Question 1

The major threat to the internal validity of research on articulation problems in young children is
A) regression.
B) instrumentation.
C) mortality.
D) maturation.
E) selection.

Accepted Answer

Maturation refers to natural developmental changes that occur over time and can affect the outcome of a study. In research on articulation problems in young children, maturation could lead to improvements in speech abilities due to normal development, which would affect the results of the study. Other threats to internal validity such as regression, instrumentation, mortality, and selection can also impact the results, but maturation is the most relevant in this context.

Question 2

The internal validity threat that randomization eliminates in an experimental study is
A) selection bias.
B) subject effects.
C) instrumentation.
D) history.

Accepted Answer

Randomization helps to ensure that the experimental and control groups are similar at the start of the study, reducing the risk of selection bias. Subject effects, instrumentation, and history are other threats to internal validity that may still exist even with randomization.

Question 3

Consider the following: "To what group of subjects can the research results based on this particular sample be generalized?" This question is concerned with
A) selection-maturation interaction.
B) reactive effect.
C) internal validity.
D) experimenter effect.
E) external validity.

Accepted Answer

The question is concerned with generalizability of research results, which is a matter of external validity, or the extent to which the findings of the study can be generalized to other populations or settings.

Question 4

Exhibit 10-2: In its simplest form, an experiment has three characteristics.Choose the characteristic that corresponds with each example.
-Refer to Exhibit 10-2.A posttest of the groups' intrinsic and extrinsic motivation is given.
A) The effect of the independent variable is measured through observation of the dependent variable.
B) Extraneous variables are held constant.
C) An independent variable is manipulated.

Accepted Answer

The posttest of the groups' intrinsic and extrinsic motivation serves as a measure of the effect of the independent variable, which is observed through changes in the dependent variable (in this case, motivation levels).

Question 5

Hypothesis testing is most characteristic of
A) survey research.
B) experimental research.
C) qualitative research.
D) historical research.
E) the case study.

Accepted Answer

Hypothesis testing is closely associated with experimental research, as it involves manipulating variables and comparing groups to determine whether there is a significant difference, which is a fundamental feature of experimental research.

Question 6

Exhibit 10-2: In its simplest form, an experiment has three characteristics.Choose the characteristic that corresponds with each example.
-Refer to Exhibit 10-2.One group had been rewarded with candy for turning in homework, while the other had verbal praise.
A) The effect of the independent variable is measured through observation of the dependent variable.
B) Extraneous variables are held constant.
C) An independent variable is manipulated.

Accepted Answer

In this example, the independent variable is the type of reward (candy vs verbal praise) and it is being manipulated by the researcher to see how it affects the students' homework turn-in behavior.

Question 7

When a pretest and posttest are used on all subjects in the experimental and control groups
A) the pretest may influence posttest results.
B) the experimenter knows whether it is reasonable to assume that both groups began at a similar point.
C) there may be interaction between pretest and treatment effects.
D) a and b
E) a, b, and c

Accepted Answer

When a pretest and posttest are used on all subjects in both the experimental and control groups, it allows for the assessment of whether the groups started at a similar point (B), but it also introduces the possibility that the pretest itself may influence the outcomes measured in the posttest (A), and there may be interactions between the pretest and the treatment effects (C).

Question 8

The major benefit of random assignment is it
A) reduces the plausibility of alternative explanations for the observed effects.
B) makes it possible to observe the effects of an independent variable on another variable.
C) ensures that the sample chosen for a study is similar to the population from which the sample was drawn.
D) equates the groups before the experimental treatment begins.
E) a and d

Accepted Answer

Random assignment both reduces the plausibility of alternative explanations for the observed effects and also equates the groups before the experimental treatment begins. Therefore, the best choice is E, which includes both options. Option A alone is not as complete because it does not address the equating of groups, and option D alone is not as complete because it does not address the reduction of alternative explanations for observed effects. Options B and C are incorrect as they do not describe the main benefit of random assignment.

