Myers Approach:

• He compares the role of the tester as the role of the doctor.

• Testers as doctors need to have knowledge about possible defects(illness) in order to develop the defect hypothesis.

• They use these hypothesis to:

• Designing of test cases.

• Designing of test procedures

• Assemble test sets

• Select the testing levels for appropriate testing.

• Example:unit and integration testing.

• Evaluating the results of the test.

"A successful testing approach will prove the hypothesis is true,that is,the hypothesized defect was present,the software can be repaired."

Defect Classes:

• Based on the phase in which the defects are categorized as 4 types:

1. Requirements/ specifications defects.

2. Design defects.

3. Code defects.

4. Testing defects.

1. Requirements/Specifications Defects:

• Since many requirements and specification documents  are written using a natural language representation.

• Here,the defects may arise because the requirements and specifications are written in the local languages ,some people may not understand the document clearly.

• These may arise ambiguous,contradictory,unclear ,imprecise and redundant requirements.