Argument Evaluation

Analyze the flawed reasoning in each argument below. Match each argument (1-4) to the abstract description that most accurately identifies its logical vulnerability.

Museum Curator: Over the past decade, the percentage of bronze artifacts in our collection requiring extensive structural restoration has steadily decreased, while the percentage of marble artifacts requiring such restoration has significantly increased. Therefore, our preservation team is currently performing extensive structural restorations on a larger number of marble artifacts than bronze artifacts.

The reasoning in the museum curator's argument is most vulnerable to criticism on the grounds that the argument:

Match each flawed argument to the description that most accurately identifies the vulnerability in its reasoning.

Agricultural scientist: Over the past year, many farmers in the Oakhaven region transitioned to using a newly developed pest-control spray on their apple orchards. A recent survey shows that orchards using the new spray suffered, on average, a 15 percent higher rate of crop damage from insects compared to orchards that continued using the traditional pesticide. Therefore, the new pest-control spray must be less effective at repelling insects than the traditional pesticide.

Which of the following, if true, most seriously weakens the agricultural scientist's argument?

Marine Biologist: Over the past decade, the population of the silver-finned reef shark in the Salerian Sea has declined by nearly 40 percent. During this same period, commercial fishing operations have steadily increased their use of deep-water drift nets in the region. Since drift nets frequently entangle large marine predators, environmentalists have blamed the fishing industry. However, recent surveys show that the shark population has declined just as sharply in the northern marine sanctuary, where all commercial fishing has been strictly banned for twenty years. Therefore, the increased use of drift nets cannot be the primary cause of the shark's decline.

Which of the following, if true, most seriously weakens the marine biologist's argument?

Ecologist: A forest ecosystem is truly stable only if it contains a highly diverse network of mycorrhizal fungi. Recent soil analyses confirm that the newly protected Blackwood Reserve contains one of the most highly diverse networks of mycorrhizal fungi ever documented in the region. Therefore, we can confidently conclude that the Blackwood Reserve is a stable forest ecosystem.

Which one of the following most accurately describes a flaw in the ecologist's reasoning?

Political Sociologist: To foster genuine civic engagement, a local government must provide its citizens with transparent access to public records. When citizens lack this transparency, they inevitably become cynical about the political process and withdraw from public participation. The municipality of Oakhaven has recently overhauled its digital infrastructure, successfully guaranteeing complete public access to all municipal records. Consequently, Oakhaven is guaranteed to experience a resurgence in genuine civic engagement.

Which of the following most accurately describes a flaw in the political sociologist's reasoning?

Read the argument and evaluate the statement that follows.

City Planner: Any city that successfully revitalizes its downtown commercial district must offer extensive public parking. The municipality of Riverbend recently constructed several large public parking facilities in its downtown area. Therefore, Riverbend's downtown commercial district will undoubtedly be successfully revitalized.

Statement: The city planner's argument is vulnerable to criticism on the grounds that it treats a condition that is necessary to bring about a particular outcome as a condition that is sufficient to guarantee that outcome.

Read the following argument:

Mayor: To boost local tourism, we should allocate municipal funding to restore the historic Riverton Mill. Our neighboring town, Greendale, restored their historic train station last year, and they saw a 25 percent increase in tourist visits this summer. Therefore, restoring our mill will similarly increase Riverton's tourist visits.

Evaluate the following statement: The mayor's argument is actively weakened by the fact that Riverton's historic mill is structurally compromised and will require significantly more funding to restore than Greendale's train station did.

Retail Manager: We should shift our promotional focus from weekend afternoon events to weekday evening events. At our most recent weekday evening event, 40 percent of the attendees purchased a premium membership. By contrast, at our most recent weekend afternoon event, only 15 percent of the attendees purchased a premium membership. Clearly, the weekday evening event generated a greater total number of premium membership sales than the weekend afternoon event did.

