Junior techniques
Test the form. Break the form. Document what breaks. At junior level you apply systematic techniques — equivalence partitioning, boundary values, decision tables — instead of relying on instinct.
1. Equivalence Partitioning (EP)
ISTQB CTFL 4.2.1 — K3 learning objective. The exam will ask you to apply EP to derive test cases from a specification.
Spec: A quantity field accepts values from 1 to 100.
How many invalid partitions are there?
Full reference with worked examples →
2. Boundary Value Analysis (BVA)
Once you have your partitions, test the edges. Most bugs hide at the boundary.
Spec: "Items must be less than 50."
Is 50 a valid or invalid input?
Use 2-value BVA (boundary + one outside) as a minimum. Use 3-value BVA (below, at, above) for high-risk fields.
ISTQB CTFL 4.2.2 — K3. Apply both 2-value and 3-value BVA. Always pair with EP — EP defines the partitions, BVA tests their edges.
Full reference with worked examples →
3. Decision Table Testing
When multiple conditions interact, build a table. List all conditions as rows, all combinations as columns, and the expected action for each combination at the bottom. Each column = one test case.
Classic use case: login form. Conditions: valid username (Y/N), valid password (Y/N). Four combinations. Each column is a test case with an expected result.
ISTQB CTFL 4.2.3 — K3. The exam will give you a specification and ask you to derive test cases using a decision table. Practice building the table before writing the test cases.
Full reference with worked examples →
4. State Transition Testing
For systems with defined states (e.g., order: Pending → Confirmed → Dispatched → Delivered), model the states and transitions, then test every valid path and every invalid transition.
At junior level: identify the states, draw the transitions, verify each transition works and invalid ones are rejected with a useful error.
ISTQB CTFL 4.2.4 — K3. Know how to achieve all-state coverage (visit every state) and all-transition coverage (exercise every valid transition).
Full reference with worked examples →
5. Form validation testing
Apply EP and BVA systematically to every field:
- Required fields — submit with every required field empty, then one empty at a time.
- Format validation — email: test "notanemail", "user@", "@domain.com". Phone: test international codes, spaces, dashes, all letters.
- Length limits — find the min and max. Test at boundary values.
- Type validation — number fields: test negative, zero, decimal, letters, very large numbers.
6. Error message quality
For every validation error, ask:
- Does an error message appear at all?
- Is it near the field that caused the error?
- Does it explain what is wrong (not just "invalid input")?
- Does it tell the user how to fix it?
- Does it clear when the user corrects the field?
- Does it appear after submit or as the user types? (Both behaviours are valid — but it should be consistent.)
7. Error guessing
After systematic techniques, add targeted attacks based on what tends to break. Common targets for junior-level testing:
- Empty fields, null values, spaces-only input
- SQL injection strings:
' OR '1'='1 - Very long strings (1000+ characters)
- Zero and negative numbers in numeric fields
- Double-submitting a form
Full reference with fault lists →
8. Use Case Testing
Testing the system from the perspective of a user performing a task. A "Use Case" describes the interaction between an Actor (User) and the System to achieve a goal (e.g., "Withdraw Cash").
How: Test the "Main Success Scenario" (Happy Path) and then test the "Extensions" (what happens if the user has no balance?).
ISTQB CTFL 4.2.5 — K2. Understand how use cases identify gaps in business logic that simple field validation might miss.
9. Checklist-Based Testing
Using a pre-defined list of points to check. This ensures consistency across different testers and different pages. Checklists can be based on standards (WCAG) or common past failures.
10. Defect Management
What happens after you find a bug? Defect management is the process of tracking the bug from New to Fixed and finally Closed. You'll learn to use tools like Jira or Azure DevOps to manage this flow.
11. AI-Augmented Testing (Modern QE)
Systematic techniques are the foundation, but AI is the force multiplier. In modern Quality Engineering, you use AI to accelerate your work:
- Test Data Generation — Use LLMs to generate complex JSON payloads or diverse input sets that would take hours to write by hand.
- Logic Analysis — Provide a requirement spec to an AI and ask it to identify potential Equivalence Partitions you might have missed.
- Bug Reporting — Use AI to help structure your bug reports, ensuring they are clear, concise, and include all necessary steps to reproduce.
The goal is Human-in-the-Loop testing: AI proposes, human validates. You remain the guardian of quality.
ISTQB CTFL mapping
| Technique | ISTQB ref | Exam level |
|---|---|---|
| Equivalence Partitioning | 4.2.1 | K3 — Apply |
| Boundary Value Analysis (2-value & 3-value) | 4.2.2 | K3 — Apply |
| Decision Table Testing | 4.2.3 | K3 — Apply |
| State Transition Testing | 4.2.4 | K3 — Apply |
| Use Case Testing | 4.2.5 | K2 — Understand |
| Error Guessing | 4.4.1 | K2 — Understand |
| Exploratory Testing | 4.4.3 | K2 — Understand |