Question 1

During any given year, approximately 19% of the American population experiences a diagnosable mental illness. This is a statement of the ______ of mental illness.

Accepted Answer

Prevalence refers to the proportion of individuals in a population who have a particular condition or disease at a specific point in time. In this case, the statement is indicating the proportion of the American population who experience a mental illness during any given year, making prevalence the appropriate term to use.

Question 2

The ______ is a statistical hypothesis that is tested to determine if there is a difference between the experimental and control groups.

Accepted Answer

The null hypothesis is the hypothesis that is tested in statistical analysis to determine if there is a significant difference between the experimental and control groups. It typically posits that there is no effect or no difference.

Question 3

Prevalence is BEST defined as

Accepted Answer

Prevalence refers to the proportion of individuals who have a particular disorder at a particular time period, regardless of when the disorder first appeared. Option A is the correct definition of prevalence, while options B and C refer to lifetime prevalence and incidence, respectively. Option D is not a valid definition of prevalence.

Question 4

The confound hypothesis is BEST defined as a

Accepted Answer

The confound hypothesis is a concept that suggests that the observed effect could be due to a factor other than the independent variable. It is not a statistical hypothesis or test, nor is it a formal statement of the relationship between the dependent and independent variables. Therefore, the best answer is D.

Question 5

Addie is wondering whether the memory scores of her participants may have reflected not the difference in retention interval between the experimental and control conditions in her experiment but rather a difference in participants' ages between the two conditions. Addie's question concerns the ______ hypothesis.

Accepted Answer

Addie's question is related to the possibility of a confounding variable, which is a variable that is not controlled for in the experiment and could potentially explain the results. In this case, age could be a confounding variable if it is related to both the retention interval and the memory scores. Therefore, the best choice is A, confound. The other options (B, research; C, null; D, inferential) do not directly relate to the issue at hand.

Question 6

The director of a community health organization reads that about 1,300 new cases of HIV infection are expected in her city in the coming year. This statement illustrates an epidemiological statistic called ______.

Accepted Answer

Incidence is the measure of the number of new cases of a disease or infection in a population over a specified period, which is exactly what the director of the community health organization is referring to in this statement.

Question 7

______ statistics are computed to assess the relationship between the characteristics of the sample and those of the population.

Accepted Answer

Inferential statistics are used to make inferences about the population based on the characteristics of the sample. These statistics help us to determine how likely it is that the sample represents the population accurately. Operational and experimental statistics are more focused on defining and measuring variables, while null statistics are used to test hypotheses.

Question 8

The number of new cases of a disorder that develop during a certain period of time is called ______.

Accepted Answer

Incidence refers to the number of new cases of a disorder that develop during a certain period of time. Risk refers to the probability of developing a disorder, significance refers to the importance or impact of a finding, and prevalence refers to the total number of cases of a disorder present in a population at a given time.

Question 9

In a longitudinal design,

Accepted Answer

In a longitudinal design, a group of participants is followed for a long time. This allows researchers to study changes over time within the same group of people, which can provide valuable insights into development and behavior. A single individual can also be studied in great detail, but this is not characteristic of a longitudinal design. Participants of different age groups can be observed at the same time in a cross-sectional design, but this is not longitudinal. Observing participants without interfering describes a naturalistic observation, which is not necessarily longitudinal.

Question 10

A ______ is also known as a small-N design.

Accepted Answer

A single-subject design is also known as a small-N design, which involves studying the behavior of one individual or a small group of individuals repeatedly over time, often using experimental manipulations. Choice B, match subjects design, involves selecting participants who are matched on specific characteristics and then randomly assigning them to different groups. Choice C, longitudinal study, involves studying a group of individuals over an extended period of time. Choice D, linkage analysis, is a genetic method used to identify genes that contribute to a specific trait or disorder.

Question 11

At a DUI checkpoint, some cars are stopped at random, but many others are not stopped. Using the terminology of psychological research, the cars that are stopped may be considered a ______ of all of the cars that pass by the checkpoint.

