Argument from Evidence Flashcards

A student claims, 'My plant grew taller because I played music for it.' Which piece of evidence would be needed to properly support this claim?

Answer: Data showing the plant that heard music grew taller than an identical plant that did not hear music, with all other conditions being the same.

A scientific claim must be supported by evidence from a controlled experiment. Comparing the growth of a plant with music to an identical 'control' plant without music (while keeping water, light, and soil the same) provides the necessary evidence to isolate the effect of the music.

A company advertises a new sports drink by saying, 'Famous athletes drink our product, so it must be the best for hydration.' What is the primary flaw in this argument?

Answer: The argument uses an endorsement instead of scientific evidence about hydration.

This is a logical fallacy known as 'appeal to authority' or 'endorsement.' The fact that a famous person uses a product is not scientific evidence of its effectiveness. A valid argument would present data from studies comparing hydration levels, electrolyte content, etc.

Two students are debating why a puddle of water disappeared from the sidewalk on a sunny day. Student 1 says: 'The sun's heat caused the water to evaporate.' Student 2 says: 'The concrete absorbed all the water.' What evidence would best support Student 1's argument?

Answer: Placing a clear bowl over a similar puddle and observing water droplets forming on the inside of the bowl.

Placing a bowl over the puddle traps the water vapor as it evaporates. When the vapor cools against the bowl's surface, it condenses back into liquid droplets. This directly demonstrates that the water turned into a gas and rose into the air, which is the process of evaporation.

A scientist presents data from an experiment showing that a new medication lowered cholesterol in 75% of participants. Which of the following is a valid claim based on this evidence?

Answer: The medication was effective for a majority of the participants in the study.

The evidence states the medication worked for 75% of participants. This directly supports the claim that it was effective for a majority (more than half) of the group studied. The other claims are too strong ('guaranteed cure'), not supported by the data ('no side effects'), or require a comparison that isn't provided.

A student argues that heavier objects fall faster than lighter objects. They support this by dropping a bowling ball and a feather, observing that the bowling ball hits the ground first. Why is this a weak argument?

Answer: The argument ignores the significant effect of air resistance on the feather.

The argument is weak because it fails to account for a critical variable: air resistance. Air resistance has a much greater effect on the light, wide feather than on the dense, compact bowling ball. In a vacuum (with no air), they would fall at the same rate due to gravity.

Which statement is an example of scientific evidence, not an opinion?

Answer: Global average temperatures have increased by 1.1°C since the late 19th century.

This statement is a specific, measurable, and verifiable piece of data that comes from scientific observation and record-keeping. The other statements express a belief ('serious problem'), a judgment ('best solution'), or a call to action ('should work harder'), which are opinions or interpretations.

A group of students investigates which type of soil retains the most water. Their data shows that the least amount of water drained from the funnel containing clay. What is the strongest argument they can make based on this evidence?

Answer: In our experiment, clay retained more water than sand or loam.

This statement is a direct conclusion from the evidence collected. It accurately describes the result of their specific investigation without making overly broad claims (like it's 'best for all plants') or stating opinions (like sand is 'bad'). A strong argument sticks to the data.