Experimental Design 90%
One of the purposes of an experiment is to determine whether the dependent variable affects the independent variable. t/f?
false?
Compare and contrast extraneous variables with confounding variables.
Both types of variables have the potential to interfere with the relationship between the independent and dependent variable. Extraneous variables aren't included in the study but can still influence the results of the study if unaccounted for or if not controlled. Confounding variables interfere with study results due to having a connection with the independent variable that is not easy to separate or distinguish. A confounding variable can be considered a type of extraneous variable.
Describe the difference between convenience sampling and quota sampling.
Convenience sampling is based on the availability of participants or volunteers, and quota sampling is based on selecting participants from specific groups to make sure each group is properly represented for the study.
What is the difference between an independent and a dependent variable?
The difference between an independent variable and a dependent variable in an experiment is that the independent variable is the one that the researcher will change or alter in order to test the effects of the change on the dependent variable. The purpose of the experiment is to observe the relationship between changes in the independent variable and changes in the dependent variable. If the dependent variable changes as a result of the changes in the independent variable then the researcher knows that the two variable has a relationship.
A(n) __________ refers to a substance or treatment that is often used in an experiment but does not have an actual medicinal or experimental benefit. A. extraneous variable B. placebo C. confounding variable D. independent control
b
The degree to which the findings of a study may be applied to a larger population represents how ___________ a sample is. A. inaccurate B. generalizable C. convenient D. large
b
Both the experimental group and the control group are exposed to the same __________. A. type of treatment B. independent variable C. confounding variables D. experimental conditions
b?
Which is the fairest way to take a representative sample from a population? A. choosing participants who will ensure that study results will support the hypothesis B. carefully selecting specific subjects who meet one's criteria from the population C. ensuring that every subject in the population has an equal chance to be selected D. using a survey to screen out participants who may interfere with other subjects
c?
Understanding the effect of any confounding variables on the dependent variable is important to the outcome of an experiment. t/f?
true?
Explain the reason why random sampling is preferred in psychological studies.
Random sampling is preferred in psychological studies because it increases the generalizability of a study. A randomly generated sample is less influenced by any researcher bias since the researcher is not selecting participants directly. Since every member of a population has an equal chance to be selected in a random sample, it is more likely that the sample can be generalized back to the target population because the members of the sample are more likely to be representative of the population as a whole.
What is the difference between the control group and the experimental group in an experimental study?
The difference in the control and experimental groups is the application of the independent variable. The experimental group has the independent variable altered or manipulated to test the effects on the dependent variable so the researcher can observe the effects of this change. In the control group, the independent variable is not applied to them. This group serves as a group for the researchers to compare the experimental group to in order to see if any changes that occur in the experimental group is really due to the manipulation of the independent variable.
If everyone in the population has an equal chance of inclusion in a study, then one would say that the study used a ___________ sampling technique for the study. A. random B. quota C. convenience D. availability
a
Read the hypothesis below and answer the question that follows. Individuals who smoke will have a higher frequency of developing cancer later in life. Which of the following would not be a potential extraneous variable for the stated hypothesis? A. the occurrence of lung cancer in subjects B. exposure to secondhand smoke C. the amount of cigarettes smoked per day by subject D. the number of years as a smoker
a
Read the experimental design below and answer the question that follows. A researcher wants to determine the effects of sleep on memory and decides to schedule two groups of subjects for a sleep study. Both groups will be asked to memorize as many items as they can from the same prepared list of items. Then they will be allowed to go to sleep. In group A, the subjects will only be allowed to sleep for six hours. In group B, the subjects will be allowed to sleep for their usual amount of time. After each subject is finished sleeping, a quiz will be given over the list that was supposed to be memorized. What is the independent variable in the experiment? A. amount of sleep B. group B subjects C. memory D. group A subjects
a?
Which of the following is a disadvantage of conducting a laboratory experiment? A. Cause-and-effect relationships are easier to determine in laboratory experiments. B. Laboratory experiments do not generally reflect real-life circumstances. C. There is more objectivity in measuring the dependent variable in laboratory experiments. D. Replicating the study is difficult for laboratory experiments.
b
Which of the following is an example of convenience sampling? intentionally surveying a population of men about football preferences instead of women in order to focus more on the male response a dentist surveying patients about toothpaste preference taking data from a random selection of people across the country on television program preferences surveying college students from ten different universities on academic rigor over ten years
b
Which of the following statements about extraneous variables is not accurate? A. An extraneous variable can also be a confounding variable. B. An extraneous variable clarifies the relationship between the independent and dependent variables. C. An extraneous variable can alter the results of an experiment in an undesired way. D. An extraneous variable cannot be the same as an independent variable.
b
__________ variables are manipulated by the experimenters. A. Dependant B. Independent C. Control D. Targeted
b
In a __________ study, the subjects do not know to which group they are assigned, but the researchers are aware of the subjects' group assignments. A. double-blind B. placebo C. single-blind D. control
c
One advantage of experiments is that they ___________. A. can be difficult to design B. are often realistic C. allow cause and effect to be considered D. can be affected by human error
c
Quota sampling is mostly based on participant availability or volunteers. t/f?
false?
The control group in an experimental study will __________. be excluded from the results of the experiment if they contradict the hypothesis receive no treatment during the experiment be informed at the outset of the experiment that they are the control group receive the same treatment as the experimental group
receive no treatment during the experiment
A confounding variable can also be considered an extraneous variable. t/f?
true?
A well-designed experiment can be replicated by others. t/f?
true?
Convenience sampling can produce biased research results. t/?
true?
Placebos are sometimes used in research in order to demonstrate the effects of participant expectations or beliefs on the outcome of behavior. t/f?
true?
