POLS 3312 Final Exam correctly
answered to pass
internal validity - correct answer ✔✔- The ability to show the manipulation or variation of the
independent variable actually causes the dependent variable to change
Internal Validity Threats - correct answer ✔✔- The "treatment" or the "independent" variable is
showing an effect, but the effect is not real. The effect is due to a flaw in the research design are
is artificially creating the perceived "effect." Or the treatment is showing no effect, when there
is an effect. Note these are mistake in the research design.
external validity - correct answer ✔✔- The ability to generalize from one set of research findings
to other situations
External Validity Threats - correct answer ✔✔- The effect in the study is real, but it cannot be
generalized to a larger population.
What does the term "spurious" mean? - correct answer ✔✔- is one in which the association
between two variables is caused by a third.
- A relationship arises because two things are both affected by a third factor and thus appear to
be related
What conditions must be met to infer "cause" in a research design? - correct answer ✔✔- The
ONLY WAY we can infer cause in a non-experimental design in thought statistical control. We
hold constant the variable we think is "confounding" is some way our two variable relationship.
- To infer cause in a non-experimental design we have to rule out as many alternative
explanations as possible.
, -What we need to think about is how are we going to rule out possible alternative explanations?
First, we have to propose them. Given a finding that X is associated with Y and is statistically
significant, what else could be associated with Y?
What is meant by random assignment in an experimental design, and why is it important? -
correct answer ✔✔- assigning subjects to groups not according to one of their characteristics
such as gender or age, under the assumption that extraneous factors will affect all groups
equally and thus "cancel out".
- is an especially attractive choice when it is not possible to specify possible extraneous factors
in advance or when there are so many assigning subjects to experimental and control groups in
a manner that ensures the equal distribution of these factors is not possible
null hypothesis - correct answer ✔✔- A statement that a population parameter equals a single
or specific value; the hypothesis that there is no relationship between two variables in the
target population. Often, a statement that the difference between two populations is zero.
What is a sampling distribution? What is it used for? - correct answer ✔✔- A theoretical
(nonobseverved) distribution of sample statistics calculated on samples of of size N that, if
known, permits the calculation of confidence intervals and the test of statistical hypotheses
According to the author of Naked Statistics, how do we "fit" data to a regression line? - correct
answer ✔✔-Ordinary least square: fits the line that minimizes the sum of the squared residuals
How does the author of Naked Statistics define "margin of error" in a public opinion poll? -
correct answer ✔✔- In a confidence interval, the range of values above and below the sample
statistic
What does the author of Naked Statistics say is the best way to draw a sample for a public
opinion poll? - correct answer ✔✔- that the sampling statistic we care about will be not a mean
but rather a percentage or proportion
answered to pass
internal validity - correct answer ✔✔- The ability to show the manipulation or variation of the
independent variable actually causes the dependent variable to change
Internal Validity Threats - correct answer ✔✔- The "treatment" or the "independent" variable is
showing an effect, but the effect is not real. The effect is due to a flaw in the research design are
is artificially creating the perceived "effect." Or the treatment is showing no effect, when there
is an effect. Note these are mistake in the research design.
external validity - correct answer ✔✔- The ability to generalize from one set of research findings
to other situations
External Validity Threats - correct answer ✔✔- The effect in the study is real, but it cannot be
generalized to a larger population.
What does the term "spurious" mean? - correct answer ✔✔- is one in which the association
between two variables is caused by a third.
- A relationship arises because two things are both affected by a third factor and thus appear to
be related
What conditions must be met to infer "cause" in a research design? - correct answer ✔✔- The
ONLY WAY we can infer cause in a non-experimental design in thought statistical control. We
hold constant the variable we think is "confounding" is some way our two variable relationship.
- To infer cause in a non-experimental design we have to rule out as many alternative
explanations as possible.
, -What we need to think about is how are we going to rule out possible alternative explanations?
First, we have to propose them. Given a finding that X is associated with Y and is statistically
significant, what else could be associated with Y?
What is meant by random assignment in an experimental design, and why is it important? -
correct answer ✔✔- assigning subjects to groups not according to one of their characteristics
such as gender or age, under the assumption that extraneous factors will affect all groups
equally and thus "cancel out".
- is an especially attractive choice when it is not possible to specify possible extraneous factors
in advance or when there are so many assigning subjects to experimental and control groups in
a manner that ensures the equal distribution of these factors is not possible
null hypothesis - correct answer ✔✔- A statement that a population parameter equals a single
or specific value; the hypothesis that there is no relationship between two variables in the
target population. Often, a statement that the difference between two populations is zero.
What is a sampling distribution? What is it used for? - correct answer ✔✔- A theoretical
(nonobseverved) distribution of sample statistics calculated on samples of of size N that, if
known, permits the calculation of confidence intervals and the test of statistical hypotheses
According to the author of Naked Statistics, how do we "fit" data to a regression line? - correct
answer ✔✔-Ordinary least square: fits the line that minimizes the sum of the squared residuals
How does the author of Naked Statistics define "margin of error" in a public opinion poll? -
correct answer ✔✔- In a confidence interval, the range of values above and below the sample
statistic
What does the author of Naked Statistics say is the best way to draw a sample for a public
opinion poll? - correct answer ✔✔- that the sampling statistic we care about will be not a mean
but rather a percentage or proportion