Question 9

Which question expresses concern for the internal validity of a design?
A) Is the selected setting representative?
B) To what extent can the research findings be generalized?
C) Was the change in the dependent variable really due to the treatment?
D) What characteristics of the setting allow the findings to be generalized?

Accepted Answer

The question about whether the change in the dependent variable was really due to the treatment measures the internal validity of the design. This is because internal validity refers to the extent to which a study accurately reflects the effect of the independent variable on the dependent variable, without any outside factors or confounding variables influencing the results. Evaluating whether the treatment actually caused the change in the dependent variable is essential to ensuring the internal validity of a study.

Question 10

Exhibit 10-2: In its simplest form, an experiment has three characteristics.Choose the characteristic that corresponds with each example.
-Refer to Exhibit 10-2.Two classes were randomly selected and randomly assigned to be the experimental and control groups.
A) The effect of the independent variable is measured through observation of the dependent variable.
B) Extraneous variables are held constant.
C) An independent variable is manipulated.

Accepted Answer

The answer of Exhibit 10-2: In its simplest form, an...

Question 11

Counterbalancing is a technique that controls for
A) lack of random assignment.
B) failure to use a double blind technique.
C) experimenter effect.
D) order and carryover effects.
E) diffusion.

Accepted Answer

Counterbalancing is a technique used to control for order and carryover effects in experimental designs where participants undergo multiple conditions or manipulations. It involves systematically varying the order in which conditions are presented to different participants or within the same participant, so that the effects of each condition are balanced out across the different possible orders. Counterbalancing helps to ensure that any observed effects are not simply due to the order in which conditions were presented or the lingering effects of a previous condition. Therefore, the best choice here is D.

Question 12

The most effective way to limit the effects of extraneous variables in an experiment is to use
A) randomization.
B) matched groups.
C) homogeneous selection.
D) subjects as their own control.

Accepted Answer

Randomization helps to evenly distribute extraneous variables among the treatment groups, reducing their impact on the results. This is considered the most effective method for controlling extraneous variables. Matched groups and homogeneous selection can also help, but they are not as effective as randomization. Using subjects as their own control may be useful in certain situations, but it does not directly address extraneous variables.

Question 13

Selection bias is a threat to internal validity arising from failure to use
A) a control group.
B) counterbalancing across conditions.
C) reliable measuring instruments.
D) random assignment.

Accepted Answer

Random assignment ensures that participants are assigned to conditions in a way that is not influenced by any pre-existing differences between them. Failure to use random assignment can lead to selection bias, as certain types of people may end up in one condition more so than the other, making it difficult to determine if any observed differences are due to the treatment or due to pre-existing differences between groups. The other choices listed (control group, counterbalancing, reliable measuring instruments) are all important for experimental design and internal validity, but do not specifically address the threat of selection bias.

Question 14

A lack of original equivalency between two preexisting groups can be partly compensated for by using a pretest, posttest, and a/an
A) analysis of covariance.
B) analysis of variance.
C) factorial design.
D) randomization procedure.

Accepted Answer

Analysis of covariance (ANCOVA) can help adjust for differences in preexisting groups by using the pretest scores as a covariate. This helps to increase the statistical power of the study and improve the accuracy of the results. ANCOVA can be used in conjunction with a pretest-posttest design to control for potential confounding variables and improve the internal validity of the study.

Question 15

If a researcher makes a generalization from a study about apes to a human population, what type of validity problem might he/she have?
A) Internal
B) External

Accepted Answer

The researcher would have an external validity problem because they are trying to generalize the findings from a study about apes to humans, which may not be applicable due to differences between the species. This is a question of external validity, which refers to whether the findings can be generalized beyond the specific sample or study population. Internal validity, on the other hand, refers to whether the methods used in the study were sound and whether the measured effects can be attributed to the interventions or factors of interest.

Question 16

The experimenter effect as an internal validity threat is concerned most directly with
A) matching.
B) novelty.
C) expectations.
D) compensation.
E) selection interaction.

