University of Massachusetts at Boston

Slides:

Advertisements

Similar presentations

Small differences. Two Proportion z-Interval and z-Tests.

Advertisements

Hypothesis Testing and Comparing Two Proportions Hypothesis Testing: Deciding whether your data shows a “real” effect, or could have happened by chance.

Chi Square Example A researcher wants to determine if there is a relationship between gender and the type of training received. The gender question is.

Section 9.3 Inferences About Two Means (Independent)

Statistical Inference for Frequency Data Chapter 16.

Analysis of frequency counts with Chi square

Statistics for Managers Using Microsoft Excel, 5e © 2008 Prentice-Hall, Inc.Chap 10-1 Statistics for Managers Using Microsoft® Excel 5th Edition Chapter.

1 Difference Between the Means of Two Populations.

Stat 301- Day 32 More on two-sample t- procedures.

Chapter Goals After completing this chapter, you should be able to:

CHARTS IN POWERPOINT Information Technology University of Massachusetts at Boston ©2006William Holmes.

Naked mole rats are a burrowing rodent

Intro to Statistics for the Behavioral Sciences PSYC 1900

PSY 307 – Statistics for the Behavioral Sciences

Hypothesis Testing in SPSS Using the T Distribution

STAT E100 Section Week 10 – Hypothesis testing, 1- Proportion, 2- Proportion – Z tests, 2- Sample T tests.

Analysis of Variance. v Single classification analysis of variance determines whether a relationship exists between a dependent variable and several classifications.

1 Tests with two+ groups We have examined tests of means for a single group, and for a difference if we have a matched sample (as in husbands and wives)

Comparing Two Population Means

Famous People Challenge Look at the picture. Write down the person’s name. We will check the answers at the end. Five parts: famous men, famous women,

T- and Z-Tests for Hypotheses about the Difference between Two Subsamples.

 People have said that video games can actually improve your hand-eye coordination  Wanted to see whether this hypothesis was true.

Chi-Square Distributions. Recap Analyze data and test hypothesis Type of test depends on: Data available Question we need to answer What do we use to.

Advanced Math Topics Chapter 10 Review. a) SectionGivensSteps Tests Concerning Means for Large Samples -population or claim average and σ 1) 2) 2-tail.

Chi Square Classifying yourself as studious or not. YesNoTotal Are they significantly different? YesNoTotal Read ahead Yes.

Normal Distribution Links The Normal Distribution Finding a Probability Standard Normal Distribution Inverse Normal Distribution.

Foundations of Sociological Inquiry Statistical Analysis.

Testing Differences between Means, continued Statistics for Political Science Levin and Fox Chapter Seven.

Practical Statistics Chi-Square Statistics. There are six statistics that will answer 90% of all questions! 1. Descriptive 2. Chi-square 3. Z-tests 4.

Remember Playing perfect black jack – the probability of winning a hand is.498 What is the probability that you will win 8 of the next 10 games of blackjack?

DATA DESCRIPTION Research Methods College of Public and Community Services University of Massachusetts at Boston ©2012 William Holmes 1.

- We have samples for each of two conditions. We provide an answer for “Are the two sample means significantly different from each other, or could both.

Results: How to interpret and report statistical findings Today’s agenda: 1)A bit about statistical inference, as it is commonly described in scientific.

Degrees of freedom. This number is one less than the total number of classes of offspring in a cross. In a monohybrid cross, such as our Case 1, there.

Bullied as a child? Are you tall or short? 6’ 4” 5’ 10” 4’ 2’ 4”

Obesity and Socioeconomic Status in Adults: United States, 2005–2008 NCHS Data Brief ■ No. 50 ■ December 2010.

Flossing Analysis. Introduction Sampling Methods Descriptive Statistics Checking Requirements Inferential Statistics Conclusion Flossing Analysis.

Dowel Balancing Summer There were three independent variables The hand in which the dowel was placed (left or right) The verbal task (no talking,

AP Statistics Chapter 24 Notes “Comparing Two Sample Means”

Chapter 131 Normal Distributions. Chapter 132 Thought Question 2 What does it mean if a person’s SAT score falls at the 20th percentile for all people.

MATH Section 7.5.

Statistical Significance or Hypothesis Testing. Significance testing Learning objectives of this lecture are to Understand Hypothesis: definition & types.

The  2 (chi-squared) test for independence. One way of finding out is to perform a  2 (chi-squared) test for independence. We might want to find out.

Seven Steps for Doing  2 1) State the hypothesis 2) Create data table 3) Find  2 critical 4) Calculate the expected frequencies 5) Calculate  2 6)

Differences between t-distribution and z-distribution

Lecture #19 Tuesday, October 25, 2016 Textbook: Sections 12.3 to 12.4

Background: The age old question to Mr

A gender sensitive organization should meet the following criteria in its practices: First, the balance of women and men on the staff should include a.

Hypothesis Tests Small Sample Mean

Hypothesis Testing Review

Two Sample Tests When do use independent

Types of T-tests Independent T-tests Paired or correlated t-tests

University of Massachusetts at Boston

Two Way ANOVAs Factorial Designs.

In Canada, suicide is among the top causes of death for youth and young adults. For males 15 to 19 years of age, there was a 23% decline in the suicide.

Is a persons’ size related to if they were bullied

Consider this table: The Χ2 Test of Independence

WARM - UP 1. How do you interpret a Confidence Interval?

The 2 (chi-squared) test for independence

Warm Up Your textbook provides the following data on the height of men and women. Mean Std. Dev Men Women ) What is the z score.

A paired-samples t-test compares the means of two related sets of data to see if they differ statistically. IQ Example We may want to compare the IQ scores.

Comparing Two Populations

Chi-square problem solutions

MATH 2311 Section 7.5.

1. What animal 2. Male or Female ? 4. Male or Female? Why? Why?

IENG 486 Statistical Quality & Process Control

Warm Up Your textbook provides the following data on the height of men and women. Mean Std. Dev Men Women ) What is the z score.

MATH 2311 Section 7.5.

Presentation transcript:

University of Massachusetts at Boston T-TEST Research Methods University of Massachusetts at Boston ©2006 William Holmes

T-TEST: COMPARING TWO GROUP MEANS Set criterion (alpha level). Check group frequencies, means, and standard deviations. Compare means for each group. Examine t-value, degrees of freedom, and significance probability. If probability smaller that alpha level, difference is significant.

EXAMPLE 1: t-test Mental Health by Sex Males Females 29.7 31.8 25 27 3.96 4.11 . Mean N Std. Dev. Difference of Means=2.1 Are women healthier than men?

EXAMPLE 1(cont’d.): t-test Mental Health by Sex Males Females 29.7 31.8 25 27 3.96 4.11 . Mean N Std. Dev. Difference of Means=2.1 t=1.89, d.f.=48, P=.06 Answer: Women are not healthier than men.