Psc 310 final URI
ordinal variable
There is ranking order (liberal ——- conservative)
Times series data vs cross-sectional
Time series data: can be spread out in time Cross-sectional: observations from a certain point in time
Issues that comparative method faces
Too many variables, too few cases Selection bias
Control groups dont recieve treatment
True
Unit of analysis
Frames what is being analyzed as a whole (causality and change)
Bivariate analysis
Has low internal validity and high external validity because sample data is representative of whole population and cant rule out endogeniety or spurriousness
Experimental design typically has ___ levels of internal validity and ___ levels of external validity
High, low *because participants are sample of convenience
Measuremeant validity: face and content
Includes all aspects and elements of a concept Face: Appears to measure what its supposed to Content
Where does causual theory come from?
Induction
Casual theory: induction and deduction
Induction: observing seeking to find patterns pointing to theory Deduction: reasoning from general principals
Internal and external validity
Internal: judges how well research design tested a causal relationship (rulling out spurrious and endogeniety) External: confidence of generalizing finding to real world
Most similar system design
Key is to identify what facor leads to dissimilar outcomes of Y when the cases appear similar mostly
Most different system design
Key is to understand that different unit/cases have the same outcome/Y variable, then find explanatory variable common to the cases that all appear different from eachother
mean, median, mode
Mean: average Median: middle number after ranked Mode: most occuring
nominal variables
No ranking in between categories
Is random sampling required for experiments
No, random assignment is key
4 hurdles of causal theory
1) credible causal mechanism? 2) correlation does not equal causation 3) avoid Y causing X (endogeniety) 4) avoid Z causing X and Y (spurrious)
4 ways to develop good causal theory
1) offer answers 2) be non obvious 3) be nee 4) be general
Standard deviation
Captures how spread out/ dispearsed your data is *more spread =higher standard deviation
Qualitative case study
Costly to study a large number of cases
DV and IV
DV: phenomenon you want to explain (research question) IV: things that can explain phenomenon
Deterministic vs. Probabilistic
Deterministic: cause leads to effect with certainty Probablistic: cause leads to effect with increased probability
Qualitative
Explores causal mechanisms by researching a smaller number of cases
Continuous variable
Ranking order and equal unit differences between categories (age, income)
Normative statement
statement which describes how the world should be "we should have small governments"
measurement bias
the systematic over-reporting or under-reporting of values for a variable
Measurement Reliability
consistency of a measure
Ranking of importance
Valid, reliable, unbiased
Hypothesis
What we expect to observe based on our theory
null hypothesis
What we expect to observe if our theory is uncorrect (no connection/relationship between variables)
