iSQI Updated CTFL_Syll2018 Exam Questions and Answers by arwen

State transition testing is the most suitable test technique for this situation. State transition testing is a technique that uses scenarios based on state diagrams to test the behavior of a system or component that can change its state in response to events or inputs. A state diagram is a graphical representation of the states that a system or component can be in, the events or inputs that can trigger a change of state (transitions), and the actions or outputs that can occur as a result of a change of state. In this case, the vending machine for light drinks can be modeled as a state diagram with states such as “idle”, “coins inserted”, “drink selected”, “drink dispensed”, “change returned”, “sold out”, etc., and transitions triggered by events such as “button pressed”, “coins inserted”, “drink dispensed”, “change returned”, etc. State transition testing can help design test cases that cover all the possible states and transitions of the vending machine and verify its functionality and usability.

References: Certified Tester Foundation Level Syllabus, Section 4.5.1

 The level of risk is determined by multiplying the impact of an adverse event by the likelihood of that event occurring1 . The impact of an adverse event is the degree of harm or loss that would result from the event, such as financial loss, reputation damage, legal consequences, or safety hazards1 . The likelihood of an adverse event is the probability or frequency of the event happening, based on historical data, expert judgement, or statistical analysis1 . The other options are not correct formulas for calculating risk. Option A confuses the cost of preventing an adverse event with its impact. Option B confuses the cost of possible legal action with its likelihood. Option D uses two synonyms for likelihood (probability and frequency) instead of combining it with impact.

Gaining confidence about the level of the system’s quality can be a common objective of testing, because testing can provide information about how well the system meets its specified requirements and user expectations, and how many defects have been found and fixed in the system.

According to the syllabus, the absence-of-errors fallacy is a common misconception that finding and fixing defects will ensure the success of a system. This fallacy ignores the fact that there may be other factors that affect user satisfaction and system value, such as usability, functionality, performance, reliability, security, etc. The answer D is correct because it is an example of the absence-of-errors fallacy. Since testing found very few defects, the system certainly will be successful. This statement assumes that defect detection is the only criterion for system success, which is not true. The other answers are incorrect because they are not examples of the absence-of-errors fallacy, but rather facts or challenges related to testing.

References: [Certified Tester Foundation Level Syllabus], Section 1.2.1, page 11.