"The Process of Statistics: Side Effects In clinical trials of...

Question

"The Process of Statistics: Side Effects In clinical trials of the allergy medicine Clarinex (5 mg), 3307 allergy sufferers were randomly assigned to either a Clarinex group or a placebo group. It was reported that 50 out of 1655 individuals in the Clarinex group and 31 o

ut of 1652 individuals in the placebo group experienced dry mouth as a side effect of their respective treatments. Source: www.clarinex.com

b. What is the response variable? Is it qualitative or quantitative?"

Accepted Answer

Welcome back, everyone. In a workplace ergonomic trial, 540 office workers were randomized to receive either an ergonomic chair or a standard chair. Researchers recorded whether each worker reported a new onset of lower back pain after 6 months. They found 12 of 270 in the ergonomic cheer group and 35 of 270 in the standard cheer group reported pain. Identify the response variable and state its type. A says the response variable is the number of 6 days, and it's quantitative. B says it's the chair type and it's qualitative. C says it's the severity of back pain on a 0 to 10 scale and quantitative. And D says it's new lower back pain and is qualitative. Now, before we answer this question, let's first ask ourselves what we know about response variables and types of data. Now the response variable, let's just make those notes on the right. The response variable. Is the man. Measured outcome, OK? So it's what we are measuring basically. And the data type can be either quantitative, OK, quantitative or qualitative. Where quantitative data is numeric, OK, and qualitative data is categoric. So the question is, when we look at our information that we're given, what are we measuring and is it numeric or categoric? Well, if we take a, take note here, the study recorded whether each worker reported new lower back pain. So the response is new lower back pain, where. They would basically be saying, let me, let me highlight that here. They're reporting a new onset of lower back pain, where pretty much they're either saying yes they did or no they did not. Therefore, new lower back pain is the response variable, and it is qualitative because it has categories rather than numeric values. If we look back at our answer choices, that means D is the correct answer. We can be surer right by reviewing the remaining choices. In choice A, it says the variable is the number of sick days taken and that data is quantitative. Now, the reported data are accounts of workers reporting pain, not sick days. So the number of sick days is not the response variable here, even though admittedly it would be a quantitative variable. In choice B It says that the response variable is the cheer type and it is qualitative, but the group assignment is an explanatory variable in randomized trials. Therefore, the cheer type is not the response variable, even though it is qualitative. They're not giving them or telling them what your type uh after um what your type they have like that's not what they're answering, right? And in choice C it says that the response variable is the severity of back pain on a 0 to 10 scale, which is quantitative, but a numeric scale outcome would be quantitative. The study did not report pain severity scores, so severity on a scale of 0 to 10 is not the response variable. So that's how we know that D is the correct answer. Thanks a lot for watching everyone. I hope this video helped.

Key Concepts

Response Variable

Qualitative vs. Quantitative Variables

Random Assignment in Experiments

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