# Shared Flashcard Set

## Details

The Scientific Method
File 3
21
Veterinary Medicine
Professional
01/15/2015

Term
 Definition: Law
Definition
 -appears without exception; has become consolidated by repeated successful testing; often expressed in concise verbal or mathematical statement
Term
 Definition: Theory
Definition
 -scientifically accepted general principle supported by substantial body of evidence; provides explanation of observed facts/events and basis for future investigation
Term
 Definition: Hypothesis
Definition
 -a specific statement or question to be evaluated
Term
 Does one study ever prove anything?
Definition
 -no
Term
 True or False: Scientifically, we cannot prove anything.
Definition
 TRUE
Term
 Definition: Null hypothesis
Definition
 -there is no linkage b/n the things we are researching
Term
 Definition: Independent variables
Definition
 -the variables we change
Term
 Definition: Dependent variables
Definition
 -the outcome
Term
 Definition: True status
Definition
 -existence of difference (association, disease, etc)
Term
 What are the 4 possible outcomes of a study?
Definition
 1) The study detected a difference when it existed (correct conclusion)2) Type I error: rejected null hypothesis when it was true (did not detect a difference that was there)3)Type II error: failed to reject null hypothesis when it was false (detected a difference when there wasn't one)4) didn't detect a difference when there wasn't one
Term
 The probability finding is due to chance and is compared to pre-established _______ to determine significance.
Definition
 -alpha value
Term
 Definition: Beta
Definition
 -probability of a type II error
Term
 Definition: 1- Beta
Definition
 -Power, the probability of rejecting null hypothesis when it is false
Term
 How can a wrong conclusion be made in a well-designed study?
Definition
 -by using a small group of subjects to represent the population of interest
Term
 What is the significance of the bellcurve?
Definition
 -for many characteristics in the world, there will be an average value and variation in the population (standard deviation)
Term
 How should one go about selecting a sample to avoid bias? When is this altered?
Definition
 -best way is random selection-altered is you must block a specific factor to not skew the results (age, gender, breed, location, etc)
Term
 How do we extimate the probability of finding a difference this larger, or larger, if the null is true?
Definition
 -estimate P-value
Term
 How do we determine if findings are significant?
Definition
 -compare calculated P-value to pre-determined alpha threshold (0.05)
Term
 Explain what happens to the power if the following occurs:a)higher alphab)stronger associationc)larger sample sized)larger variation among population
Definition
 a)increases powerb)increases powerc)increases powerd)decreases power
Term
 Are all statistically significant findings clinically relevant?
Definition
 -no, small differences may e found that would not change your clinical judgement
Term
 Are all clinically relevant findings statistically significant?
Definition
 -no (low power of study), there are important differences that WOULD alter your clinical judgment that could be missed
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