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

Before next exam (March 4 th ) Please read chapters in OpenStax textbook Please read Chapters 10, 11, 12 and 14 in Plous Chapter 10: The Representativeness Heuristic Chapter 11: The Availability Heuristic Chapter 12: Probability and Risk Chapter 14: The Perception of Randomness Schedule of readings

By the end of lecture today 2/15/16 Overview of Project 2 What are the main objectives in completing research in any area?

Everyone will want to be enrolled in one of the lab sessions Labs continue With Project 2

Exam 1 – This past Friday Thanks for your patience and cooperation We should have the grades up by Friday (takes about a week) It went really well!

. Example of a study Who is taller men or women? Independent Variable? Dependent Variable? IV: Nominal Ordinal Interval or Ratio? DV: Nominal Ordinal Interval or Ratio? IV: Continuous or discrete? DV: Continuous or discrete? Gender Height IV: Nominal DV: Ratio IV: Discrete DV: Continuous This is an example of a _____. a. correlation b. t-test c. one-way ANOVA d. two-way ANOVA t-test

. Example of t-test Who is taller men or women? How would you state no difference between groups? No difference in the height between men and women Directional? (predicting who is taller?) Between Or within? Quasi or True? Non- directional Between Quasi This is called the “null hypothesis” How would you state yes difference between groups? Yes there is a difference in the height between men and women This is called the “rejecting the null hypothesis”

. Example of t-test Who is taller men or women? How would you state no difference between groups? No difference in the height between men and women What if you are wrong What if you are wrong? Type II Error or “miss” Type I Error “false alarm” How would you state yes difference between groups? Yes there is a difference in the height between men and women

. Example of a study This is an example of a _____. a. correlation b. t-test c. one-way ANOVA d. two-way ANOVA t-test Independent Variable? Dependent Variable? IV: Nominal Ordinal Interval or Ratio? DV: Nominal Ordinal Interval or Ratio? IV: Continuous or discrete? DV: Continuous or discrete? Curly vs straight hair Dateability IV: Nominal DV: Ratio IV: Discrete DV: Continuous Are people with curly hair or straight hair more “dateable”

. Example of a study Are people with curly hair or straight hair more “dateable” Directional? (is it predicting who is more dateable? Between Or within? Non- directional Between This is called the “null hypothesis” How would you state no difference between groups? No difference in the dateability of people with straight versus curly hair How would you state yes difference between groups? Yes there is a difference in the dateability of people with straight versus curly hair This is called “rejecting the null hypothesis”

. Example of a study Are people with curly hair or straight hair more “dateable” How would you state no difference between groups? No difference in the dateability of people with straight versus curly hair What if you are wrong What if you are wrong? Type II Error or “miss” Type I Error “false alarm” How would you state yes difference between groups? Yes there is a difference in the height between men and women

Create example of t-test Identify single IV (two levels) Identify DV (must be numeric) Graph should have two bars (one for each mean) Think about how you might Study Type 2: t-test Comparing Two Means? Use a t-test t-test: Curly vs Straight hair

Writing Assignment Worksheet Distributed in Class Designing t-tests

Writing Assignment Please watch this video describing a series of t-tests What is the independent variable? How many different independent and dependent variables can you find?