Error Guessing:

The tester has to guess what fault might occur and to design the tests to represent them.

Equivalence Class Partitioning:

The input domain data is divided into different equivalence data classes; take few valid values with 2 invalid values. This is used to reduce the total number of test cases to a finite set of testable test cases.

Boundary value analysis:

Boundary value analysis testing technique is used to identify errors at boundaries rather than finding those exist in center of input domain. Boundary value analysis is a next part of Equivalence.