Hypothesis Testing.

Slides:



Advertisements
Similar presentations
Introduction to Hypothesis Testing
Advertisements

 When we perform a hypothesis test, we make a decision to either Reject the Null Hypothesis or Fail to Reject the Null Hypothesis.  There is always the.
Statistics 101 Class 8. Overview Hypothesis Testing Hypothesis Testing Stating the Research Question Stating the Research Question –Null Hypothesis –Alternative.
Statistical Significance What is Statistical Significance? What is Statistical Significance? How Do We Know Whether a Result is Statistically Significant?
HYPOTHESIS TESTING Four Steps Statistical Significance Outcomes Sampling Distributions.
Hypothesis Testing Steps of a Statistical Significance Test. 1. Assumptions Type of data, form of population, method of sampling, sample size.
Statistical Significance What is Statistical Significance? How Do We Know Whether a Result is Statistically Significant? How Do We Know Whether a Result.
Power. The Four Components to a Statistical Conclusion The number of units (e.g., people) accessible to study The salience of the program relative to.
Power and Effect Size.
Hypothesis Testing: Type II Error and Power.
Hypothesis Testing for the Mean and Variance of a Population Introduction to Business Statistics, 5e Kvanli/Guynes/Pavur (c)2000 South-Western College.
Introduction to Testing a Hypothesis Testing a treatment Descriptive statistics cannot determine if differences are due to chance. A sampling error occurs.
© 2002 Thomson / South-Western Slide 9-1 Chapter 9 Hypothesis Testing with Single Samples.
Hypothesis Testing – Introduction
Hypothesis testing is used to make decisions concerning the value of a parameter.
Descriptive statistics Inferential statistics
8 - 1 © 2003 Pearson Prentice Hall Chi-Square (  2 ) Test of Variance.
Chapter 8 Introduction to Hypothesis Testing
Hypothesis Testing (Statistical Significance). Hypothesis Testing Goal: Make statement(s) regarding unknown population parameter values based on sample.
Means Tests Hypothesis Testing Assumptions Testing (Normality)
Overview Basics of Hypothesis Testing
1 Power and Sample Size in Testing One Mean. 2 Type I & Type II Error Type I Error: reject the null hypothesis when it is true. The probability of a Type.
Elementary Statistical Methods André L. Souza, Ph.D. The University of Alabama Lecture 22 Statistical Power.
Chapter 9 Hypothesis Testing II: two samples Test of significance for sample means (large samples) The difference between “statistical significance” and.
Learning Objectives In this chapter you will learn about the t-test and its distribution t-test for related samples t-test for independent samples hypothesis.
1 Lecture note 4 Hypothesis Testing Significant Difference ©
Hypothesis testing and Decision Making Formal aspects of hypothesis testing.
Inferential Statistics Body of statistical computations relevant to making inferences from findings based on sample observations to some larger population.
Correct decisions –The null hypothesis is true and it is accepted –The null hypothesis is false and it is rejected Incorrect decisions –Type I Error The.
Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall Statistics for Business and Economics 8 th Edition Chapter 9 Hypothesis Testing: Single.
Education 793 Class Notes Decisions, Error and Power Presentation 8.
Power Analysis for Traditional and Modern Hypothesis Tests
Formulating the Hypothesis null hypothesis 4 The null hypothesis is a statement about the population value that will be tested. null hypothesis 4 The null.
Introduction to Hypothesis Testing
Introduction to Testing a Hypothesis Testing a treatment Descriptive statistics cannot determine if differences are due to chance. Sampling error means.
Univariate Statistics PSYC*6060 Class 2 Peter Hausdorf University of Guelph.
Major Steps. 1.State the hypotheses.  Be sure to state both the null hypothesis and the alternative hypothesis, and identify which is the claim. H0H0.
Power of a test. power The power of a test (against a specific alternative value) Is In practice, we carry out the test in hope of showing that the null.
Hypothesis Testing Steps for the Rejection Region Method State H 1 and State H 0 State the Test Statistic and its sampling distribution (normal or t) Determine.
BHS Methods in Behavioral Sciences I May 9, 2003 Chapter 6 and 7 (Ray) Control: The Keystone of the Experimental Method.
Chapter 9: Hypothesis Tests for One Population Mean 9.2 Terms, Errors, and Hypotheses.
PEP-PMMA Training Session Statistical inference Lima, Peru Abdelkrim Araar / Jean-Yves Duclos 9-10 June 2007.
Lec. 19 – Hypothesis Testing: The Null and Types of Error.
More about tests and intervals CHAPTER 21. Do not state your claim as the null hypothesis, instead make what you’re trying to prove the alternative. The.
McGraw-Hill/Irwin © 2003 The McGraw-Hill Companies, Inc.,All Rights Reserved. Part Four ANALYSIS AND PRESENTATION OF DATA.
Ex St 801 Statistical Methods Part 2 Inference about a Single Population Mean (HYP)
Learning Objectives Describe the hypothesis testing process Distinguish the types of hypotheses Explain hypothesis testing errors Solve hypothesis testing.
Part Four ANALYSIS AND PRESENTATION OF DATA
Hypothesis Testing I The One-sample Case
Example: Propellant Burn Rate
Hypothesis Testing – Introduction
Hypothesis Testing: Hypotheses
MATH 2311 Section 8.2.
اختبار الفرضيات اختبارالفرضيات المتعلقة بالوسط
P-value Approach for Test Conclusion
Chapter 9 Hypothesis Testing
Chapter 9: Hypothesis Testing
AP Statistics: Chapter 21
Chapter 9: Hypothesis Tests Based on a Single Sample
Hypothesis Tests for Proportions
Hypothesis Testing.
Chapter 11: Introduction to Hypothesis Testing Lecture 5c
Power Section 9.7.
More About Tests Notes from
Chapter 8 Making Sense of Statistical Significance: Effect Size, Decision Errors, and Statistical Power.
Sample Mean Compared to a Given Population Mean
Sample Mean Compared to a Given Population Mean
Testing Hypotheses I Lesson 9.
Inference as Decision Section 10.4.
Statistical Power.
Presentation transcript:

Hypothesis Testing

Hypothesis Testing We talked about this the first day. Let’s talk more about it now. Four steps: Formulate Null hypothesis and Alternative hypothesis (hypothesis) Obtain sampling distribution and rejection regions (population) Calculate test statistic from your data (sample) Compare the test statistic to rejection regions (if within rejection region, then significant)

Hypothesis Formulate Null and Alternative hypothesis Null hypothesis H0 : Population means equal If two groups: m1 = m2 If three+ groups: m1 = m2 = m3 = m4 Alternative hypothesis: H1 : mean NOT equal If two groups:: m1 ≠ m2 If three+ groups: m1 ≠ m2 ≠ m3 ≠ m4 As a researcher, you want to reject the “null”.

Errors in Hypothesis Testing REALITY H0 is true (n.s.) H0 is false (sig) Probability = a Probability = (1 - b) Reject H0 (sig) (test statistic is in Rejection region) Type I error, or “False Alarm” Correct Decision POWER OUTPUT FROM SPSS Fail to Reject H0 (n.s.) Probability = b I GOT THIS SLIDE FROM SOMEWHERE, NOT MINE Probability = (1 - a) (test statistic is not in Rejection region) Type II error, or a “miss” Correct Decision

Factors Increasing Power: (1) Increasing alpha level (e.g., .05 to .09) (2) Increasing difference between means (3) Reducing between-group variation (4) Increasing sample size