11-21-08

# 11-21-08 - Psychology 206 Class Notes TYPE I ERROR Test...

This preview shows pages 1–2. Sign up to view the full content.

Psychology 206 – Class Notes – 11/21/08 TYPE I ERROR Test statistic z exceeds the critical value and we reject H0 But, H0 is (in reality) TRUE This is type I Error Researcher directly controls probability of Type I error with critical values Probability of Type I error is called alpha (alpha = .05 most common; alpha = .01, alpha= .001) We say: “The probability of Type I error is alpha=.05” Exercise #27 The null hypothesis is that the mean of the population of (birth) weights of infants born to mothers who smoke is greater than or equal to 2.81 kg. The mean of population of (birth) weights of infants born to mothers who smoke is significantly less than 2.81 kg. The null hypothesis is ALWAYS OPPOSITE OF THE ALTERNATIVE HYPOTHESIS. To be sure that your null hypothesis is correct, formulate your alternative hypothesis before you make your null hypothesis. LOOK FOR THE KEY TO EXERCISE #27- Monday Just make sure that you have enough room for your distributions, shade your rejection regions, check your null hypotheses, check your inequalities TYPE II ERROR Type II error is when you fail to reject the null hypothesis when it is really wrong

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

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

### What students are saying

• As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

Kiran Temple University Fox School of Business ‘17, Course Hero Intern

• I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

Dana University of Pennsylvania ‘17, Course Hero Intern

• The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

Jill Tulane University ‘16, Course Hero Intern