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In this illustration, different sample sizes influence the results of the experiment. However, only male rats should have been studied, because they more accurately represent the population of humans who use cells phones.

False; both sexes should always be presented whenever possible.

The news headline "Shampoo Causes Alopecia" described a study designed to determine the impact of shampoo type on alopecia. A total of 70 men (40 for the shampoo group and 30 for the no-shampoo group) and 200 women (130 for the shampoo group and 70 for the no-shampoo group) were recruited. How many participants were placed in the experimental group?

170

Which statement is false regarding epidemiological studies?

Epidemiological studies are considered unethical because they often harm participants.

Which statement is a pitfall for making decisions from a single epidemiological study?

Complexity of a disease makes it unlikely that every variable can be controlled for, small sample sizes can influence the accuracy of results, and the specific population in the study may not be representative of the general population.

Based on a thorough literature review, a researcher has found studies supporting correlations between drug use and neurological diseases, weight gain, and brain cancer. Based on these correlations, what can he conclude regarding drug use?

Drug use may cause neurological diseases, weight gain, and brain cancer.

A team of journalists has decided to take a survey asking a group of 100 people whether herbal supplements help to alleviate symptoms of depression. The survey asks participants about their own personal experiences with herbal supplements. Would the results of the journalists' survey be considered "reliable" and prove that herbal supplements either alleviate or have no effect on symptoms of depression?

No. The survey carried out by these journalists relies on anecdotal evidence, and as such would not be considered "reliable" when evaluating hypotheses regarding herbal supplements and depression.

An epidemiologist looks at a compilation of studies done at a medical center in which they have cataloged the lifestyle and habits of thousands of women. When she looks at the women in this group who have contracted breast cancer versus those who are healthy, she finds that women who have breast cancer drink more milk than those who do not have cancer. Does this mean that drinking milk causes breast cancer?

No; just because a correlation exists does not mean that milk is the cause of cancer.

Melanoma rates are higher in areas of the United States with a high number of sunny days each year. Melanoma rates have been observed to decrease in some countries in response to public health campaigns that promote regular use of sunscreen. Other types of skin cancer, which are similar to melanoma, are linked to UV exposure. Based on this information, what is the MOST comprehensive hypothesis that can be generated?

People who use sunscreen have lower rates of skin cancer in general.

Which statement about small sample sizes is true?

Small sample size experiments can be inaccurate due to chance.

A person's friend is reading a newspaper article, which notes that, in rats, a positive significant relationship exists between sugar consumption and obesity. The more sugar a rat consumes, the higher its overall body mass. This person's friend asks what it means that the results of this experiment were statistically significant. How should this person answer the question?

The fact that rats that consume more sugar have higher body masses is not due to chance.

The nightly news anchor reports that a scientific paper from a high-impact journal claims that a drug used for the treatment of diabetes increases the likelihood of death from COVID-19. What would someone ask the news anchor about the rigor of the study if only one question was allowed to be asked?

Was the study conducted on human subjects, and was is a randomized clinical trial?

Which experiment would BEST test the hypothesis that exposure to cell phone radiation increases the incidence of brain cancer?

a large sample size experiment consisting of two groups of mice: one group treated with cell phone radiation and an untreated group

In a study designed to test whether cell phone radiation increases the incidence of brain cancer, which of these is the experimental group?

animals treated with cell phone radiation

Researchers are hoping to determine the efficacy of a new drug that (supposedly) reduces cholesterol in patients. To this end, they carry out a randomized clinical trial, where one group of subjects receives the cholesterol drug and the other group receives a placebo. Researchers then periodically measure the cholesterol levels in individuals from both of these groups. In this scenario, _____ would be considered the dependent variable.

cholesterol levels in subjects

After evaluating 1,000 individuals who smoke, a researcher discovered that smokers are more likely to develop tumors affecting the nervous system (i.e., brain, spinal cord, and nerves throughout the body). This researcher has just demonstrated a(n) _____ between smoking and the development of certain cancers.

correlation

Which of these may be used as a placebo in an experiment designed to test whether caffeinated coffee improves memory?

decaffeinated coffee

A study was conducted to investigate if the use of SPF30 sunscreen lotion is a more effective skin cancer prevention measure than SPF15 sunscreen lotion. The study involved comparing a group of roofers who had developed skin cancer to a group of roofers without skin cancer and assessing their use of sunscreen lotions. This is an example of a(n):

epidemiological case-control study.

A group of scientists wants to determine whether a relationship exists between alcohol consumption and certain types of cancer. To this end, scientists provide study participants with a questionnaire asking them how many alcoholic drinks they have per week and what diseases they have (if any). These scientists provide subjects with a similar questionnaire annually (for a decade). These scientists are performing a(n):

epidemiological study.

A study showed a correlation between low dietary fat intake and reduced breast cancer risk in postmenopausal women. A 22-year-old woman can conclude that she will reduce her breast cancer risk by eating a low-fat diet.

false

Statistically significant results are more likely to be obtained from experiments that:

have a large sample size in both groups.

This figure shows data from an experiment that examined the contribution of cell phone use to the development of brain cancer. What is the dependent variable?

incidence of brain cancer

A research group has determined that a positive correlation exists between autoimmune diseases and wine consumption; wine drinkers are more likely to develop autoimmune diseases (such as rheumatoid arthritis) later in life. Based on these data, what might cause autoimmune diseases?

individuals drinking wine, other behaviors exhibited by wine drinkers, the environments in which wine drinkers live, or unknown factors

A researcher is setting up a randomized clinical trial to evaluate the effect of acetaminophen on liver function, and designates a control group of subjects and an experimental group of subjects. What could interfere with the results or completion of this study?

members of the experimental group failing to take acetaminophen according to the experimental regimen

A researcher designed a randomized clinical trial to evaluate the effect of antibiotics on treating influenza symptoms. What would be the BEST control group?

no treatment

Hypotheses that have been confirmed by numerous repeated experiments eventually become:

scientific theories.

Which phrase is NOT a factor influencing the misrepresentation of research data in the media? Please choose the correct answer from the following choices, and then select the submit answer button. Answer choices

scientists intentionally obscuring research data to make it difficult for non-scientists to understand their results

A magazine has published three different graphs depicting the relationship between diet and heart disease. All three graphs demonstrate a positive correlation between the amount of fat and salt in an individual's diet, and the likelihood that that individual will develop heart disease. However, each graph represents a different study with a different sample size. The first graph depicts a study with a sample size of 10, the second graph depicts a sample size of 100, and the third graph depicts a sample size of 1,000. Which of these three studies would likely demonstrate the MOST statistically significant data?

the study evaluating the relationship between diet and heart disease in a sample size of 1,000