Why would a researcher conduct a double-blind experiment?
A double blind experiment is an experimental method used to ensure impartiality, and avoid errors arising from bias. It is very easy for a researcher, even subconsciously, to influence experimental observations, especially in behavioral science, so this method provides an extra check.
What is true about a double-blind experiment?
An experiment of this type is said to be double blind. It is called this because two parties are kept in the dark about the experiment. Both the subject and the person administering the treatment do not know whether the subject in the experimental or control group. This double layer will minimize the effects of some lurking variables.
Why are placebos used in experiments?
What is the correct definition of a placebo? Why do researchers use a placebo? Researchers use placebos during studies to help them understand what effect a new drug or some other treatment might have on a particular condition. For instance, some people in a study might be given a new drug to lower cholesterol. Others would get a placebo.
Why are drug studies done as double blind experiments?
This procedure is utilized to prevent bias in research results. Double-blind studies are particularly useful for preventing bias due to demand characteristics or the placebo effect . For example, let's imagine that researchers are investigating the effects of a new drug.
What is the purpose of single and double blind studies?
Single-blind usually means that the research participant is not told of the treatment assignment. Double-blind usually means that the research participant, investigator, study coordinator/nurse, study sponsor, and in some cases the data analyst are kept unaware of the treatment assignment.
What is the purpose of using a single blind experiment?
A type of clinical trial in which only the researcher doing the study knows which treatment or intervention the participant is receiving until the trial is over. A single-blind study makes results of the study less likely to be biased.
What is the reason for using a double blind design for an experiment?
The best and most reliable form of research is the double-blind, placebo-controlled study. The purpose of this kind of study is to eliminate the power of suggestion. The double-blind study keeps both doctors and participants in the dark as to who is receiving which treatment.
What is the purpose of a double blind or double masked study?
A type of clinical trial in which neither the participants nor the research team know which treatment a specific participant is receiving. This helps prevent bias or expectations from influencing the results of the study.
What is the advantage of a blind experiment?
If good blinding is carried out on the subjects, it can eliminate any form of biases that may arise from the subjects' expectations, influence from the researcher, researcher's bias, and other forms of biases that may occur in a research test.
What are the benefits of blinding in experimental research explain?
Blinding of one or more parties is done to prevent observer bias. This refers to the fact that most (if not all) researchers will have some expectations regarding the effectiveness of an intervention. Blinding of observers provides a strategy to minimize this form of bias.
What is the purpose of blind and double-blind experimental designs quizlet?
a. A double-blind study is one in which neither the participants nor the experimenters know who is receiving a particular treatment. This procedure is utilized to prevent bias in research results.
In which experiment would a double-blind test be most appropriate?
A great example of double-blinding is clinical studies that are conducted to test new drugs.
Is a double-blind experiment used to increase the placebo effect?
Answer and Explanation: No, double-blind experiments do not increase the placebo effect. On the contrary, the double-blind procedure is conducted to minimize, decrease, and eliminate the influence of the placebo effect.
What is blinding and what is its purpose?
Blinding refers to the concealment of group allocation from one or more individuals involved in a clinical research study, most commonly a randomized controlled trial (RCT).
Which of the following is a difference between single blind studies and double blind studies?
In a single-blind study, only the participants are blinded. In a double-blind study, both participants and experimenters are blinded. In a triple-blind study, the assignment is hidden not only from participants and experimenters, but also from the researchers analyzing the data.
What does double blind mean in a clinical trial?
A double blind trial is a trial where neither the researchers nor the patients know what they are getting. The computer gives each patient a code number. And the code numbers are then allocated to the treatment groups.
What is a single blind experiment statistics?
In a single-blind study the participants do not know what treatment groups they are in, but the researchers interacting with them do know. In a double-blind study, the participants do not know what treatment groups they are in and neither do the researchers who are interacting with them directly.
Why does a single blind procedure control for demand characteristics?
Sometimes participants in a study will try to guess what a study is about or what they think the experimenters are hoping to find. This can lead them to change their behavior, which can ultimately skew the results. A single-blind study can help prevent this or minimize the effects of such demand characteristics.
What is a single blind design in psychology?