Accepted Answer

The cars that are stopped at the DUI checkpoint represent a sample of all the cars that pass by the checkpoint. A sample is a subset of the larger population that is selected to participate in a study or to be observed in some way. In this case, the cars that are stopped are chosen at random to be checked for signs of driving under the influence, while the cars that are not stopped are not observed. Therefore, the stopped cars represent a sample of the larger population of all the cars that pass by the checkpoint.

Question 12

______ twins arise from the situation in which two different eggs are fertilized by two different spermatozoa.

Accepted Answer

Dizygotic (fraternal) twins arise when two separate eggs are fertilized by two different sperm, leading to the formation of two separate zygotes that develop separately. The resulting twins are no more genetically alike than siblings born at separate times. Heterozygotic and homozygotic refer to the genetic makeup of an individual, while monozygotic (identical) twins arise from one fertilized egg that splits into two separate embryos.

Question 13

The study of the distribution and determinants of the frequency of a disorder in humans is known as ______.

Accepted Answer

Epidemiology is the study of the distribution and determinants of frequency of a disorder in humans. Pathology is the study of structural and functional changes in tissues and organs associated with disease. Symptomology is the study of the symptoms and signs of diseases. Etiology is the study of the causes of diseases.

Question 14

Which of the following statements BEST expresses the relationship between a sample and a population?

Accepted Answer

A population includes a sample because a sample is a subset of a population, selected to represent the population in a study or analysis.

Question 15

Of the three types of hypotheses described in the text, the ______ statistical rather than conceptual.

Accepted Answer

The null hypothesis is a statistical hypothesis that assumes there is no significant difference between the groups being compared. It is a hypothesis about the population parameter (mean, proportion, standard deviation, etc.) and is tested using statistical methods. Therefore, the null hypothesis is a statistical hypothesis rather than a conceptual hypothesis.

Question 16

As part of her master's thesis work, Amy is conducting a survey of dating attitudes and behaviors among young adults. She first distributes questionnaires to 200 randomly selected students enrolled in introductory psychology courses at her university. The 200 students constitute Amy's ______. The people to whom she assumes her results will generalize are termed the ______.

Accepted Answer

The 200 students are a sample, as Amy has only surveyed a subset of the larger population of young adults. The people to whom she assumes her results will generalize are the population, which in this case are young adults in general, not just the 200 students she surveyed.

Question 17

In ______ sampling, each member of the population is equally likely to be included in the sample.

Accepted Answer

In random sampling, each member of the population has an equal chance of being selected. This ensures that the sample is unbiased and representative of the population. Choice A, linkage sampling, is not a valid sampling method. Choice C, matched sampling, involves selecting individuals who have similar characteristics, which may introduce bias. Choice D, blind sampling, refers to a procedure where the researcher collecting data is unaware of the identity of the participants, but it doesn't necessarily ensure equal probability of selection for all members of the population.

Question 18

Reba and Reni are twins. They developed from a single fertilized egg dividing shortly after conception. Reba and Reni are ______ twins, more colloquially called ______ twins.

Accepted Answer

Reba and Reni are identical twins as they developed from a single fertilized egg dividing shortly after conception, making them monozygotic. Fraternal twins are dizygotic, meaning they come from two different eggs fertilized by two different sperm.

Question 19

With respect to single-subject designs, treatment is to baseline as ______ is to ______.

Accepted Answer

In single-subject designs, the treatment phase is compared to the baseline phase. This is similar to an experimental condition being compared to a control condition in traditional group designs. Therefore, the best choice is D, where treatment is to baseline as experimental condition is to control condition. Choices A, B, and C are not accurate comparisons for this scenario.

Question 20

A randomly selected sample increases the likelihood that experimental results will generalize to the population. In other words, a random sample increases ______ validity.

Accepted Answer

External validity refers to the extent to which the findings of a study can be generalized beyond the specific sample used in the study. By selecting a random sample, researchers increase the likelihood that the sample is representative of the population, which enhances external validity. Conceptual validity refers to the adequacy of the operational definitions of the variables under study, internal validity refers to the extent to which the study design and procedures control for alternative explanations for the observed results, and longitudinal validity refers to the ability to draw accurate conclusions over time. While random sampling may impact these types of validity to some extent, it primarily affects external validity.

Quiz 3: Research Methods