Evaluating Scientific Explanations Answers

Read the claim about caffeine.Caffeine improves mental alertness and motor coordination. A university research study was conducted to examine how moderate doses of caffeine affect fine motor skills. Ten teen girls, ages 14 to 18, were given 200 mg of caffeine per day for 30 days. Thirty minutes after taking the caffeine, each subject took a timed fine motor skills test in which they fitted 20 small beads onto pegs. The graph compares each subject’s average results on the same test done 30 minutes before and after taking the caffeine.

Which source is reliable?

What is it called when scientists in the same or similar field of study judge the quality of a fellow scientist’s scientific claim?

Read the article by Michael Fumento, writer for the New York Post editorial blog, who does not support global warming.Back in 2005 I and others reviewed the entire hurricane record, which goes back over a century, and found no increase of any kind. Yes, we sometimes get bad storms—but no frequently now than in the past. The advocates simply ignored that evidence.Fact is, the earth was cooling and warming long before greenhouse gases could have been a factor. The [global warming supporters] have been proved wrong time and time again.

Which factor is found in a scientific claim?

Sharon reads two different articles about avocados. The first article, in a weight-loss magazine, claims that avocados are unhealthy because they are high in fat. The second article, in an annual publication from a doctors’ group, claims that the fat in avocados is a type that is good for the heart.To assess these claims, which question might Sharon ask?

Read the passage about the fluoridation of drinking water.Since the early 1960s, fluoride has been added to many sources of drinking water to prevent cavities in teeth. This is called fluoridation. There are some who say that this is unnecessary and increases the risk of cancer.In 1993, the Subcommittee on Health Effects of Ingested Fluoride of the National Research Council, part of the National Academy of Sciences, conducted an extensive study about the link between fluoridated drinking water and increased cancer risk. The study included data from more than 50 human disease studies and six animal studies. The Subcommittee concluded that none of the data showed a link between fluoridated drinking water and cancer. A 1999 report by the CDC supported these findings. The CDC report concluded that studies so far have produced "no credible evidence” of a link between fluoridated drinking water and an increased risk for cancer.

Cookware companies have been using a chemical called C-8, which helps to create a nonstick coating to pans. However, the Environmental Protection Agency (EPA) recently claimed that the use of C-8 in the manufacturing of nonstick cookware should be discontinued because studies show it causes cancer.

Which is one way that scientists ensure that data is reliable?

Read the excerpts about climate change.Article 1, found on the website of the Natural Resources Defense Council, a certified charitable organization, supports global warming.Global warming doesn't create hurricanes, but it does make them stronger and more dangerous. Because the ocean is getting warmer, tropical storms can pick up more energy and become more powerful. So global warming could turn, say, a category 3 storm into a much more dangerous category 4 storm. In fact, scientists have found that the destructive potential of hurricanes has greatly increased along with ocean temperature over the past 35 years.Article 2 was written by Michael Fumento, writer for the New York Post editorial blog, who does not support global warming.Back in 2005 I and others reviewed the entire hurricane record, which goes back over a century, and found no increase of any kind. Yes, we sometimes get bad storms—but no frequently now than in the past. The advocates simply ignored that evidence.Fact is, the earth was cooling and warming long before greenhouse gases could have been a factor. The [global warming supporters] have been proved wrong time and time again.

If data are from a trusted source and the results are validated by multiple tests, which describes the evidence supporting a scientific claim?

Which is an unreliable source?

In a recent survey of students who graduated from a large public high school, nine out of ten students reported that they passed biology with a grade of seventy-five percent or higher. What further data could be produced to be sure that this information is accurate?

If peers accept a scientific paper’s claim, what is the next step in the process?

Read the claim.Breakfast is an important meal. It jump starts the body’s process of using calories to break down food. Appetite can decrease with age, but going too long without eating causes metabolism to slow down. Current research shows that incorporating legumes such as lentils and chickpeas into meals boosts metabolism for twenty-four hours.

Which source is most likely an authority on the subject?