Question 1

In an experimental strategy,a set of procedures or manipulations is performed in order to create different values of the dependent variable for the research participants.

Accepted Answer

In an experimental strategy, the independent variable is manipulated to observe its effect on the dependent variable.

Question 2

It is possible that 2 variables can appear to be related to each other but there is no causal relationship.

Accepted Answer

Just because two variables may be correlated or appear to have a relationship, it does not necessarily mean that one variable causes the other. Other factors or variables may be influencing the relationship or there may be a coincidence between the two variables. Causality can only be determined through carefully designed experiments and statistical analysis.

Question 3

Twenty alcoholics are given a test to measure anxiety before and after a one-month detox program.The appropriate design for testing the significance of the difference between the two group means is a
A)between-subjects design.
B)within-subjects design.

Accepted Answer

A within-subjects design is ideal for this situation as each participant serves as their own control, with anxiety levels measured before and after the detox program. This design provides more statistical power to detect potential differences between the two group means. A between-subjects design would require recruiting two groups of participants, one for the pre-test and one for the post-test, which could introduce confounding variables like individual differences in alcohol history and previous treatment experience.

Question 4

The robustness of statistical test is determined by sample size only.

Accepted Answer

Although sample size is a factor that can affect the robustness of a statistical test, it is not the only factor. Other factors include the level of significance chosen, the distribution of the data, and the presence of outliers.

Question 5

When studying the relationship between two variables,the investigator is essentially interested in determining how the different values of one variable are associated with the values of another variable.

Accepted Answer

This statement is true. The goal of studying the relationship between two variables is to understand how changes in one variable affect the other variable.

Question 6

The ability to make a causal inference between two variables is a function of the statistical technique used to analyze the data that are yielded by the research design.

Accepted Answer

Causal inference depends on the research design, such as randomized controlled trials, rather than just the statistical technique used.

Question 7

Statisticians may determine the effects of violating assumptions by
A)using mathematical logic
B)conducting a Monte Carlo study
C)both of these
D)none of these

Accepted Answer

To determine the effects of violating assumptions, statisticians can use both mathematical logic and Monte Carlo studies. Mathematical logic can be used to deduce the consequences of violating assumptions, while Monte Carlo studies can simulate data under various scenarios to see how different assumptions affect the results. Therefore, both options are valid and useful for determining the effects of violating assumptions in statistical analyses.

Question 8

In a(n)_____design,an individual in one condition is paired with a different individual in another condition who has similar characteristics.
A)independent groups design
B)correlated groups design
C)matched-subjects design
D)repeated measures design

Accepted Answer

In a matched-subjects design, individuals in different conditions are paired based on their similar characteristics. This helps to control for individual differences and increases the internal validity of the study. The other options listed all refer to different types of experimental designs that do not involve pairing individuals based on their characteristics.

Question 9

The advantage of including a control group when utilizing an experimental strategy is that it provides a baseline for evaluating the effects of the experimental manipulation.

Accepted Answer

Including a control group allows for comparison to the experimental group, providing a baseline for evaluating the effects of the experimental manipulation. This increases the internal validity of the study.

Question 10

In contrast to an experimental strategy,an observational strategy or a non-experimental strategy involves the process of actively creating values on an independent variable for the research participants.

Accepted Answer

In contrast to an experimental strategy, an observational strategy or a non-experimental strategy does not involve the process of actively creating values on an independent variable for the research participants. Instead, participants are observed in their natural setting without manipulation.

Question 11

Scores on a math aptitude exam for 30 males were compared to those of 30 females.The appropriate design for testing the significance of the difference between the two group means is a
A)between-subjects design.
B)within-subjects design.

Accepted Answer

A between-subjects design is appropriate for testing the significance of the difference between two independent groups, which in this case are males and females. In a between-subjects design, different participants are assigned to each group, and their scores are compared to determine if there is a significant difference between the groups. On the other hand, a within-subjects design involves the same participants being tested in two different conditions, and the scores are compared to determine if there is a significant difference. Therefore, a between-subjects design would be the best choice for this scenario.

