What is CAST and what is it used for?

CAST is a mnemonic acronym (Checklist, Ask, Search, Test) used for exploratory testing. It is a structured approach to exploratory testing that helps organize the defect search process.

Each element of the acronym represents a stage:

• Checklist: Using a pre-prepared or spontaneously created checklist to verify obvious or typical issues (e.g., checking input fields, design compliance, etc.).
• Ask: Asking questions to developers, business analysts, other testers, or users to clarify requirements, identify implicit expectations, or understand the logic of the functionality.
• Search: Searching for information related to the tested functionality, including documentation, logs, previous defect reports, online articles, or source code.
• Test: Performing tests based on the previous steps (checklist, answers to questions, found information). Testing in this context is more informal and aimed at exploring the system's behavior under different conditions.

CAST is used for:

• Rapid defect detection under limited time or insufficient documentation.
• Exploring unfamiliar functionality.
• Supplementing scenario testing.
• Developing testing skills and "intuition" for defects among testers.