Ssci Ch 8 Quiz

The one-shot case study has the least explanatory power compared to the other experimental designs. This is because it only involves a single group being observed after a treatment or intervention, without any control group or pretest. Therefore, it is difficult to establish a cause-and-effect relationship or draw conclusions about the effectiveness of the treatment. In contrast, the other designs mentioned involve control groups, pretests, or more rigorous methods, allowing for stronger inferences and explanations of the observed outcomes.

The correct answer is that the experimental group receives the independent variable and the control group does not. In an experiment, the independent variable is the variable that is manipulated or changed by the researcher. The purpose of having a control group is to provide a baseline for comparison. By not receiving the independent variable, the control group allows researchers to determine the effects of the independent variable by comparing it to the experimental group. This helps to isolate and identify the specific impact of the independent variable on the dependent variable.

In a classical experimental design, it is necessary to measure the dependent variable for both the experimental and control groups. This is because the dependent variable is the variable that is expected to be influenced by the independent variable, which is manipulated in the experimental group. By measuring the dependent variable in both groups, researchers can compare the effects of the independent variable on the experimental group to the control group, allowing for the evaluation of the effectiveness of the intervention or treatment being studied.

The Solomon four-group design combines the classical experimental design with the posttest-only control group design. This means that the experiment includes both a control group and an experimental group, and the dependent variable is measured after the manipulation or treatment has occurred. This design allows researchers to compare the effects of the treatment on the experimental group with the control group, while also taking into account any potential pre-existing differences between the groups.

In experimental research, it is important for the experimental and control groups to be comparable on variables that are likely to be related to the dependent variable under study. This ensures that any differences observed between the groups can be attributed to the independent variable and not to other factors. By controlling for these variables, researchers can minimize confounding effects and increase the internal validity of the study. Therefore, the answer "variables that are likely to be related to the dependent variable under study" is correct.

The question of internal validity refers to whether the experimental stimulus really affected the dependent variable. Internal validity is concerned with establishing a cause-and-effect relationship between the independent variable (experimental stimulus) and the dependent variable. It involves controlling for confounding variables and ensuring that any observed effects can be attributed to the experimental manipulation rather than other factors. In other words, internal validity is about determining whether the experimental stimulus had a genuine impact on the outcome measure being studied.

An instrumentation effect occurs when the measurement instrument is changed from the pretest to the posttest. This means that any differences observed between the pretest and posttest scores may be due to the change in the instrument used to measure the dependent variable, rather than any actual changes in the participants or the stimulus. This can introduce bias and affect the validity of the results.

Experiments are not particularly suitable for descriptive research. Descriptive research aims to observe and describe the characteristics of a particular phenomenon or population, without manipulating variables or testing hypotheses. Experiments, on the other hand, involve manipulating variables and testing specific hypotheses to establish cause-and-effect relationships. Therefore, experiments are not appropriate for descriptive research as they do not focus on describing phenomena but rather on testing hypotheses and establishing causal relationships.

The static-group design is the correct answer because in this design, the researcher administers the experimental stimulus to the experimental group and measures the dependent variable in both the experimental and control groups. However, unlike other designs, the subjects are not randomly assigned to groups. This design is useful for comparing the effects of the experimental stimulus on the experimental group compared to the control group, but it lacks randomization, which may introduce bias into the results.

In order for Jimmy's experiment to be ethical and respectful of the subjects' autonomy, he must inform them that he will be observing their nonverbal communications. This ensures that the subjects are aware of the true nature of the experiment and can give informed consent to participate.

The major problem in this research is that the researcher failed to control for selection biases, testing, history, and maturation. This means that the improvement in math scores may not solely be attributed to the intensive program designed to improve their math skills. There could be other factors such as differences in the students' abilities, the effect of taking the test multiple times, external events or circumstances, and natural development and growth over time that could have influenced the improvement in math scores.

Professor John has to worry about demoralization as a form of internal invalidity. The control group's realization that the experimental group is receiving lavish lunches while they are stuck with plain microwaved meals may lead to feelings of frustration, dissatisfaction, and demoralization. This could potentially affect their motivation and willingness to fully participate in the experiment, thereby introducing bias and invalidating the results.

The participant's response of giving up and quitting studying after concluding that they were in the control group and would not receive any review sessions demonstrates demoralization. Demoralization refers to a decrease in motivation or morale due to a perceived lack of benefit or disadvantageous conditions in an experiment or study. In this case, the participant's belief that they would not receive any additional help or support led to a loss of motivation and ultimately quitting studying.

Statistical regression is the most likely explanation for the friend's lowered score. This phenomenon occurs when an individual's extreme score on an initial test is likely to move closer to the average score on a subsequent test. In this case, since the friend initially scored in the 99th percentile, it is expected that their score would regress towards the mean on the second test, resulting in a lower percentile rank. This is a common occurrence in testing and is not necessarily indicative of a decline in performance or ability.

The classical experimental design helps guard against the sources of internal invalidity. Internal invalidity refers to factors within the experiment that can affect the results and make them unreliable or inaccurate. The classical experimental design includes features such as random assignment, control groups, and manipulation of independent variables, which help minimize the impact of confounding variables and ensure that any observed effects are truly caused by the independent variable. By controlling for internal invalidity, the classical experimental design increases the internal validity of the study, making the results more trustworthy and reliable.