The reasoning in the retail manager's argument is most vulnerable to criticism on the grounds that the argument:

Musicologist: The upcoming symphony relies on a highly unusual compositional approach. Each individual instrument in the orchestra has been assigned a part that consists entirely of soothing, traditional melodies. Therefore, when the orchestra performs the piece, the overall acoustic effect of the symphony will undoubtedly be soothing and traditional.

The reasoning in the musicologist's argument is most vulnerable to criticism on the grounds that the argument:

Archaeologists recently unearthed a set of highly standardized basalt weights in the ruins of Kaelen, an inland settlement dating to roughly 1800 BCE. These weights are virtually identical in mass and geometric shape to the standard merchant weights used during the same era in the distant coastal metropolis of Tylos. Historians have long maintained that the treacherous mountain range separating the two regions prevented any direct contact before 1200 BCE. Nonetheless, based on the discovery of these matched weights, Dr. Aris concludes that Kaelen and Tylos must have established a direct trade network with one another by 1800 BCE.

Which of the following, if true, most seriously weakens Dr. Aris's argument?

Archaeologist: Excavations at the ancient settlement of Veridia have uncovered hundreds of specialized obsidian tools. Obsidian does not occur naturally anywhere near Veridia. The nearest known geological source of obsidian from that era is the Khalen mountain range, located over 500 miles away. Interestingly, other settlements surrounding Veridia from the same time period show absolutely no evidence of obsidian use. Clearly, the inhabitants of Veridia must have established a direct, exclusive trade route with the people living in the Khalen mountains.

Consider the following statement: Nomadic hunter-gatherer groups frequently traveled between the Khalen mountains and the Veridian region, bartering raw materials for food with isolated settlements along their migration paths.

The provided statement, if true, actively weakens the archaeologist's argument.

HR Director: Every engineer assigned to the new Alpha Project team is a recognized expert who has individually produced highly efficient, bug-free code on past solo assignments. Because the team is composed exclusively of such exceptional programmers, the team as a whole will undoubtedly produce highly efficient, bug-free software.

The reasoning in the HR Director's argument is flawed in that it:

Match each flawed argument to the statement that most accurately describes the logical error committed in its reasoning.

Match each argument on the left with the piece of counter-evidence on the right that most effectively weakens its conclusion.

Sociologist: A recent study of corporate professionals reveals a strong positive correlation between the number of hours an individual spends reading fiction per month and their demonstrated empathy in collaborative settings. Therefore, the habit of reading fiction directly enhances a person's capacity for empathy.

Evaluate the following statement as true or false:

The introduction of new data showing that professionals who spend comparable hours reading exclusively non-fiction literature do not exhibit these elevated levels of empathy actively weakens the sociologist's argument.

Marine biologist: Over the last decade, the population of the blue-crested penguin on Solara Island has dropped by 30 percent. During this same ten-year period, the number of commercial fishing vessels operating in the island's surrounding waters has doubled. The nets used by these vessels are known to frequently entangle and drown deep-diving seabirds. Therefore, the increase in commercial fishing must be the primary cause of the decline in the blue-crested penguin population.

Which one of the following, if true, most seriously weakens the marine biologist's argument?

Book Reviewer: Professor Lin's new book argues that modern agricultural practices are severely depleting soil nutrients and threatening long-term food security. However, Professor Lin recently accepted a lucrative position at an institute funded exclusively by organic farming advocacy groups. Since she has a clear financial incentive to promote alternatives to modern agriculture, her conclusions regarding soil depletion are completely invalid.

Statement: The book reviewer's argument is vulnerable to criticism because it illicitly infers a causal connection between two factors based solely on their observed association.

Marine biologists studying the decline of coral reefs around the Tolman Islands have blamed the recent rise in local water temperatures. However, a new study shows that reefs surrounding the neighboring Banton Islands, which have experienced the exact same rise in water temperatures, are thriving and show no signs of decline. Therefore, it is clear that rising water temperatures are not the primary cause of the coral decline around the Tolman Islands.

Statement: The assertion that the coral species dominating the Banton Islands reefs possess a unique genetic adaptation making them highly resilient to temperature fluctuations—an adaptation absent in the coral species found around the Tolman Islands—actively weakens the argument above.