Single Blind: A single-blind design is when the participant doesn't know if they are in the “treatment group” or the “control (e.g. placebo) group”. The treatment group in an experiment is the group that experiences the factor that the researchers hypothesize will have an effect.
What is the purpose of experimental research?
Experimental research seeks to determine a relationship between two (2) variables—the dependent variable and the independent variable. After completing an experimental research study, a correlation between a specific aspect of an entity and the variable being studied is either supported or rejected.
What is blinding in research?
Blinding means hiding who is assigned to the treatment group and who is assigned to the control group in an experiment .
What is the difference between single-blind, double-blind and triple-blind studies?
In a single-blind study , only the participants are blinded. In a double-blind study , both participants and experimenters are blinded. In a tri...
Why is blinding important in research?
Blinding is important to reduce bias (e.g., observer bias , demand characteristics ) and ensure a study’s internal validity . If participants k...
What is the benefit of a blind study?
Blind studies eliminate possible sources of human bias and influence from the participants and/or researchers. They encourage accurate reporting an...
What is an example of a blind study?
One example of a blind study is for testing new products. The participants are unaware if they are being give the new product or the existing produ...
What is a blind study in research?
In research, a blind study is when one or more groups of involved parties do not know the independent variable being tested or into which group the...
Why is a single-blind study used?
A single-blind study is used when the researcher is the expert and would be the best person to perform the experiment. It can also be used if the r...
Need for Blind Experiment
Consider an example to understand why blind experiments are important. A food company has developed a new cereal. It has a similar appearance and taste to another popular cereal, but this cereal has fewer calories, less sugar, and more nutrients.
Single-Blind Procedure
In a single-blind procedure, the researchers get a group of volunteer participants. They are told of the possible risks and potential benefits but also that they won't know which group they are placed in. The participants must all sign consent forms agreeing to the experiment.
Single-Blind Study Example
Another example of a single-blind study is trying a new hand lotion. Each participant would be assigned to either the control or the experimental group. The control group would get a known hand lotion, while the experimental group would try the new hand lotion.
Why does the experimenter not know which group received the placebo or the experimental drug?
The fact that the experimenter does not know which group received the placebo or the experimental drug means that the risk of conscious and unconscious observer bias is reduced, making the study more accurate.
Why do blind people not know if they are taking placebos?
This is done to reduce the risk of errors, since some participants might produce spurious results if they know that they are taking the placebo or medication.
What are the two models of clinical trials?
When undertaking a clinical trial, the two major models that one can use are the single blind and double blind trials . Selecting the right trial is important since it can affect the outcome of the trial or introduce errors. The ideal model should be selected based on the type of trial and other variables. For any clinical trial, there are usually two groups of people who are experimented on. Members of one group are given a placebo, and the members of another group are given the treatment that is being studied. This is so as to compare the effectiveness of the treatment to placebo.
What is the superior model of clinical research?
In a double-blind study, both the participants and the experimenters do not know which group got the placebo and which got the experimental treatment. This is considered to be the superior model of clinical research since it eliminates outcomes that are produced due to placebo effect, as well as observer bias by the experimenter.
Why do we need double blind study?
A double-blind study reduces the risk of biases in research. Biases can occur when a researcher influences the outcome of a study directly or otherwise. However, because the researcher is often also in the dark, it is difficult to influence the study.
Why do we do single blind studies?
A single-blind study is usually conducted to prevent the subject from being aware of the treatment being studied. This is in case they get influenced and that leads to bias in the outcome.
What is a Blinded Study?
A blinded study is research conducted in a way that prevents the subjects ( blind the subjects) from knowing the treatment they are given so that the researcher is guaranteed a biased free result. Information that can influence the subjects of a research is withheld from the subjects until the completion of the research.
What is the purpose of a blind study?
A blind study prevents the participants from knowing about their treatment to avoid bias in the research.
What is the name of the study in which only the subjects in the experiment are prevented from knowing the treatment they are given?
1. Single-blind study: in this type of blind study only the subjects in the experiment are prevented from knowing the treatment they are given. The single-blind study is also known as the single masked study.
What is good blinding?
