Introduction to Statistics for the Social Sciences SBS200 - Lecture Section 001, Fall 2017 Room 150 Harvill Building 10:00 - 10:50 Mondays, Wednesdays & Fridays. Welcome http://www.youtube.com/watch?v=oSQJP40PcGI

writing assignment forms notebook and clickers to each lecture Remember bring your writing assignment forms notebook and clickers to each lecture

Three tries Will show up in grades within 24 hours

Lab sessions Labs continue Today Everyone will want to be enrolled in one of the lab sessions Labs continue Today

Project 1 Likert Scale (summated scale) Correlation (scatterplots) Comparing two means (bar graph)

Project 1 - Likert Scale - Correlations - Comparing two means (bar graph) Questions?

Break up group of kids into two groups If you want to know if studying improves test performance in young children Group 1 - studies & tested Break up group of kids into two groups What is the independent variable? 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

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

Placebo (single blind) versus double blind procedure Single blind procedure (example: use of placebo) Double blind procedure What about experimenter bias?

Continuous versus discrete Continuous variable: Variables that can assume any value. There are (in principle) an infinite number of values between any two numbers Discrete variable: Variables that can only assume whole numbers. There are no intermediate values between the whole numbers Duration Amount of sand Number of eggs in a carton Amount of milk in a glass Height Number of cookies on a plate Distance to the moon Grains of sand Number of kids in classroom Number of textbooks required for class

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 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 Hair color Ethnic group GPA Age (Time since birth) Temperature (Kelvin) Yearly salary Breed of dog Gender - male or female Temperature (Fahrenheit) Please note this is a binary variable

On a the top half of a writing assignment form 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 On a the top half of a writing assignment form please generate two examples of categorical data and two examples of numerical data Please note we’ll use the bottom half for something else

What are the four “levels of measurement”? Ratio Absolute zero Most numeric Categories Intrinsic ordering Equal sized intervals Units meaningful Interval Names Categories Intrinsic ordering Ordinal Approaching Numeric Categories Least numeric Names Nominal Weakest

What are the four “levels of measurement”? Categorical data Nominal data - classification, differences in kind, names of categories Ordinal data - order, rankings, differences in degree Numerical data 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”? Categorical data Nominal data - classification, differences in kind, names of categories Ordinal data - order, rankings, differences in degree Numerical data Interval data - measurable differences in amount, equal intervals Ratio data - measurable differences in amount with a “true zero” Age Hair color Telephone number Ethnic group Breed of dog Temperature Yearly salary

Please note : page 29 in text

What are the four “levels of measurement”? Categorical data Nominal data - classification, differences in kind, names of categories Ordinal data - order, rankings, differences in degree Numerical data Interval data - measurable differences in amount, equal intervals Ratio data - measurable differences in amount with a “true zero” Look at your examples of qualitative and quantitative data. Which levels of measurement are they?

Thank you! See you next time!!