Question

which experiment would most likely contain experimental bias?

a lab performs a test by giving bacterial colonies the same amount of different antibiotics and growing them under the same conditions.

a student tests the attraction of bees to flowers by placing four different flowers in the same location and counting how many bees visit each.

a chemistry class performs an experiment in which each reaction has the same amount of starting material and begins at the same temperature.

a company that makes pain relief medication tests the effectiveness of their own medicine compared to that of three other brands.

Explanation:

Define experimental bias

Experimental bias occurs when the design, conduct, or analysis of an experiment systematically favors a certain outcome. A common source of bias is a conflict of interest, where the researchers or sponsors have a financial or personal stake in the results.

Analyze the given scenarios

• Scenario 1: A lab testing different antibiotics under identical conditions is a standard, controlled scientific test.
• Scenario 2: A student testing bee attraction by placing different flowers in the same location is a controlled observation.
• Scenario 3: A chemistry class running reactions with identical starting materials and temperatures is a standard controlled experiment.
• Scenario 4: A pharmaceutical company testing its own product against competitors has a strong financial incentive to show that its product is superior. This conflict of interest introduces a high risk of Experimental Design bias.

Identify the most biased experiment

The fourth scenario is the most likely to contain experimental bias due to the commercial interest of the company testing its own product.

Answer:

• (A) A lab performs a test by giving bacterial colonies the same amount of different antibiotics and growing them under the same conditions.
• (B) A student tests the attraction of bees to flowers by placing four different flowers in the same location and counting how many bees visit each.
• (C) A chemistry class performs an experiment in which each reaction has the same amount of starting material and begins at the same temperature.
• (D) A company that makes pain relief medication tests the effectiveness of their own medicine compared to that of three other brands. (Correct answer)