When A Confound Is Discovered In An Experiment

What is a confound in an experimental study quizlet?

What is a “confound” in an experimental study? an extra variable that could explain result differences between groups.

When confounds are present in an experiment?

If other variables differ between control and experimental groups then the other variables are said to be confounds (i.e. variables that might influence the dependent variable and thereby negate the ability to make a cause-effect conclusion).

What is a confound in a psychology experiment?

n. in an experiment an independent variable that is conceptually distinct but empirically inseparable from one or more other independent variables. Confounding makes it impossible to differentiate that variable’s effects in isolation from its effects in conjunction with other variables.

What is a confound in psychology example?

What Are Confounds? Confounding variables are factors other than the independent variable that may cause a result. In your caffeine study for example it is possible that the students who received caffeine also had more sleep than the control group.

What is it meant by confounding?

Confounding means the distortion of the association between the independent and dependent variables because a third variable is independently associated with both. A causal relationship between two variables is often described as the way in which the independent variable affects the dependent variable.

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What is a confound quizlet?

Confounding: basic definition. A mixing of effects between the exposure the outcome and a third extraneous variable known as a confounder. Confounding variable. A confounding variable is independently associated with both the risk factor (exposure) and the disease (outcome).

How do you identify confounding?

Identifying Confounding

A simple direct way to determine whether a given risk factor caused confounding is to compare the estimated measure of association before and after adjusting for confounding. In other words compute the measure of association both before and after adjusting for a potential confounding factor.

How does confounding affect the results of an experiment?

A confounding variable is an “extra” variable that you didn’t account for. They can ruin an experiment and give you useless results. They can suggest there is correlation when in fact there isn’t. They can even introduce bias.

What does confounding mean in epidemiology?


Confounding is one type of systematic error that can occur in epidemiologic studies. … Confounding is the distortion of the association between an exposure and health outcome by an extraneous third variable called a confounder.

What is a confound in an experimental study?

A confounding variable also called a confounder or confounding factor is a third variable in a study examining a potential cause-and-effect relationship. A confounding variable is related to both the supposed cause and the supposed effect of the study.

What is confounding by indication?

Confounding by indication is a term used when a variable is a risk factor for a disease among nonexposed persons and is associated with the exposure of interest in the population from which the cases derive without being an intermediate step in the causal pathway between the exposure and the disease.

What are some examples of confounding variables?

Examples of Confounding Variable:
  • A mother’s education. Suppose a study is done to reveal whether bottle-feeding is related to an increase of diarrhea in infants. …
  • Weather. Another example is the correlation between murder rate and the sale of ice-cream. …
  • Slanted wood.

What is a confounding variable in psychology quizlet?

Confounding variable. an extraneous variable whose presence affects the variables being studied so that the results you get do not reflect the actual relationship between the variables under investigation.

Is a confounding variable a response variable?

A confounding variable is a variable that: – affects the response variable and also – is related to the explanatory variable. Example: Admit (yes/no) is response variable and GPA is explanatory variable. Possible confounding variable is general ambition.

What does confounding mean in research?

What is confounding? Confounding is often referred to as a “mixing of effects1 2 wherein the effects of the exposure under study on a given outcome are mixed in with the effects of an additional factor (or set of factors) resulting in a distortion of the true relationship.

What is positive confounding?

A situation in which the effect or association between an exposure and outcome is distorted by the presence of another variable. Positive confounding (when the observed association is biased away from the null) and negative confounding (when the observed association is biased toward the null) both occur.

What confounding variables mean?

A confounding variable (confounder) is a factor other than the one being studied that is associated both with the disease (dependent variable) and with the factor being studied (independent variable). A confounding variable may distort or mask the effects of another variable on the disease in question.

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What is a confound variable quizlet?

A confounding variable is an explanatory variable that was considered in a study whose effect cannot be distinguished from a second explanatory variable in the study.

What is a confounding effect quizlet?

Confounding. A distortion of the exposure-disease association due to the influence of a third factor. A confounder may fully or partially account for the observed effect of the study exposure or mask or hide an underlying true association.

What is confounding and why is it sometimes a problem in observational studies?

Confounding is the situation in which the difference in the risk of the outcome (or lack thereof) between exposed and unexposed can be explained entirely or partly by imbalance of other causes of the outcome in the contrasted groups.

How do you rule out a confounding variable?

One of the method for controlling the confounding variables is to run a multiple logistic regression. You can apply binary logistics regression if the outcome (Dependent ) variable is binary (Yes/No). In logistics regression model under the covariates include the independent and confounding variables.

Are covariates and confounders the same?

Confounders are variables that are related to both the intervention and the outcome but are not on the causal pathway. … Covariates are variables that explain a part of the variability in the outcome.

Which of the following is a property of a confounding variable?

In order for a variable to be a potential confounder it needs to have the following three properties: (1) the variable must have an association with the disease that is it should be a risk factor for the disease (2) it must be associated with the exposure that is it must be unequally distributed between the …

What happens when we ignore confounding?

Ignoring confounding when assessing the associ- ation between an exposure and an outcome variable can lead to an over- estimate or underestimate of the true association between exposure and outcome and can even change the direction of the observed effect.

How is confounding controlled in epidemiology?

Strategies to reduce confounding are:
  1. randomization (aim is random distribution of confounders between study groups)
  2. restriction (restrict entry to study of individuals with confounding factors – risks bias in itself)
  3. matching (of individuals or groups aim for equal distribution of confounders)

How does confounding variable affect dependent and independent variable?

A confounding variable is closely related to both the independent and dependent variables in a study. An independent variable represents the supposed cause while the dependent variable is the supposed effect. A confounding variable is a third variable that influences both the independent and dependent variables.

What is meant by confounding in factorial experiments?

Confounding: A confounding design is one where some treatment effects (main or interactions) are estimated by the same linear combination of the experimental observations as some blocking effects. In this case the treatment effect and the blocking effect are said to be confounded.

What are confounding variables in a study?

Confounding variables are the stowaways in a research study that can result in misleading findings about the relationship between the independent variable (IV) the input in the study and the dependent variable (DV) the results of the study.

What is the role of a confounding variable in a quantitative research?

A confounding variable in simple terms refers to a variable that is not accounted for in an experiment. It acts as an external influence that can swiftly change the effect of both dependent and independent research variables often producing results that differ extremely from what is the case.

How does the confounding variable affect the validity of the study?

How do confounding variables affect internal validity? The less chance there is for “confounding” in a study the higher the internal validity and the more confident we can be in the findings. Confounding refers to a situation in which other factors come into play that confuses the outcome of a study.

What is confounding by indication example?

What is Confounding by Indication? Confounding by indication is likely to happen when a particular medicine is linked to the outcome of interest in a study. For example let’s say you’re observational study is looking into the effects of a new drug A on outcomes for patients with cardiovascular disease (CVD).

How do you deal with confounding by indications?

Careful study design can reduce the risk of confounding by indication. For example including a range of different indications for the same exposures enables the relationship between the exposure and the outcome in relation to each of the individual indications to be analysed separately.

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What is residual confounding in observational studies?

Residual confounding is the distortion that remains after controlling for confounding in the design and/or analysis of a study. … There were additional confounding factors that were not considered or there was no attempt to adjust for them because data on these factors was not collected.

Which of the following describes what a confound is in research?

In research that investigates a potential cause-and-effect relationship a confounding variable is an unmeasured third variable that influences both the supposed cause and the supposed effect.

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