WorksheetsSimple/Multiple linear regression - Austin - IPP 3 Exam 2
Total questions: 19
Worksheet time: 15mins
Match the following definitions with their
When not maintained properly leads to bias. controlling for one variable while we change another
Variable control
A form of error. statistical terms/values that do not provide an accurate representation of the population
Bias
Situations in which researchers must accept that some of or all of the design without modification
Nature experiments
A statistical method that allows you to examine the relationship between two or more variables of interest
Regression Analysis
Any factor that prevents appropriate statistical interpretation of a results within practical context of a study
Confounder
Match the following definitions with their descriptions
A specific and observable factor that is omitted from the analysis
Omitted Variable
Fundamentally different estimates then the population parameter
Biased Samples
The unadjusted results when adjustments lead to changes in any estimate of variation
Inefficient
A variable that, when accounted for, leads to a meaningfully different interpretation of relationship between the primary and independent variables and the dependent variables
Confounding effect
Any variable that produces a modifying effect
Effect Modification
Match the following definitions with their descriptions
Statistical adjustments for the cofounder result in
Unbiased Sample
A intermediate between the primary independent variable and the dependent variable that can be used to analyze a relationship
Mediating Effect
Vertical relationship between each data point and trendline
Residual
Simplest process of estimation which assumes dependent variable is continous
Ordinary least squares (OLS)
A value between 0 and 1. As it approaches 0 regression explains very little variation in y. As it approaches 1 it explains it well.
R2
An R2 close to 0 indicates a strong correlation and linear relationship
True
False
Both confounding variables and/or omitted variables can lead to bias
True
False
For which of the following types of data would you use dummy variables?
Patients height
Time spent drinking coffee
Hours spent traveling
Visited another country
You design a study to determine if the numbers of hours watching scrubs correlates to the grade range achieved in IPP3. You also consider other factors such as location, video speed used, and average time snacking. Which of the following is the independent variable
Number of hours watching scrubs
Time snacking
Video speed used
Grade acheived
You design a study to determine if the numbers of hours watching scrubs correlates to the grade range achieved in IPP3. You also consider other factors such as location, video speed used, and average time snacking. Number of hours watching scrubs would be which of the following
Confounding effect
Effect modulator
Mediating effect
None of the above
You design a study to determine if the numbers of hours watching scrubs correlates to the grade range achieved in IPP3. You also consider other factors such as location, video speed used, and average time snacking. Video speed would be which of the following
Confounding effect
Effect moderator
Mediating effect
None of the above
You design a study to determine if the numbers of hours watching scrubs correlates to the grade range achieved in IPP3. You also consider other factors such as location, video speed used, and average time snacking. How would you conduct this study?
Simple regression
Multiple regression
Logistical regression
Survival analysis
You noticed you had some bias in your research study. You choose to make adjustments to decrease the bias. The initial results after the adjustment are
Unbiased
More relliable
inefficient
dependent
You design a study which analyzes the amount of caffeine used by pharmacy students. You randomly collect samples from different students. You notice the parameter estimates and the error terms can be represented by a normal distribution. Can you use OLS?
Yes
No
Ordinal least squares (OLS) can be used for a study which does not use random sampling and the distribution of error term can not be explained by a normal distribution
True
False
Match the following definitions and terms with their descriptions
The omitted variables which if it can be incorporated into regression, the bias/inefficiency associated would be removed
Variable Z
The error term for linear regression. The residual
ε
Adds a penalty for each extra parameter that is added to a model. Might indicate presence of one or more superfluous regressors
Adjusted R2
Additional variables which have no bearing on the study
Superfluous regressor
Represent categories of a discrete variable that are binary in nature.
Dummy Variable
Match the following
Transforms variables to Z-scores allowing for direct comparison
Raw metric form
A variable that influences how the independent variable determines dependent variable
A factor that connects the independent and a dependent variable
The R2 gets smaller as you add in multiple variables
True
False
In multiple linear regression modules we need to use an adjusted R2 value to determine the model of fit
True
False
We can represent a patients weight with dummy variables
True
False
We can represent a patients favorite color with dummy variables
True
False
