CH. 1 - Benefits & Risks of Using Statistics PDF

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Psych Stats: CH. 1—The Benefits and Risks of Using Statistics  Statistical methods used to analyze situations involving uncertainty and natural variation o Find differences o Find patterns and relationships  Statistics – collection of procedures/principles for gaining and analyzing information to educate people/help make good decisions when dealing with uncertainty o Satisfy our curiosity of the world - To conduct a good statistical study: 1) Get a representative sample a. Pool together participants who represent the larger group which conclusions are drawn  Sample – those actually studied  Population – larger group sample is taken from 2) Get a large enough sample a. “How large enough” tied to how diverse measurements are likely in each group  *more diverse individuals, need a larger sample* 3) Observational study or randomized experiment  Observational experiment – observe things in our sample  Randomized experiment – randomly assign people to one of two groups  *how to make casual connection* - Examples of Improper Statistics o Robotic Polls  no representative sample! o Toxic Chemicals  stats taken out of proper context! o Mom’s Smoking and Kids IQs  too strong conclusion on basis of observational study

SUMMARY: examined advantages/dangers of statistical methods. Must know how to study/experiment’s numbers were collected and who asked

REVIEW: - Cause and effect conclusions can’t be made on observational study results  Problem: groups being studied likely to differ - Randomized experiments can lead to cause and effect conclusions. Random assignment puts everyone on equal playing field - Association no = causation - Measurement error important bias source in data - Population of extension  determine based on how data collected...