Question 12

An advantage of matching over holding a variable constant is that
A)it may restrict the generalizability of the results.
B)within a group the confounding variable does not vary.
C)for each individual in one group there is a comparable individual in each of the other groups who has the same value on the confounding variable.
D)all individuals within a group have the same value on the confounding variable.

Accepted Answer

Matching ensures that for each individual in one group, there is a comparable individual in each of the other groups who has the same value on the confounding variable. This helps to eliminate the potential impact of the confounding variable on the outcome variable. Option A is incorrect because matching does not necessarily restrict the generalizability of the results. Option B is incorrect because it is not necessary for the confounding variable to be constant within a group. Option D is incorrect because matching does not necessarily ensure that all individuals within a group have the same value on the confounding variable.

Question 13

An observational study manipulates an independent variable.

Accepted Answer

Observational studies do not involve direct manipulation of independent variables. Instead, the researcher observes and measures variables as they naturally occur without any intervention or manipulation. Therefore, the correct statement would be "an experimental study manipulates an independent variable."

Question 14

A major goal of research design is to create alternative explanations.

Accepted Answer

The major goal of research design is to eliminate alternative explanations and establish a clear cause-and-effect relationship.

Question 15

An advantage of using a within-subjects design instead of a between-subjects design is
A)it is more economical in terms of participants
B)more control over confounding variables.
C)it reduces the chances of carryover effects.
D)a and b
E)all of these

Accepted Answer

A within-subjects design is more economical because it requires fewer participants, and it provides more control over confounding variables since the same participants are used in all conditions, reducing variability due to individual differences. However, it does not reduce carryover effects; in fact, it may increase them.

Question 16

_____ statistics focus on differences between distributions of scores and can be used to analyze quantitative variables that are measured on an _____level.
A)Parametric;interval
B)Parametric;ordinal
C)Nonparametric;interval
D)Nonparametric;ordinal

Accepted Answer

The answer of _____ statistics focus on differences between distributions...

Question 17

Parametric statistical test assumes that there is homogeneity of variance in both groups.

Accepted Answer

Parametric statistical tests, such as t-tests and ANOVA, assume that there is homogeneity of variance in both groups being compared. This assumption is necessary to ensure that the results of the test are accurate and reliable. If the assumption of homogeneity of variance is violated, alternative non-parametric tests may need to be used instead.

Question 18

Experimental strategies automatically control for confounding variables.

Accepted Answer

Experimental strategies do not automatically control for confounding variables; researchers must design the experiment carefully to account for them.

Question 19

A cross-sectional design is the same as a longitudinal but the latter takes longer.

Accepted Answer

A cross-sectional design involves collecting data at a single point in time or over a short period, while a longitudinal design involves collecting data over an extended period, often months or years. Therefore, a longitudinal design takes longer.

Question 20

One disadvantage of using a within-subjects design is carry-over effects from condition to the next.

Accepted Answer

Carry-over effects occur when the effects of one condition linger into the next condition, potentially affecting the results. This is a common concern and limitation of within-subjects designs.

Quiz 9: Principles of Research Design and Statistical Preliminaries for Analyzing Bivariate Relationships

In an experimental strategy,a set of procedures or manipulations is performed in order to create different values of the dependent variable for the research participants.

It is possible that 2 variables can appear to be related to each other but there is no causal relationship.

Twenty alcoholics are given a test to measure anxiety before and after a one-month detox program.The appropriate design for testing the significance of the difference between the two group means is a

The robustness of statistical test is determined by sample size only.

When studying the relationship between two variables,the investigator is essentially interested in determining how the different values of one variable are associated with the values of another variable.

The ability to make a causal inference between two variables is a function of the statistical technique used to analyze the data that are yielded by the research design.

Statisticians may determine the effects of violating assumptions by

In a(n) _____design,an individual in one condition is paired with a different individual in another condition who has similar characteristics.

The advantage of including a control group when utilizing an experimental strategy is that it provides a baseline for evaluating the effects of the experimental manipulation.

In contrast to an experimental strategy,an observational strategy or a non-experimental strategy involves the process of actively creating values on an independent variable for the research participants.

Scores on a math aptitude exam for 30 males were compared to those of 30 females.The appropriate design for testing the significance of the difference between the two group means is a

An advantage of matching over holding a variable constant is that