# Shared Flashcard Set

## Details

pols2072q
prof sam best
41
Political Studies
05/05/2010

Term
 Unit of Analysis
Definition
 entity we want to describe
Term
 Random Measurement Error
Definition
 chaotic distortion of an empirical measurement
Term
 Internal Validity
Definition
 within the conditions artificially created by the researcher, the effect of the independent variable on the dependent variable is isolated from other plausible explanations
Term
 Normal Distribution
Definition
 distribution used to describe internal-level variables
Term
 Exact median
Definition
 treats the cases in the median category as uniformly distributed across the interval and adjusts the median in the direction of the 50th percentile
Term
 Dispersion
Definition
 variation of spread of cases across its values
Term
 Population
Definition
 universe of cases the researcher wants to describe
Term
 Degrees of Freedom
Definition
 refers to a statistical property of a large family of distributions.
Term
 Zero-Order Relationship
Definition
 a difference obtained from a simple comparison
Term
 Ecological fallacy
Definition
 an error int he interruption of data whereby inferences about the nature of specific individuals are based solely upon aggregate statistics collected for the group to which those individuals belong
Term
 Concept
Definition
 idea that represents phoenomena in the real world
Term
 External Validity
Definition
 results of a study can be applied to situations in the real world
Term
 Central Tendency
Definition
 identifies the most representative value of the distribution (mode, median, mean)
Term
 Trimmed Mean
Definition
 removes the most extreme observations before comupting the mean
Term
 Coefficient of Association
Definition
 reflects the strength and direction of association between two variables
Term
 Random Assignment
Definition
 each subject has an equal chance of being picked for the test of control group
Term
 Confidence Interval
Definition
 researcher uses the standard error to determine the smallest plausible mean difference in the population. If the smallest difference is greater than 0, the null hypothesis can be rejected
Term
 Selection Bias
Definition
 occurs when the subjects in the test group are different from subjects in the control group
Term
 Partial Effect
Definition
 summarizes a relationship between two variables after taking rival variables into account
Term
 Systematic Measuement Error
Definition
 consistent, chronic distortion of an empirical measurement
Term
 Variable
Definition
 dependent variable represents the effect in an explanation and an independent variable represents the cause of the explanation
Term
 Rival Explanations
Definition
 other plausible causes for different values of the dependent variable
Term
 Refined Mode
Definition
 deals with a grouped frequency distribution. Adjusts crude mode by considering the frequencies of the intervals adjacent to the model interval
Term
 Percentile
Definition
 reports the percentage of cases in a distribution that lie below it
Term
 Sample
Definition
 a number of cases or observations drawn from a population
Term
 Random Selection
Definition
 when every member of a potential sample population has an equal chance of being included in the sample
Term
 Margin of Error
Definition
 amount of random sampling error in a surveys result
Term
 Control Variable
Definition
 variable that is held constant or whose impact is removed in order to analyze the relationshop between other variables without interference
Term
 Critical Value
Definition
 the upper plausible boundary of random error
Term
 Four Stages of the Measurement Process
Definition
 a. Concept b. Conceptual Definition C. Operational Definition D. Variable
Term
 Conceptual Definition
Definition
 describe's a concept's properties
Term
 Operational Definition
Definition
 describes how the concept is to be measured empirically
Term
 3 levels of precision
Definition
 Nominal: no regard to rank or distance Ordinal: rank but no regard to distance Interval: rank and distance matter
Term
 Reliability
Definition
 extent to which it is a consistent measure of a concept
Term
 Validity
Definition
 extent to which true vlue of characteristic is recorded
Term
 Approaches to evaluate reliability
Definition
 test-retest method: apply measure at 2 different points in time to same group of subjects split half method: divide test in half for gorup to assess
Term
 Approaches to evaluate validity
Definition
 Face validity: closely examine operational procedure and relies on informed judgment Constuct Validity: assess the association between the measure of concept and another related concept
Term
 Explanatory Process
Definition
 1. Variable 2. Explanation 3. State Hypothesis 4. Test Hypothesis
Term
 3 types of research design
Definition
 lab experiment field experiment natural experiment
Term
 Variation Ratio
Definition
 describes the percentage of all cases that do not fall into the modal category
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