The two critical elements required to sign the bias of an omitted variable include the sign of the:
A. effect of the omitted variable on the outcome and the sign of the correlation between the omitted variable and the treatment.
B. correlation between the omitted variable and the outcome and the sign of the correlation between the treatment variable and the outcome.
C. effect of the omitted variable on the outcome and the sign of the correlation between the omitted variable and the outcome.
D. effect of the omitted variable on the outcome and the sign of the effect of the treatment variable on the outcome.
Answer: A
You might also like to view...
You are in a lab studying a new cell type that has been discovered. You observe a rigid cytoskeleton in this cell, along with a nucleus and a compartmentalized interior. How would you classify this cell?
A. as an advanced prokaryotic cell, because it has a rigid cytoskeleton B. as a primitive prokaryotic cell C. as a possible transitional cell from prokaryotic to eukaryotic D. as a eukaryotic cell that has to be heterotrophic E. None of the answers options is correct.
Organisms that can manufacture their own chemical energy are called ________.
A. oligotrophs B. heterotrophs C. autotrophs D. chemotrophs
A phospholipid molecule has a polar and a nonpolar end. Because of this, water molecules form
A. polar bonds with the nonpolar end of the phospholipid molecule. B. polar bonds with the polar end of the phospholipid molecule. C. covalent bonds with the nonpolar end of the phospholipid molecule. D. hydrogen bonds with the nonpolar end of the phospholipid molecule. E. hydrogen bonds with the polar end of the phospholipid molecule.
Culturing of intracellular parasites generally requires (enrichment/cell culture/low oxygen) conditions.
Fill in the blank(s) with the appropriate word(s).