poli

a working directory used by R should include

the date u wnat to analyze + the .R and .RMD files that contain your commands. (both a and b)

external validity

the degree to which we can be confident that our results apply to other contexts

what summarizes the main goal of political science?

the development and evaluation of causal theories about politics

which of the following describes a continuous variable?

(1) a one-unit increase in the variable value always means the same thing (2) different values mean different things

which of the following are the basis of causality in a theory

(1) time ordering; cause precedes effect (2) co-variation: change in X associated with change in Y (3) non-spuriousness: there is no variable Z that causes both X+Y (ALL OF THE ABOVE)

which of the following are properties about probability?

ALL OF THE ABOVE: if, and only if, two outcomes are independent, then the probability of both of those events occurring is equal to the product of them individually; all outcomes have some probability ranging between zero and one and the sum of all possible outcomes must be exactly one

which of the following statements are accurate about the sample regression model?

E is the stochastic component of Y; A+B is the systematic component of Y (bOTH A & B CORRECT)

which of the following is not true about the R-squared statistic?

The R-squared statistic tells us how likely that there is a causal relationship between x and y

why is conceptual clarity an important first step in the measurement process?

because, without clear definitions of the concepts we intend to measure, its impossible to know whether the measures accurately capture what we intend to measure

a random sample is an example of...

a probability sample

which of the following is true regarding p-values

all of the above (1) it represents the probability that we would see the relationship that we are finding because of random chance (2) it represents the probability that we would see the observed relationship between the two variables in our sample date if there were truly no relationship between them in the unobserved population (3) the lower the p-value, the greater confidence we have that there is a systematic relationship between the two variables (4) it represents the level of confidence with which we can reject the null hypothesis

which of the following describes an empirical assertion?

an assertion of "what is"

which is an example of a negative relationship?

as military spending goes up, welfare spending goes down (as one increases, the other decreases)

why is it so critical for researchers to try to control for confounding variables?

because the failure to do so may lead to the wrong conclusion about the real relationship between x and y

What is one thing to remember from this class

correlation does not equal causation

establishing that there is a credible causal mechanism that links X to Y involves..

it forces the researcher to consider exactly how and why X might affect Y

which of the following is true if a study used random sampling to select its participants?

it means that every member of the population had an equal probability of being selected to participate in the study

In a normal distribution, the mean of a variable is:

the most frequently occurring value, the average value and the first moment

in statistics, Greek letters are usually used to indicate

the population parameter

inference

the process of using what we know about learning what we do not know is:

what is operationalization?

the specific ways in which a theoretical concept is measured using real-world observations

if a researcher finds results in the direction expected by his or her hypothesis which of the following describes what has happened

their theory has been supported

which of the following accurately describes a difference of means test

this is a test is used when we want to test whether the value of a continuous dependent variable is different across values of a categorical independent value

what is the most important purpose of a research design?

to most effectively control for as many confounding variables as possible, thus leaving the relationship between x and y unpolluted by outside influences

the best fitting regression line minimizes the sum of the squared residuals

true