Logical Reasoning: Weaken the Argument Questions Flashcards

A university argues that its career counseling program increases graduate employment rates because 85% of students who completed the program were employed within six months. Which most weakens this argument?

Answer: Only students who were already highly motivated and employable chose to complete the program, so their success reflects their prior attributes rather than the program's effectiveness.

Self-selection bias means the program attracted already-employable students, making it impossible to attribute their success to the program.

An environmental group argues that offshore wind farms harm marine ecosystems because whale strandings increased in areas near wind farm construction sites. Which most weakens this argument?

Answer: Ship traffic near whale habitats also increased significantly during the same construction period, and ship collisions are a known cause of whale strandings.

Increased ship traffic is an alternative explanation for the strandings that coincides with but is independent of wind farm construction.

A business consultant argues that companies should adopt four-day workweeks because employees at firms with four-day weeks report higher job satisfaction. Which most weakens this argument?

Answer: Companies that adopt four-day workweeks are also disproportionately those that already have progressive cultures and generous benefits, so satisfaction may stem from the broader environment rather than the schedule.

Progressive company culture—not the four-day schedule itself—may be the true driver of higher satisfaction.

A financial analyst argues that investing in gold protects wealth during recessions because gold prices rose during the last three recessions. Which most weakens this argument?

Answer: Three recessions is too small a sample to establish a reliable pattern, and gold prices fell sharply during some other significant economic downturns.

Citing only three favorable cases while ignoring contrary evidence constitutes cherry-picking and undermines the generalization.

A sleep researcher argues that getting at least eight hours of sleep per night improves cognitive performance because laboratory studies show that sleep-deprived subjects score lower on cognitive tests. Which most weakens this argument?

Answer: Sleep needs vary among individuals, and for some people, fewer than eight hours is optimal, making the eight-hour threshold an overgeneralization.

If individual sleep needs vary, a universal eight-hour prescription may not improve performance for those whose optimal sleep is shorter.

A city planner argues that widening a congested highway will reduce commute times because more lanes will accommodate more vehicles. Which most weakens this argument?

Answer: Induced demand means that added highway capacity encourages more drivers to use the road, eventually restoring or worsening congestion.

Induced demand predicts that new capacity attracts additional drivers, offsetting the congestion relief the extra lanes were meant to provide.

A dietitian argues that a low-fat diet is the most effective for weight loss because clinical studies in the 1980s and 1990s showed participants lost weight on such diets. Which most weakens this argument?

Answer: More recent and larger controlled trials consistently show low-fat and low-carbohydrate diets produce equivalent long-term weight loss, eliminating the claimed advantage of the low-fat approach.

If newer, higher-quality evidence shows no advantage over other approaches, the older studies do not support the claim that low-fat is the most effective strategy.