Question 1

A recent study on reorientation produced dramatic results when researchers found that college students ignore obvious landmarks while reorienting in a small confined space and performing a verbal task at the same time.However, several other studies, using the same methods at different universities, have not been able to replicate this finding.Is this important?

Accepted Answer

The fact that other studies using the same methods at different universities have not been able to replicate the original finding suggests that the initial results may not be generalizable. This is important because it raises questions about the validity and reliability of the original study's findings.

Question 2

Random sampling is most closely associated with which of the following?

Accepted Answer

Random sampling is used to ensure a representative sample for a study, which is important for generalizing findings to a larger population, thus it is most closely associated with external validity. Internal validity refers to the extent to which a study can demonstrate causal relationships between variables, and random sampling alone does not guarantee this. Reliability and interrater reliability refer to the consistency and agreement of a measure or assessment, which is not directly related to sampling method.

Question 3

A goal of _____ is to generalize from a sample to a population and help to determine the probability of a given outcome.

Accepted Answer

Inferential statistics is specifically designed to make inferences about a population based on a sample of data. Its goal is to analyze patterns and relationships within the sample and use those patterns to predict how likely those patterns are to exist in a larger population. Therefore, it helps to determine the probability of a given outcome. Descriptive statistics, on the other hand, is focused on summarizing and describing characteristics of the sample only. Validity and replication, while important in research, are not specific to the goals of inferential statistics.

Question 4

The statement "There is a difference in the number of times men and women interrupt during conversations" supports the _____ hypothesis.

Accepted Answer

The statement suggests a specific expectation or prediction about the behavior of men and women, which aligns with the concept of a research hypothesis. A research hypothesis proposes a potential outcome or relationship that can be tested through study.

Question 5

_____ refers to the duplication of scientific results.

Accepted Answer

Replication refers to the process of duplicating scientific results, typically through conducting the same study multiple times or conducting similar studies that reproduce the same findings. Sampling refers to the selection of a subset of individuals or units from a larger population to participate in a study. Random assignment refers to the process of randomly assigning participants to different groups or conditions in an experiment. Generalizability refers to the extent to which the findings of a study can be applied to other populations or situations beyond the sample used in the study.

Question 6

Springfield has two hospitals.In the larger hospital, about 45 babies are born each day, and in the smaller hospital, about 15 babies are born each day.Approximately 50 percent of all babies born in the two hospitals are girls, but the exact percentage varies from day to day.Over a period of one year, which hospital will record more days during which over 60 percent of the babies born are girls?

Accepted Answer

Assuming 365 days in a year, the larger hospital will have approximately 16,425 births (45*365) and the smaller hospital will have approximately 5,475 births (15*365). If 50 percent of all babies are girls, then on average, each hospital will have approximately the same number of girls and boys born each day. However, to have over 60 percent of babies born be girls, there would need to be at least 30 girls born each day in the larger hospital and at least 10 girls born each day in the smaller hospital. It is more likely that the smaller hospital will have more days where over 60 percent of babies born are girls, since it would take fewer girls to reach that threshold.

Question 7

Garret thinks his car battery is becoming weak.He doesn't want to be stranded on the highway, so he tests his battery and it tests fine.But when Garret begins his trip on the highway, the battery dies 20 miles down the road.The test results must have been wrong! What type of error is this?

Accepted Answer

This is a Type II error, where the test falsely indicates the battery is fine when it is actually weak.

Question 8

In a study of the effects of alcohol, a researcher compares reaction time of people who had 8 drinks against those who had 6 drinks, 4 drinks, 2 drinks, or 0 drinks.How many experimental groups are there in this design?

Accepted Answer

There are 5 conditions being tested (0 drinks, 2 drinks, 4 drinks, 6 drinks, and 8 drinks), therefore there are 5 experimental groups in this design. Choice B is the correct answer.

Question 9

Dan and Rachel decided to start running in the mornings to get a little exercise.Dan asks Rachel if she thinks she will go out for a run today, and she says there is an 80 percent chance that she will.What type of probability is this?

Accepted Answer

The probability given by Rachel is a personal probability as it is based on her own thoughts, feelings, and intentions. It is not based on any past data or statistical analysis, and it may not accurately reflect the true likelihood of her going for a run.

Question 10

Geneva believes she is allergic to cats.She has always avoided them and feels ill when she notices one is around.Katarina does not believe Geneva is actually allergic to cats since Geneva seems to have no reaction to the kitten Katarina has secretly been hiding in her room in their shared apartment.Maybe Geneva is remembering the times when she did not feel well and there were cats present and is forgetting the times she has been around cats and felt fine; this phenomenon is also known as:

Accepted Answer

Confirmation bias refers to the tendency to seek out and interpret information in a way that confirms one's pre-existing beliefs or hypotheses. In this case, Geneva may be selectively remembering times when she felt ill around cats and ignoring times when she did not, thus confirming her belief that she is allergic to cats. This is an example of confirmation bias.

