In Software Engineering (SE), questions on testing types are very frequent. Black Box, Unit, and Integration testing are core concepts. If you prepare them clearly, you can easily answer direct and concept-based questions in ECET 2026.
📘 Concept Notes
🔎 What is Software Testing?
- Software Testing = process of verifying and validating software to ensure it meets requirements.
- Objective: detect errors, defects, or gaps in the system.
1️⃣ Black Box Testing
- Also called Functional Testing.
- Focus: What the system does (not how it works internally).
- Test cases designed from requirements/specifications.
- Example: Testing a login form by entering username & password without looking at source code.
- Techniques: Equivalence Partitioning, Boundary Value Analysis.
2️⃣ Unit Testing
- Testing individual components or modules of software.
- Usually done by developers during coding.
- Tools: JUnit (Java), PyTest (Python).
- Example: Checking if a single function
add(a, b)returns correct result.
3️⃣ Integration Testing
- Testing how modules work together.
- Ensures data flow between components is correct.
- Types:
- Big Bang Integration – all modules combined at once.
- Incremental Integration – step by step integration.
- Example: Checking if “Login module” integrates correctly with “Dashboard module”.
⚙️ No direct formulas, but use case coverage formulas in Black Box Testing
- For Equivalence Partitioning:
- For Boundary Value Analysis (BVA):
(where 
= number of variables).
📐 Example – Black Box Testing
Suppose input range = 1 to 100.
- Partitions: <1, 1–100, >100 → 3 test cases.
- Boundary values = {0,1,2,99,100,101} → 6 test cases.
🔟 10 Expected MCQs – ECET 2026
Q1. Black Box testing focuses on:
A) Code structure
B) Functional behavior
C) Performance tuning
D) Compiler optimization
Q2. Unit testing is usually performed by:
A) End users
B) Test engineers
C) Developers
D) Project managers
Q3. Integration testing is used to check:
A) Internal logic of module
B) Interfaces between modules
C) System performance
D) User interface design
Q4. Black Box testing is also called:
A) Structural testing
B) Functional testing
C) White Box testing
D) Code coverage testing
Q5. If input range is 1–50, boundary values chosen are:
A) 1 and 50 only
B) 0,1,2,49,50,51
C) 10,20,30
D) None
Q6. Which of these is NOT a Black Box technique?
A) Boundary Value Analysis
B) Equivalence Partitioning
C) Decision Table Testing
D) Path Coverage
Q7. In Unit testing, the smallest testable part is:
A) System
B) Module
C) Function/Method
D) Package
Q8. Big Bang integration testing means:
A) Testing one module at a time
B) All modules integrated and tested together
C) Random testing
D) Regression testing
Q9. Formula for BVA test cases = ?
A)
B) 
C) 
D) 
Q10. Which testing comes before Integration Testing?
A) Regression
B) Unit
C) System
D) Acceptance
✅ Answer Key
| Q.No | Answer |
|---|---|
| Q1 | B |
| Q2 | C |
| Q3 | B |
| Q4 | B |
| Q5 | B |
| Q6 | D |
| Q7 | C |
| Q8 | B |
| Q9 | B |
| Q10 | B |
🧠 Explanations
- Q1 → B: Black Box = functional behavior.
- Q2 → C: Developers test units.
- Q3 → B: Integration testing checks module interfaces.
- Q4 → B: Black Box = Functional Testing.
- Q5 → B: Boundaries: just below, on, just above → {0,1,2,49,50,51}.
- Q6 → D: Path coverage = White Box technique.
- Q7 → C: Function/method is smallest unit.
- Q8 → B: Big Bang = all modules together.
- Q9 → B: BVA test cases =
. - Q10 → B: Unit testing is done before integration.
🎯 Why Practice Matters
- SE Testing questions are direct, concept-based, and formula-linked.
- By mastering Black Box, Unit, and Integration testing → you secure easy marks in ECET 2026.
- These concepts are also widely asked in software job interviews.
