“Experience based" test design techniques, typically.

Experience-based test design techniques are techniques that use the skill, intuition, and experience of testers to derive test cases, using error guessing and exploratory testing1. Error guessing is a technique that uses common sense and previous experience to guess where defects might occur in a system1. Exploratory testing is an approach that involves simultaneous learning, test design, and test execution1. Experience-based test design techniques are typically used when there is insufficient information or time to apply other more formal techniques1. They do not use decision tables, identify the structure of the system or software, or establish traceability from test conditions back to the specifications and requirements.