Question 11

Dr.Warren thinks that criminal justice students are better analytical writers than sociology students.Which statement would be his null hypothesis?

Accepted Answer

The null hypothesis is typically represented as the opposite of the researcher's hypothesis. In this case, Dr. Warren's hypothesis is that criminal justice students are better analytical writers than sociology students. Therefore, the null hypothesis would be that there is no difference in analytical writing ability between the two groups. Option C is the only choice that represents this null hypothesis.

Question 12

Some people used to believe that the intelligence of a person was related to their head size.If there is no actual association between these variables, this would be an example of a(n):

Accepted Answer

If there is no actual association between head size and intelligence, but people still believe in such an association, it is an example of an illusory correlation. An illusory correlation is a perceived relationship between two variables that does not actually exist.

Question 13

Many people have been interested in the effects of pet ownership on overall health.Surprisingly enough, the results have been somewhat inconclusive to date.A major investigation of the issue might compare pet owners to people without pets over a 5- to 10-year period.Which group is the experimental group?

Accepted Answer

The experimental group is the group being tested to see if there is a difference in outcome compared to the control group, which in this case is people without pets. Therefore, pet owners are the experimental group in this investigation. The pets themselves and pet owners with poor health are not relevant to the comparison being made.

Question 14

Dr.Kirch is a psychiatrist and finds that 70 percent of his patients qualify as having symptoms of sleep disorders, according to the results of a questionnaire.Dr.Kirch reports that 70 percent of the population must have the same condition as well.However, this study lacks _____ due to his biased sample.

Accepted Answer

The study lacks generalizability because Dr. Kirch only used a biased sample of his own patients to make a claim about the entire population. Generalizability refers to the ability to apply the findings and conclusions from a sample to a larger population. The other choices, convenience sampling, expected relative-frequency probabilities, and reliability, are not necessarily relevant to this specific issue.

Question 15

The statement "There was no significant difference between the intelligence test scores of men and women in the current study" supports the _____ hypothesis.

Accepted Answer

The statement indicates that there was no significant difference between the intelligence test scores of men and women, which would lead us to accept the null hypothesis (which states that there is no significant difference between the groups being compared).

Question 16

Many people have been interested in the effects of pet ownership on overall health.Surprisingly enough, the results have been somewhat inconclusive to date.A major investigation of the issue might compare pet owners to people without pets over a 5- to 10-year period.Which group is the control group?

Accepted Answer

The control group is the group that does not receive the treatment being tested, in this case pet ownership. Therefore, the control group in this study would be people without pets (choice B). Pet owners (choice A) would be the experimental group being compared to the control group. The pets themselves (choice C) and pet owners with poor health (choice D) are not relevant to the control group in this study.

Question 17

A weight-loss guru is offering free exercise training and diet plans for people who want to participate in her program.She finds that 85 percent of the participants who signed up lost an average of 30 pounds in just six months.She then promotes her program as the most effective plan available and promises each participant a weight loss of 20 pounds or more.Is her plan really as effective as she says?

Accepted Answer

The study is based on a volunteer sample, which may be very different from a randomly selected one. Therefore, the results cannot be generalized to the larger population. Additionally, the fact that the study only included participants who signed up for the program may introduce a bias towards individuals who are more motivated or have more disposable income to spend on weight-loss programs.

Question 18

Jack and Hugo each bought a lottery ticket.Hugo's ticket is 4, 8, 15, 16, 23, 42, and Jack's ticket is 1, 2, 3, 4, 5, 6.Who is more likely to win the lottery?

Accepted Answer

Each lottery ticket, regardless of the numbers chosen, has an equal chance of winning because each number combination is as likely to be drawn as any other.

Question 19

In a famous experiment on the unreliability of eyewitness testimony, participants first watched a video of a car wreck and were then asked either, "How fast was the car going when it hit the other car?" or "How fast was the car going when it smashed into the other car?" The hypothesis was that the word "smashed" would induce higher estimates of speed than the word "hit." What is the null hypothesis?

Accepted Answer

The null hypothesis is always that there will be no significant difference between groups or conditions. In this case, the null hypothesis would be that both groups (the "hit" and "smashed" groups) will give similar estimates of speed. This is because the null hypothesis assumes that there is no effect of the wording of the question on participants' estimates of speed.

Question 20

Dr.Spock finds results that match his previous predictions.He claims that he has proven his hypothesis.What should he have said?

Accepted Answer

The correct statement is that the findings reject the null hypothesis. In scientific research, when results match predictions, it typically means that the evidence is against the null hypothesis (which usually states there is no effect or no difference). Saying the findings "support his hypothesis" is more accurate than claiming proof, as science works on evidence and support rather than absolute proof.

Quiz 5: Sampling and Probability