CTFL_Syll_4.0 Exam Dumps : ISTQB Certified Tester Foundation Level (CTFL) v4.0

Confirmation testingis performed after a defect is fixed to confirm it no longer exists (A).Regression testingensures new defects have not been introduced in unchanged parts of the system. Regression testing is broader than confirmation testing and covers unmodified areas affected by the changes. Options B, C, and D misrepresent the relationship and scope of these tests.

The three-point test estimation technique is a method of estimating the test effort based on three initial estimates: the most optimistic, the most likely, and the most pessimistic. The technique uses a weighted average of these three estimates to calculate the final estimate, which is also known as the expected value. The formula for the expected value is:

Expected value = (most optimistic + 4 * most likely + most pessimistic) / 6

Using the given values, the expected value is:

Expected value = (6 + 4 * 30 + 54) / 6 Expected value = 30 person hours

However, the expected value is not the only factor to consider when estimating the test effort. The technique also calculates the standard deviation, which is a measure of the variability or uncertainty of the estimates. The formula for the standard deviation is:

Standard deviation = (most pessimistic - most optimistic) / 6

Using the given values, the standard deviation is:

Standard deviation = (54 - 6) / 6 Standard deviation = 8 person hours

The standard deviation can be used to determine a range of possible values for the test effort, based on a certain level of confidence. For example, using a 68% confidence level, the range is:

Expected value ± standard deviation

Using the calculated values, the range is:

30 ± 8 person hours

Therefore, the final estimate is between 22 person hours and 38 person hours, which is option A.

Boundary Value Analysis (BVA)focuses on test cases at the edges of partitions because defects often occur at boundaries. The temperature ranges are:

≤7 (Too cold → W)

[8-21] (Standstill → X)

[22-29] (Ideal → Y)

≥30 (Too hot → Z)

Atwo-point BVAmeans testing both thelower and upper boundary valuesof each partition.

The correct selection{7,8,21,22,29,30}includes:

7 → Boundary of Too Cold (W)

8 → Lower boundary of Standstill (X)

21 → Upper boundary of Standstill (X)

22 → Lower boundary of Ideal (Y)

29 → Upper boundary of Ideal (Y)

30 → Lower boundary of Too Hot (Z)

This ensures maximum boundary coverage.