Introduction to Statistics for the Social Sciences SBS200, COMM200, GEOG200, PA200, POL200, or SOC200 Lecture Section 001, Spring 2016 Room 150 Harvill Building 9:00 - 9:50 Mondays, Wednesdays & Fridays Welcome

By the end of lecture today 4/4/16 Review for Exam 3

Before next exam (April 8th) Please read chapters 1 - 11 in OpenStax textbook Please read Chapters 2, 3, and 4 in Plous Chapter 2: Cognitive Dissonance Chapter 3: Memory and Hindsight Bias Chapter 4: Context Dependence Study guide is online Review worksheet is also available online

To your TA during lecture Hand in your project 3 To your TA during lecture

Lab sessions Everyone will want to be enrolled in one of the lab sessions No Labs this week

Remember, it never will be if the observed t is less than one Yes, p < .05, reject the null and it is a significant difference No, p is not < .05, do not reject the null and there is no significant difference No, p is not < .05, do not reject the null and there is no significant difference Remember, it never will be if the observed t is less than one small observed t score

or decrease level of confidence Decrease variability or decrease level of confidence It is easier to reject the null It gets narrower Easier; use a one-tail test when you have a unidirectional prediction Use a t-test when don’t know population standard deviation and only have sample standard deviation (Same is true for variance or variability)

Type of cartoon will not affect level of aggression Two-tail True 48 2.011 Type of cartoon will not affect level of aggression Type of cartoon will affect level of aggression Type of cartoon will not affect aggression when it fact it will Type of cartoon will affect aggression when it fact it will not

Common and rare scores Go down from .05 to .01 Mean approaches the true population mean Shape approaches normality Variability goes down No, never reject null if the prediction in a one-tailed test is wrong

78 79 14 71.7142 The mean test scores were 78 for the men and 79 for the women enrolled in Dr. Rubio’s class. A t-test was conducted and no significant difference was found, t(14) = -0.23; n.s.

12 3 25 100 4 3.49 Yes Yes The mean home prices were compared for these four neighborhoods. The average selling price was 65.5 million dollars in the Southpark neighborhood, 71 million dollars in the Northpark neighborhood, 77.25 million dollars for the Westpark neighborhood and 74.75 million dollars for the Eastpark neighborhood. An ANOVA was conducted and a significant main effect was found, F(3,12) = 4.00; p < 0.05.

27 2 40 6.518 6.1 3.35 Yes Yes The mean number of cookies sold was 10 boxes for the girl scouts offered no incentive, 12 boxes for the girl scouts offered a new bike and 14 boxes for girl scouts offered a trip to Hawaii. An ANOVA conducted and a significant main effect was found, F(2, 27) = 6.14; p < 0.05

95% 42 58 42.16 57.40

Thank you! See you next time!!