UCMP MC

Consider this example. Which option has the strongest correlation?

Answer explanation

They are all the same set of data!  

Stretching the x or y scale affects the appearance of the data cloud.

A research team is conducting a survey to determine the favorite sports of students in a large university. They decide to distribute their survey only in the university's sports arena during a basketball game. What type of bias might be introduced into their survey?

• Observer bias

• Selection bias

• Measurement error

• Non-response bias

A company conducts a series of experiments to test the effectiveness of a new dietary supplement. After many experiments, they find one test where the supplement had a significant effect on a specific health parameter. They focus on this single result and use it to market the supplement as a miracle product. What is the primary problem with the company’s approach?

• Their experiments do not show any useful information.

• They have not conducted a comprehensive review of all experiments.

• They are not accurately representing the overall results of their experiments.

• The supplement has consistently demonstrated no health benefits in all experiments.

A cosmetic advertisement claims, “Experimental results show that our product can remove 80% of facial wrinkles and improve skin in just 10 days.” If we assume these data indeed originate from an experiment, can we trust these numbers, and why?

Answer explanation

Some keywords:

Sample Size: Was the experiment conducted with a large enough group to be statistically significant?

Control Group: Was there a control group used in the experiment for comparison?

Bias: Were there any potential biases in the study, such as participant selection or funding sources?

Replicability: Can the results be replicated in further studies?

Statistical Significance: Are the results statistically significant rather than due to chance?

Placebo Effect: Was the placebo effect accounted for in the study design?

Transparency: Are the methods and data of the study transparent and accessible?

You are flipping a fair coin, and it has landed on heads five times in a row. What do you expect the outcome of the next flip to be?

• Heads

• Tails

• The probability is the same for both outcomes