A multinational corporation recently introduced a voluntary wellness program for its employees. After one year, an independent consulting firm evaluated the program's effectiveness by surveying employees who had actively participated in the program for at least six months. Over 85 percent of the surveyed employees reported significant improvements in their physical health and a reduction in workplace stress. Based on these results, the consulting firm concluded that the wellness program is highly effective at improving employee well-being and should be implemented across all branches of the corporation.
Which one of the following is the most serious flaw in the consulting firm's argument?
- It draws a broad conclusion about the efficacy of a program based on a sample of individuals whose continued participation makes them unrepresentative of the target population.Cevap
- BIt inappropriately infers that the program will be effective for all employees from evidence that it was effective for most of the employees in the survey.
- CIt takes for granted that the reported improvements in physical health were actually caused by the wellness program rather than by some other coincidental factor.
- DIt assumes that what is true of a specific, localized subset of employees must also be true of the corporation's workforce as a whole.
- EIt draws a conclusion about absolute numbers of employees benefiting from the program based solely on evidence regarding percentages.
Cevap
The option stating that it draws a broad conclusion based on a sample of individuals whose continued participation makes them unrepresentative of the target population.
The correct answer accurately identifies that the survey is based on an unrepresentative sample. By only surveying employees who voluntarily participated for at least six months, the consulting firm systematically excluded anyone who might have dropped out early because they found the program ineffective, unhelpful, or overly stressful. Therefore, the sample is heavily skewed toward those who experienced positive results.
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Anahtar Kavram
Sampling Flaw (Survivorship and Selection Bias)