Introduction to Statistics for the Social Sciences SBS200 - Lecture Section 001, Spring 2019 Room 150 Harvill Building 9:00 - 9:50 Mondays, Wednesdays & Fridays. http://www.youtube.com/watch?v=oSQJP40PcGI

Even if you have not yet registered your clicker you can still participate The Green Sheets

Lab sessions No Class on Monday No Labs next week Everyone will want to be enrolled in one of the lab sessions No Class on Monday No Labs next week

Schedule of readings Before next exam (February 8) Please read chapters 1 - 5 in OpenStax textbook Please read Appendix D, E & F online On syllabus this is referred to as online readings 1, 2 & 3 Please read Chapters 1, 5, 6 and 13 in Plous Chapter 1: Selective Perception Chapter 5: Plasticity Chapter 6: Effects of Question Wording and Framing Chapter 13: Anchoring and Adjustment

Two parts to any study: independent vs dependent variable Are commercials with animals funnier than commercials without animals? Please rate these commercials (some have animals, some don’t) What are you measuring? What is the dependent variable? The rating of the commercials (from 1 – 10) What is the independent variable? Whether or not there is an animal in the commercial How do your groups differ? Review http://www.youtube.com/watch?v=tKH2oLjQIAA

Quasi versus True Experiments Random assignment: all participants have an equal probability of being assigned to every level of the independent variable Non-random assignment: self selection or subject variables Quasi or True design? Cell phones and driving Sleep and memory Gender and spending Sometimes random assignment is not possible Review

Random sampling vs Random assignment Random assignment of participants into groups: Any subject had an equal chance of getting assigned to either condition (related to quasi versus true experiment) Random sampling of participants into experiment: Each person in the population has an equal chance of being selected to be in the sample Population: The entire group of people about whom a researcher wants to learn Sample: The group of people who actually participate in a research study Review

Within - participant (same as within - subject) & Between - participant (same as between - subject) Within-participant design: each subject participates in every level of independent variable (aka repeated measures) Between-participant design: each subject participates in only one level of independent variable Within or between participant design? Music make plants grow? Animals make funnier commercials? Effect of sleep on memory ability

Practice with types of methodologies If you want to know if studying improves test performance in young children Break up group of kids into two groups by asking if they would like to study What is the independent variable? Group 1 - studies & tested What is the dependent variable? How many levels are there of the IV? Is this a “quasi” or “true” experiment? “Between” or “within” participant design? Group 2 - does not study & tested

Practice with types of methodologies If you want to know if “Ginseng drink” is associated with feelings of satisfaction What is the independent variable? What is the dependent variable? First test group with placebo drink (sugar pill) How many levels are there of the IV? “Between” or “within” participant design? Then test same group with “Ginseng drink”

Placebo

Placebo (single blind) versus double blind procedure What about experimenter bias?

Handedness - right handed or left handed Categorical versus Numerical data Categorical data (also called qualitative data) - a set of observations where any single observation is a word or a number that represents a class or category Numerical data (also called quantitative data) - a set of observations where any single observation is a number that represents an amount or count Handedness - right handed or left handed Family size Temperature (Fahrenheit) Hair color Ethnic group GPA Age Yearly salary Breed of dog Gender - male or female

Characteristics of a number “levels of measurement” Ratio Absolute zero Most numeric Categories Intrinsic ordering Equal sized intervals Units meaningful Interval Names Categories Intrinsic ordering Approaching Numeric Ordinal Categories Least numeric Names Nominal Weakest

What are the four “levels of measurement”? Qualitative Nominal data - classification, differences in kind, names of categories Ordinal data - order, rankings, differences in degree

What are the four “levels of measurement”? Qualitative Nominal data - classification, differences in kind, names of categories Ordinal data - order, rankings, differences in degree Quantitative Interval data - measurable differences in amount, equal intervals Ratio data - measurable differences in amount with a “true zero”

What are the four “levels of measurement”? Qualitative Nominal data - classification, differences in kind, names of categories Ordinal data - order, rankings, differences in degree Quantitative Interval data - measurable differences in amount, equal intervals Ratio data - measurable differences in amount with a “true zero” Gender - male or female Family size Jersey number Place in a foot race (1st, 2nd, 3rd, etc) Handedness - right handed or left handed

What are the four “levels of measurement”? Qualitative Nominal data - classification, differences in kind, names of categories Ordinal data - order, rankings, differences in degree Quantitative Interval data - measurable differences in amount, equal intervals Ratio data - measurable differences in amount with a “true zero” Age (Time passed - duration) Temperature (Kelvin Scale) Ethnic group Telephone number Temperature (Fahrenheit) Hair color Breed of dog Yearly salary

Writing Assignment – Pop Quiz Ari conducted a watermelon seed spitting experiment. She wanted to know if people can spit farther if they get a running start. She tested 100 people. She randomly assigned them into one of two groups. One group stood still on the starting line and spit their watermelon seeds as far as they could. The second group was allowed to run up to the starting line before they spit their watermelon seeds. She measured how far each person spit their watermelon seeds. Please answer the following questions 1. What is the independent variable? 2. The independent variable: Is it continuous or discrete? 3. The independent variable: Is it nominal, ordinal, interval or ratio? 4. What is the dependent variable? 5. The dependent variable: Is it continuous or discrete? 6. The dependent variable: Is it nominal, ordinal, interval or ratio? 7. Is this a quasi or true experiment? 8. Is this a within or between participant design 9. Is this a single blind, double blind or not at all blind experiment? 10. Be sure to put your name on this page

Writing Assignment – Pop Quiz Ari conducted a watermelon seed spitting experiment. She wanted to know if people can spit farther if they get a running start. She tested 100 people. She randomly assigned them into one of two groups. One group stood still on the starting line and spit their watermelon seeds as far as they could. The second group was allowed to run up to the starting line before they spit their watermelon seeds. She measured how far each person spit their watermelon seeds. Running versus standing still Please answer the following questions 1. What is the independent variable? 2. The independent variable: Is it continuous or discrete? 3. The independent variable: Is it nominal, ordinal, interval or ratio? 4. What is the dependent variable? 5. The dependent variable: Is it continuous or discrete? 6. The dependent variable: Is it nominal, ordinal, interval or ratio? 7. Is this a quasi or true experiment? 8. Is this a within or between participant design 9. Is this a single blind, double blind or not at all blind experiment? 10. Be sure to put your name on this page Discrete Distance that the seed was spit Nominal Continuous True Experiment Ratio Between Not at all

Thank you! See you next time!!