accepts ages 18 to 60.
o Valid partition: 18–60 → test with 25
o Invalid partitions: <18 and >60 → test with 17 and 61
This reduces test cases while maintaining coverage.


B. Boundary Value Analysis (BVA)
Definition: Test values at the edges of valid and invalid input ranges since most errors occur at boundaries.
Example:
For input range 1–100:
Test with 0, 1, 2, 99, 100, and 101
→ Ensures correct handling at lower and upper limits.


C. Decision Table Testing
Definition: Test all possible combinations of inputs and conditions using a table.
Example:
A loan system grants approval only if both conditions are true:

o Salary > ₹50,000
o Experience > 5 years

Rule Salary > 50k Experience > 5 Loan Approved

1 No No No
2 Yes No No
3 No Yes No
4 Yes Yes ✅ Yes

• → This ensures you don’t miss any logical combinations.


D. State Transition Testing

Definition: Test how the system behaves when it moves between different states.
Example:
ATM System:

o State 1: Card Inserted → Enter PIN → Withdraw → Card Ejected.

You test transitions like:

o Enter wrong PIN 3 times → Card Blocked (Invalid transition)
o Enter correct PIN → Proceed (Valid transition)


E. Error Guessing

Definition: Based on the tester’s experience and intuition to find common errors.
Example:
o Entering blank username/password fields
o Typing special characters in numeric fields
o Uploading invalid file formats


2️⃣ Boundary Value Analysis (BVA)

A black-box testing technique where testers focus on values at boundaries of input domains.

Example:
An online exam system accepts marks between 0 and 100.
• Test inputs: -1, 0, 1, 99, 100, 101
• Expected results:
o -1 → Invalid (below range)
o 0 → Valid (minimum)
o 1 → Valid
o 99 → Valid
o 100 → Valid (maximum)
o 101 → Invalid (above range)
Why use it?

Because developers often make off-by-one errors, and these are caught only by testing boundary conditions.


3️⃣ Decision Table Testing

Definition:
A systematic way to test all combinations of conditions and actions in business logic using a decision matrix.

Example:
For an online discount rule:
• Condition 1: Customer is a member
• Condition 2: Purchase amount > ₹5000

Rule Member Amount > 5000 Discount (%)
1 No No 0
2 Yes No 5
3 No Yes 10
4 Yes Yes 15

→ Ensures all logical rules are verified.
When to Use:
When multiple conditions determine the outcome (e.g., banking, insurance, or e-commerce systems).


4️⃣ The Future of Manual Testing in the Age of AI
Current Trend:

AI and automation are revolutionizing testing, but manual testing is still important for human judgment, creativity, and usability validation.
Automation vs Manual Testing:
Area Automation/AI Strength Manual Testing Strength
Repetitive Regression Tests Fast and consistent Not efficient
Exploratory Testing Limited context Deep insight & creativity
UI/UX Feedback Detects layout issues Understands user emotions
Complex Business Scenarios Needs rules to learn Humans adapt easily

Example:
• AI Testing: Can detect if a button is missing.
• Manual Tester: Can say “The button placement confuses users.”

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