During a stress test, the performance tester observes that as the load increases, the response time remains stable until a certain point, then suddenly increases dramatically. The error rate also spikes at the same point. What is the most likely interpretation?

The test data is invalid because response time should increase gradually.

The system has reached its saturation point or a bottleneck has been triggered.

The system is performing well because it maintained stable response times for most of the test.

The error rate spike is unrelated to the response time increase.

When selecting performance metrics for a project, which factor is most important to consider?

The metrics that align with the project's business and technical goals

The metrics that are easiest to collect, regardless of relevance

The metrics that show the best performance results

The metrics that are most commonly used in the industry

A performance test team is preparing to test a new online payment system. The business has set a target: 99% of transactions must complete within 2 seconds. The test environment is a scaled-down version of production, and the team has limited time. The test lead must decide which metrics to collect to best validate the target and identify potential bottlenecks. Which approach is most effective?

Collect the 99th percentile response time, throughput, and resource utilization for all tiers.

Collect average response time and error rate only.

Collect only the 99th percentile response time for the payment transaction.

Collect network latency and bandwidth usage only.

A retail company is launching a new e-commerce platform. The business stakeholders have defined a target: during peak holiday traffic, 95% of product page requests must complete within 2 seconds. The performance test team is planning the metrics to collect. Which metric set best aligns with the stated business goal?

Maximum response time observed, total requests served, and CPU usage of database servers

Median response time for all pages, number of active sessions, and network latency

95th percentile response time for product pages, throughput, and resource utilization of web servers

Average response time for product pages, peak concurrent users, and error rate

A load test for a web application shows that the 95th percentile response time is 2.5 seconds, which is within the 3-second target. However, the 99th percentile is 7 seconds. What is the most appropriate conclusion?

The test is invalid because the 95th and 99th percentiles are too different.

The 99th percentile is an outlier and should be ignored.

The system meets the target for the majority of users, but a small percentage experience very poor performance.

The system is fully compliant because the 95th percentile is within target.

Certified Tester Performance Testing

Domain 2Objective 1

Why Performance Metrics Are Needed CT-PT Practice Questions (Page 1)

Part of the Performance Measurement Fundamentals domain, which makes up ~28% of our current practice bank. ISTQB does not publish an official question count, but from its 90-minute exam (~35–60 total, ~10–17 in this domain), expect 2–3 from this objective — we provide 21 practice questions to prepare you well beyond it. (estimate)

21questions here

5free pages

4concepts

Questions 1–5

1application · medium
During a stress test, the performance tester observes that as the load increases, the response time remains stable until a certain point, then suddenly increases dramatically. The error rate also spikes at the same point. What is the most likely interpretation?
Select an answer first
2foundation · easy
When selecting performance metrics for a project, which factor is most important to consider?
Select an answer first
3expert · hard
A performance test team is preparing to test a new online payment system. The business has set a target: 99% of transactions must complete within 2 seconds. The test environment is a scaled-down version of production, and the team has limited time. The test lead must decide which metrics to collect to best validate the target and identify potential bottlenecks. Which approach is most effective?
Select an answer first
4application · medium
A retail company is launching a new e-commerce platform. The business stakeholders have defined a target: during peak holiday traffic, 95% of product page requests must complete within 2 seconds. The performance test team is planning the metrics to collect. Which metric set best aligns with the stated business goal?
Select an answer first
5application · medium
A load test for a web application shows that the 95th percentile response time is 2.5 seconds, which is within the 3-second target. However, the 99th percentile is 7 seconds. What is the most appropriate conclusion?
Select an answer first

Finished these 5 questions?

Review the revealed explanations, or continue through the curriculum.

Next 5 questions →Back to CT-PT

Free Basic Practice is a study aid with revealable answers — not a scored exam. Examers.io is independent and not affiliated with or endorsed by ISTQB. “CT-PT” is a trademark of its owner, used for identification only.

Why Performance Metrics Are Needed CT-PT Practice Questions (Page 1)

Questions 1–5

During a stress test, the performance tester observes that as the load increases, the response time remains stable until a certain point, then suddenly increases dramatically. The error rate also spikes at the same point. What is the most likely interpretation?

When selecting performance metrics for a project, which factor is most important to consider?

A load test for a web application shows that the 95th percentile response time is 2.5 seconds, which is within the 3-second target. However, the 99th percentile is 7 seconds. What is the most appropriate conclusion?

Keep studying — Performance Measurement Fundamentals