PS102Lecture18

PS102Lecture18 - + Statistical Inference and Hypothesis...

Info iconThis preview shows pages 1–8. Sign up to view the full content.

View Full Document Right Arrow Icon
+ Statistical Inference and Hypothesis Testing Political Science 102 Introduction to Political Inquiry Lecture 18
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
+ Hypothesis Testing Procedures
Background image of page 2
+ Factors Influencing Statistical “Significance”
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
+ Errors in Hypothesis Testing In selecting threshold for judging statistical significance, we should balance the costs of type I and type II errors Standard scientific practice is to set threshold for rejecting H0 at 95% (i.e. .05 level) Assumes type II errors are preferable (a conservative standard) Other thresholds may be more appropriate for different problems or applications
Background image of page 4
+ Is it a Toss Up?
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
+ Hypothesis Tests and Sampling Distributions Hypothesis tests depend on estimated confidence intervals for the parameter Confidence interval depends on sampling distribution of the statistic Distributions of variables may differ substantially and idiosyncratically Seems to make problem intractable But we want the sampling distribution of the mean (or some other estimator statistic) NOT sampling distribution of parent variable
Background image of page 6
+ Calculating Confidence Intervals Central Limit Theorem tells us: Sum of a set of random variables approaches a normal distribution as n approaches ∞ Normal distribution is the “bell curve” The mean (and other sample statistics) are sums of random variables
Background image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 8
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 21

PS102Lecture18 - + Statistical Inference and Hypothesis...

This preview shows document pages 1 - 8. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online