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Old 03-24-2012
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Stats Selection versus Design Bias!

How are selection bias and design bias different?
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Old 03-25-2012
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Selection bias compares apples to oranges.

Study design might have flaws in it. Like if you have biases in it.
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Old 03-25-2012
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Selection bias would be for example, when a researcher decides to ask VOLUNTEERS to participate in a study...mostly will be students who need the money and therefore it would not represent the actual population and you would have selection bias.

Study design is basically having flaws in the study experiment that generate bias. For example, not having a randomized sample will generate selection bias
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Old 03-25-2012
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Originally Posted by Hope2Pass View Post
Selection bias would be for example, when a researcher decides to ask VOLUNTEERS to participate in a study...mostly will be students who need the money and therefore it would not represent the actual population and you would have selection bias.

Study design is basically having flaws in the study experiment that generate bias. For example, not having a randomized sample will generate selection bias
Not exactly. Students would represent healthy people mostly and are a good cohort for phase I clinical trial.
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Old 03-25-2012
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Not exactly. Students would represent healthy people mostly and are a good cohort for phase I clinical trial.
hmm well that's true for phase 1 clinical trial for a drug but not for a research study. In research study all factors including age, sex, race etc play a factor. With just students, you will not have a random group in terms of AGE for example college or university students.
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Old 03-25-2012
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hmm well that's true for phase 1 clinical trial for a drug but not for a research study. In research study all factors including age, sex, race etc play a factor. With just students, you will not have a random group in terms of AGE for example college or university students.
True, that's randomization. Phase I is a study too.

Selection depends on your study. Randomization is highly important. But for the clinical trial (randomized) you enroll only selective patients, eligible for study criteria.
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True, that's randomization. Phase I is a study too.
haha yeah I guess that's true. But you know what I meant. In regards to USMLE they are just Clinical trials and a research Study
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