Accepted Answer

The experimenter effect refers to the unintended influence of the experimenter's expectations and behaviors on the participants' behavior or the results of the study. It is a threat to internal validity because it can lead to confounding variables other than the independent variable affecting the results. Therefore, the best choice is C, expectations.

Question 17

The factor most crucial in determining the effectiveness of the matching procedure for developing equivalent groups is whether
A) the matching variable is significantly related to the study's dependent variable.
B) the matching variables were assigned to both groups.
C) the sample is random and representative of the larger population.
D) the study is causal-comparative or experimental.

Accepted Answer

The factor most crucial in determining the effectiveness of the matching procedure for developing equivalent groups is whether the matching variable is significantly related to the study's dependent variable. This ensures that the groups are similar in the variable that is most important for the study.

Question 18

If the John Henry effect were exerting an influence in an experiment, one would expect
A) poor performance in the control group.
B) better performance in the control group.
C) poor performance in the treatment group.
D) better performance in the treatment group.

Accepted Answer

The John Henry effect occurs when the control group improves its performance because they are aware they are being compared to a treatment group, leading to better performance in the control group.

Question 19

The control of experimenter effect in a research study can be accomplished by
A) randomization.
B) matching.
C) double blinding
D) single blinding.
E) counterbalancing.

Accepted Answer

Double blinding controls experimenter effects by ensuring that neither the participants nor the experimenters know who is receiving a particular treatment, thus reducing bias.

Question 20

Events or influences other than the experimental treatment itself may occur between a pretest and a posttest that may affect the dependent variable.This threat is called
A) mortality.
B) history.
C) regression.
D) diffusion.
E) Hawthorne effect.

Accepted Answer

The threat described is called history, as it refers to external events or influences that may occur between the pretest and posttest, such as social or cultural changes, that could affect the dependent variable. Mortality refers to participants dropping out of the study, regression refers to extreme scores regressing to the mean, diffusion refers to treatment effects spreading to the control group, and the Hawthorne effect refers to participants altering their behavior due to awareness of being studied.

Quiz 10: Experimental Research

The major threat to the internal validity of research on articulation problems in young children is

The internal validity threat that randomization eliminates in an experimental study is

Consider the following: "To what group of subjects can the research results based on this particular sample be generalized?" This question is concerned with

Exhibit 10-2: In its simplest form, an experiment has three characteristics.Choose the characteristic that corresponds with each example. -Refer to Exhibit 10-2.A posttest of the groups' intrinsic and extrinsic motivation is given.

Hypothesis testing is most characteristic of

Exhibit 10-2: In its simplest form, an experiment has three characteristics.Choose the characteristic that corresponds with each example. -Refer to Exhibit 10-2.One group had been rewarded with candy for turning in homework, while the other had verbal praise.

When a pretest and posttest are used on all subjects in the experimental and control groups

The major benefit of random assignment is it

Which question expresses concern for the internal validity of a design?

Exhibit 10-2: In its simplest form, an experiment has three characteristics.Choose the characteristic that corresponds with each example. -Refer to Exhibit 10-2.Two classes were randomly selected and randomly assigned to be the experimental and control groups.

Counterbalancing is a technique that controls for

The most effective way to limit the effects of extraneous variables in an experiment is to use

Selection bias is a threat to internal validity arising from failure to use

A lack of original equivalency between two preexisting groups can be partly compensated for by using a pretest, posttest, and a/an

If a researcher makes a generalization from a study about apes to a human population, what type of validity problem might he/she have?

The experimenter effect as an internal validity threat is concerned most directly with

The factor most crucial in determining the effectiveness of the matching procedure for developing equivalent groups is whether

If the John Henry effect were exerting an influence in an experiment, one would expect

The control of experimenter effect in a research study can be accomplished by

Events or influences other than the experimental treatment itself may occur between a pretest and a posttest that may affect the dependent variable.This threat is called