Data are the actual values of a variable, such as the measured heights of 30 people.
Correct Answer
True
True. A variable is the characteristic being studied, and data are the specific values recorded for it, such as each person's height.
Category: Key Terms
Question 2
In a simple random sample, every possible group of n members of the population has the same chance of being chosen.
Correct Answer
True
True. That equal chance for every group of the chosen size is what defines a simple random sample.
Category: Sampling Methods
Question 3
Larger random samples generally produce smaller sampling error than smaller random samples.
Correct Answer
True
True. Sampling error comes from studying only part of the population, and it tends to shrink as the random sample grows.
Category: Evaluating Studies
Question 4
Confounding occurs when the effects of two or more factors on a response cannot be separated.
Correct Answer
True
True. When factors are confounded, a study cannot tell which one caused the change in the response, so valid conclusions about any single factor are hard to draw.
Category: Evaluating Studies
Question 5
A survey question worded to push respondents toward a particular answer can bias results through undue influence.
Correct Answer
True
True. Undue influence occurs when the wording or manner of data collection steers people toward certain answers, which biases the results.
Category: Evaluating Studies
Question 6
Informed consent requires that participants be told the risks of a study before they agree to take part.
Correct Answer
True
True. Participants must receive a clear explanation of the risks and agree to participate, usually in writing, before the study begins.
Category: Research Ethics
Question 7
A lurking variable is an extra variable that can affect the response and cloud the conclusions of a study.
Correct Answer
True
True. A lurking variable is not the one being studied, but it can influence the response, which is why experiments use random assignment to balance such variables across groups.
Category: Experimental Design
Question 8
An institutional review board reviews planned studies involving human subjects to protect the participants' rights and safety.
Correct Answer
True
True. Research institutions set up institutional review boards to oversee studies with human subjects, checking plans in advance for risks, informed consent and fair treatment of participants.
Category: Research Ethics
Question 9
The relative frequencies of all the values in a frequency table add up to 1.
Correct Answer
True
True. Each relative frequency is a fraction of the total, so together they account for the whole data set and sum to 1 (or very close to 1 after rounding).
Category: Frequency Tables
Question 10
Stopping data collection as soon as the results look favorable is an ethical problem in research.
Correct Answer
True
True. Ending a study at a convenient moment lets the researcher choose the result, which undermines the integrity of the findings.
Category: Research Ethics
Question 11
In a cluster sample, the researcher randomly selects a few members from every cluster.
Correct Answer
False
False. In a cluster sample, the researcher randomly selects some whole clusters and includes every member of those clusters. Taking a random sample from every group describes stratified sampling.
Category: Sampling Methods
Question 12
Zip codes are quantitative data because they are written with numbers.
Correct Answer
False
False. Zip codes are labels for locations, so they are qualitative (categorical) data. Adding or averaging zip codes has no meaning.
Category: Data and Measurement
Question 13
A scale that reads 2 pounds too heavy for every person produces sampling error.
Correct Answer
False
False. A faulty measuring device produces nonsampling error. Sampling error comes from studying a sample instead of the whole population.
Category: Evaluating Studies
Question 14
On the Fahrenheit scale, 80 degrees is twice as hot as 40 degrees.
Correct Answer
False
False. Fahrenheit temperature is interval data with no true zero, so ratios such as twice as hot are not meaningful. Only differences between temperatures can be compared.
Category: Data and Measurement
Question 15
An observed association between two variables is enough to show that one variable causes the other.
Correct Answer
False
False. An association does not establish cause and effect, because a third variable may be linked to both. A well-designed experiment is needed to support a causal conclusion.
Category: Evaluating Studies
Question 16
The response variable is the variable that a researcher manipulates in an experiment.
Correct Answer
False
False. The researcher manipulates the explanatory variable. The response variable is the outcome that is measured to see how it changes.
Category: Experimental Design
Question 17
Inferential statistics only organizes and summarizes data without drawing conclusions about a population.
Correct Answer
False
False. Organizing and summarizing data is descriptive statistics. Inferential statistics uses sample data to draw conclusions about a population.
Category: Key Terms
Question 18
In a placebo-controlled experiment, the placebo is given to the treatment group rather than to the control group.
Correct Answer
False
False. The placebo goes to the control group, while the treatment group receives the active treatment, so the two groups can be compared fairly.
Category: Experimental Design
Question 19
At the ordinal level of measurement, the differences between values can be measured precisely.
Correct Answer
False
False. Ordinal data can be put in order, but the differences between values cannot be measured. Measurable differences begin at the interval level.
Category: Data and Measurement
Question 20
A study paid for by a company with an interest in the result should be rejected automatically.
Correct Answer
False
False. A self-funded study is not automatically good or bad. It should be judged on how well it was designed and carried out.
Category: Evaluating Studies