If good blinding is carried out on the subjects, it can eliminate any form of biases that may arise from the subjects' expectations, influence from the researcher, researcher's bias, and other forms of biases that may occur in a research test.
Why is a double blind study not a sample?
A double-blind study cannot provide a properly represented sample group because it is small. Most double-blind study is designed to enroll at least 100 people or participants for the research however the most preferable number is 300. It is true that the effectiveness of a treatment can be proven even in small studies but more people or participants are required to determine a pattern in research so that the results can be properly analyzed and verified.
Why is single blind study important?
A single-blind study can help prevent this or minimize the effects of such demand characteristics.
What is single blind study?
In psychology, a single-blind study is a type of experiment or clinical trial in which the experimenters are aware of which subjects are receiving the treatment or independent variable, but the participants of the study are not.
What is a study in which both the experimenters and participants are unaware of who is receiving the independent variable and who?
A study in which both the experimenters and participants are unaware of who is receiving the independent variable and who is not is known as a double-blind study.
Why do researchers keep participants in the dark about what they are looking for?
The reason for keeping participants in the dark about what the researchers are looking for and what treatment they are receiving is to try to prevent participants from altering their behavior to conform to what they think the researchers expect.
Why do we do double blind studies?
Reasons to Use a Double-Blind Study 1 First, since the participants do not know which group they are in, their beliefs about the treatment are less likely to influence the outcome. 2 Second, since researchers are unaware of which subjects are receiving the real treatment, they are less likely to accidentally reveal subtle clues that might influence the outcome of the research. 1
Why do we use double blind?
The double-blind procedure helps minimize the possible effects of experimenter bias. 2 Such biases often involve the researchers unknowingly influencing the results during the administration or data collection stages of the experiment. Researchers sometimes have subjective feelings and biases that might have an influence on how the subjects respond or how the data is collected.
Why is double blinding important?
A double-blind study can be a useful research tool in psychology and other scientific areas. By keeping both the experimenters and the participants blind, bias is less likely to influence the results of the experiment.
Why is randomized double blind placebo considered the gold standard?
2 One of the reasons for this is the fact that random assignment reduces the influence of confounding variables.
What does double blind mean in psychology?
As mentioned previously, double-blind indicates that the participants and the experimenters are unaware of who is receiving the real treatment . 1 What exactly do we mean by ‘treatment'? In a psychology experiment, the treatment is the level of the independent variable that the experimenters are manipulating.
Can you double blind in a psychotherapy experiment?
Double-blind experiments are simply not possible in some scenarios. For example, in an experiment looking at which type of psychotherapy is the most effective, it would be impossible to keep participants in the dark about whether or not they actually received therapy.
Can you take a sugar pill in a double blind study?
The rest of the subjects will receive an inactive placebo. With a double-blind study, the participants and the experimenters have no idea who is receiving the real drug and who is receiving the sugar pill.
Origins of the Double-Blind Study
One of the earliest recorded examples of the double-blinded study was conducted in 1784, by Friedrich Wilhelm von Hoven, a government health official in Germany. He wanted to test whether homeopathic drugs, which were popular at the time, were a legitimate form of medicine.
Double-Blind Control
The control group plays an important role in experimental research. As previously mentioned, this group does not receive any special treatment during the course of a study. This group serves to represent how the population behaves in regular, everyday scenarios.
Randomization
Randomization plays a similarly important role in experimental research. Ultimately, researchers are trying to attribute any observed differences between the control and treatment groups to the conditions of the study. To do this, they need to be certain they can rule out other differences that might have influenced the results of the study.
The Process of Unblinding
Researchers frequently assess participants regarding the degree of their blindness. This is often done by asking participants questions about various aspects of the study that were withheld from them. If the participants exhibit no knowledge of this withheld information, then their blinding is considered perfect.
Premature Unblinding
Researchers aim to maximize blindness as much as possible. Premature blindness occurs when participants become privy to information that was withheld about the conditions of a study before it has ended.
Unblinding After the Study
Ideally, unblinding occurs after a study has ended. That way, biases that can arise from premature blinding are avoided. The unblinding of participants is often achieved by debriefing them to inform them of the nature of the study. This is particularly important if deception was used as a way of "blinding" them before the study begins.
