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MGMT 276: Statistical Inference in Management. Welcome. http://www.youtube.com/watch?v=tKH2oLjQIAA. Remember bring your writing assignment forms notebook and clickers to each lecture. _____ Class ID Name: ___________________ Date: __________.
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MGMT 276: Statistical Inference in Management. Welcome http://www.youtube.com/watch?v=tKH2oLjQIAA
Remember bring your writing assignment forms notebook and clickers to each lecture _____ Class ID Name: ___________________ Date: __________ MGMT276: Statistical Inference in ManagementWriting Assignment Number__________________________________________________________ ______________________________________________________ ______________________________________________________ ______________________________________________________ ______________________________________________________ ______________________________________________________
Please click in • Homework due next class - (January 27th) • My last name starts with a • letter somewhere between A. A – D B. E – L C. M – R D. S – Z On class website: please print and complete homework worksheet #2 Please double check – Allcell phones other electronic devices are turned off and stowed away Turn your clicker on
Homework review You are looking to see if “class standing” affects the “level of sales”. Class standing Independent variable (IV):______________ Number of levels of IV: ________________ (how many means?) Quasi or True experiment:______________ Dependent variable: __________________ Between or within participant design: ______________ In this study, what is the operational definition of “class standing”? In this study, what is the operational definition of “level of sales”? 4 Quasi Level of sales Between Classification based on units earned Number of bags of peanuts sold
Homework review You are looking to see whether “type of program” has an effect on “body transformation”. Please identify the following variables: Independent variable (IV):______________ Number of levels of IV: _______________ (how many means?) Quasi or True experiment:______________ Dependent variable: __________________ Between or within participant design: ______________ What is the operational definition of “type of program”? What is the operational definition of “body transformation”? Type of program 2 True Body transformation Between Type of program = type of diet (regular versus programmatic diet) Body transformation = number of pounds lost
Homework review You are looking to see which driving choice is most efficient. So you ask each driver to drive each of the three routes and time themselves on how long it takes. Please identify the following variables: Independent variable (IV):______________ (how many means) Number of levels of IV: ________________ Dependent variable: __________________ Between or within participant design: ______________ What is the operational definition of “driving efficiency”? What is the operational definition of “driving choice”? Type of route 3 driving efficiency Within Driving efficiency = travel time (measured in minutes) Driving choice = route taken
Use this as your study guide By the end of lecture today1/25/11 Single blind (placebo) procedure Double blind procedure Random Assignment vs Random Sampling Population vs Sample Continuous versus discrete Categorical versus Numerical data Levels of Measurement Descriptive vs inferential statistics Time series versus cross-sectional Simple versus systematic random sampling Sample frame and randomization Stratified sampling, cluster sampling, judgment sampling Snowball sampling, convenience sampling Questionnaire design and evaluation
Schedule of readings • Before next exam: • Please read chapters 1 - 4 in Lind 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
Group 1 - studies & tested If you want to know if studying improves test performance in young children 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
First test group with placebo drink (sugar pill) If you want to know if “Ginseng drink” is associated with feelings of satisfaction 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?
So far, Measurement: observable actions Theoretical constructs: concepts (like “humor” or “satisfaction”) Operational definitions Validity and reliability Independent and dependent variable Random assignment and Random sampling Within-participant and between-participant design Single blind (placebo) and double blind procedures
Let’s try one A study explored whether eating carrots really improves vision. Half of the subjects ate a package of carrots everyday for 3 months while the other group did not. Then, they tested the vision for all of the subjects. The independent variable in this study was a. the performance of the subjects on the vision exam b. the subjects who ate the carrots c. whether or not the subjects ate the carrots d. whether or not the subjects had their vision tested Turn your clicker on
Let’s try one A study explored whether eating carrots really improves vision. Half of the subjects ate a package of carrots everyday for 3 months while the other group did not. Then, they tested the vision for all of the subjects. The dependent variable in this study was a. the performance of the subjects on the vision exam b. the subjects who ate the carrots c. whether or not the subjects ate the carrots d. whether or not the subjects had their vision tested Turn your clicker on
Let’s try one A study explored whether eating carrots really improves vision. Half of the subjects ate a package of carrots everyday for 3 months while the other group did not. Then, they tested the vision for all of the subjects. This experiment was a a. within participant experiment b. between participant experiment c. mixed participant experiment d. non-participant experiment Turn your clicker on
Let’s try one When Martiza was preparing her experiment, she knew it was important that the participants not know which condition they were in, to avoid bias from the subjects. This is called a _____ study. She also was careful that the experimenters who were interacting with the participants did not know which condition those participants were in. This is called a ____ study. a. between participant; within participant b. within participant; between participant c. double blind design; single blind d. single blind; double blind design Turn your clicker on
Let’s try one A measurement that has high validity is one that a. measures what it intends to measure b. will give you similar results with each replication c. will compare the performance of the same subjects in each experimental condition d. will compare the performance of different subjects in each experimental condition Turn your clicker on
Let’s try one A study explored whether conservatives or liberals had more bumper stickers on their cars. The researchers ask 100 activists to complete a conservative/liberal values test, then used those results to categorize them as liberal or conservative. Then they identified the 30 most conservative activists and the 30 most liberal activists and measured how many bumper stickers each activist had on their car. The independent variable in this study was a. the performance of the activists b. the number of bumper stickers found on their car c. political status of participant (liberal versus conservative) as determined by their performance on the liberal/conservative test d. whether or not the subjects had bumper stickers on their car Turn your clicker on
Let’s try one A study explored whether conservatives or liberals had more bumper stickers on their cars. The researchers asked 100 activists to complete a conservative/liberal values test, then used those results to categorize them as liberal or conservative. Then they identified the 30 most conservative activists and the 30 most liberal activists and measured how many bumper stickers each activist had on their car. The dependent variable in this study was a. the performance of the activists b. the number of bumper stickers found on their car c. political status of participant (liberal versus conservative) as determined by their performance on the liberal/conservative test d. whether or not the subjects had bumper stickers on their car Turn your clicker on
Let’s try one A study explored whether conservatives or liberals had more bumper stickers on their cars. The researchers 100 activists to complete a conservative/liberal values test, then used those results to categorize them as liberal or conservative. Then they identified the 30 most conservative activists and the 30 most liberal activists and measured how many bumper stickers each activist had on their car. This study was a a. within participant experiment b. between participant experiment c. mixed participant experiment d. non-participant experiment Turn your clicker on
Let’s try one A study explored whether conservatives or liberals had more bumper stickers on their cars. They had 100 activists complete liberal/conservative test. Then, they split the 100 activists into 2 groups (conservatives and liberals). They then measured how many bumper stickers each activist had on their car. This study used a a. true experimental design b. quasi-experiment design c. correlational design d. mixed design Turn your clicker on
Random sampling vs Random assignment Random assignment of participants into groups: Any subject had an equal chance of getting assigned to either condition 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
How tall is the average U of A student? Population: University students – 37,000 students Sample: Subset of students – 100 students Biases?
Duration 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 Distance Number of kids Height Number of eggs in a carton 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
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 Yearly salary Breed of dog Gender - male or female Temperature Please note this is a binary variable
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”? 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”
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!!