Exam 8: Measuring

A company used to give IQ tests to all job applicants. This is now illegal because IQ is not related to the performance of workers in all the company's jobs. That is, IQ as a measure of future performance on the job is:

Ex Regious State University, in its public relations materials for prospective students, proudly points out the accomplishments of its 96 alumni who have reached the zenith of their fields: millionaires, CEOs, and university presidents. They contrast this with Pricy Small U., a small private school, in the same town, with only 22 alumni who have reached similar levels of achievement in spite of the smaller school's greater cost. Why is it not fair to use these two numbers to conclude that students from Ex Regious State do better in these fields than those of Pricy Small U.?

A nephew visits his Aunt Tess for five days. Every morning he weighs himself, and the five readings are very different. When he gets home and compares the average from his aunt's scale to the reading on his scale (which he regards as his true weight), he realizes the average is almost exactly the same. As a measure of his weight on his scale, the reading on his aunt's scale is:

Professor Iconu has developed a new test of level of spiritual awareness for his course on religions of the world. Any such test must have several versions because some people take the test more than once. Unfortunately, it turns out that the same person often gets very different scores, depending on which version of the test is offered, even when taking the versions at nearly the same time. The test suffers from:

In an experiment to study the effect of vibrations on plant growth, the height of a chrysanthemum was measured three times. The reason for making the measurement three times instead of just once was probably to:

In a recent study on veterinary practices, 25 cases of negligence were discovered at 10 randomly selected large veterinary hospitals in the state, compared to 12 cases of negligence at 10 randomly selected small veterinary clinics in the state. "The data show that it is safer to take pets to small clinics because visits to small clinics result in fewer cases of negligence." What is wrong with the preceding statement?

The diameter of a metal rod was measured eight times and the results in millimeters were: 29.2, 29.2, 29.1, 29.2, 29.2, 29.2, 29.3, 29.2. The true diameter of the rod is 29.2 millimeters. The measurement process appears to be:

A music professor says that his school's new test for "creative musical analysis" can't be trusted because the test counts any discordant string of pitches as creative. The music professor is attacking the test's:

Ex Regious State University, in its public relations materials for prospective students, proudly points out the accomplishments of its 96 alumni who have reached the zenith of their fields: millionaires, CEOs, and university presidents. They contrast this with Pricy Small U., a small private school, in the same town, with only 22 alumni who have reached similar levels of achievement in spite of the smaller school's greater cost. What would be a more appropriate measure that would make the comparison fair?

An office worker sets her coffee maker to start brewing coffee at 5:30 A.M. On some mornings it starts five minutes early. On others it starts 10 minutes early. It is always early, but there is no telling when the coffee will start to be made or be finished. The timer on the coffee maker is:

One might try to measure how rich people are by looking at the car they drive. In fact, driving a fancy car has little to do with income (most luxury cars are leased). In statistical terms, measuring income by car model is:

A radio talk show invites listeners to call a telephone number to vote Yes or No on whether they support a bond issue for a new school. About 1500 people call in. Over 80 percent say No. As an estimate of community opinion, this result is:

A measurement process that does not systematically overstate or understate the true value of the quantity being measured is called:

How can one measure intelligence? One way is to measure the size of the brain. New technology makes it possible to measure the volume of a person's brain in cubic inches without injury. What is more, the measurement gives close to the same answer when one repeats it. But how big the brain is has no relation to how smart a person is. As a measure of intelligence, brain volume is:

A student's research shows that there were more car accidents in 2015 than there were in 1915. He concludes that people were better drivers in 1915 than in 2015. What would be a more appropriate or valid measure for this comparison?

Wake Forest University claims that SAT scores should not be used to predict college success (and no longer requires them for admission), because SAT scores do not adequately measure how well students will perform when they attend college. Thus, to predict college success, the SAT score measurement is claimed to be:

Over the past few years, college enrollments have increased dramatically across the United States. Over this same time period, an educational task force reports that the number of students dropping out of college has significantly increased. A college newspaper reports on these results by stating, "In an effort to meet the demand of more students, it appears that colleges and universities are not providing the same level of support for students to graduate as they were a few years ago." What is wrong with the college newspaper's interpretation of the results?

Professor Faulpelz asks a random sample of high school freshmen about their TV viewing habits. Four years later, he obtains their final high school grade-point averages and compares these with the answers about TV viewing habits. He finds that students who watch a lot of TV get lower grades than those who don't. When it comes to high school GPA, the answers to the Faulpelz questionnaire on TV viewing habits:

In one of the first attempts to discover the speed of light, Simon Newcomb in 1882 made 66 measurements of the time light takes to travel between the Washington Monument and his laboratory on the Potomac River. Why did Newcomb repeat his measurement 66 times and take the average of the 66 as his final result?

A student's research shows that there were more car accidents in 2015 than there were in 1915. He concludes that people were better drivers in 1915 than in 2015. Why is it not valid to use these two numbers to assess driving abilities in these two years?