Lecturer’s desk Physics- atmospheric Sciences (PAS) - Room 201 s c r e e n Row A Row B Row C Row D Row E Row F Row G Row H Row A Row B Row C Row D Row E Row F Row G Row H table Row A Row B Row C Row D Row E Row F Row G Row H Row J Row K Row L Row M Row N Row P Row J Row K Row L Row M Row N Row P Row Q table

MGMT 276: Statistical Inference in Management Fall 2015

We’ll be starting this next week

By the end of lecture today 9/10/15 Use this as your study guide Field observation/naturalistic research Peer review and the iterative approach in design Questionnaire design and evaluation Dot Plots Frequency Distributions

More information on how to register clicker soon A note on doodling Remember bring your writing assignment forms notebook and clickers to each lecture

Optional Homework due- (Tuesday, September 15 th ) Students are invited to rework Homework Assignment 2 & 3 based on feedback provided in class We will provide feedback today on this assignment

Just for Fun Assignments Go to D2L - Click on “Content” Click on “Interactive Online Just-for-fun Assignments” Complete Assignments 1 – 7 Please note: These are not worth any class points and are different from the required homeworks

Schedule of readings Before next exam: Please read Chapters in OpenStax Supplemental reading (Appendix D) Supplemental reading (Appendix E) Supplemental reading (Appendix F) 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

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 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 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 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 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

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

Preview of Questionnaire Homework There are five parts: Statement of Objectives Questionnaire itself (which is the operational definitions of the objectives) Data collection and creation of database Creation of graphs representing results Generate a formal memorandum describing results Must be complete and must be stapled

Iterative design process Peer review is an important skill in nearly all areas of business and science. Please strive to provide productive, useful and kind feedback as you complete your peer review

Iterative design process Peer review is an important skill in nearly all areas of business and science. Please strive to provide productive, useful and kind feedback as you complete your peer review If you do not have a hard copy of your formal memorandum you may not participate. There is alternative worksheet, please ask for one. You have 10 minutes You have 10 minutes

Preview of Questionnaire Homework There are five parts: Statement of Objectives Questionnaire itself (which is the operational definitions of the objectives) Data collection and creation of database Creation of graphs representing results Generate a formal memorandum describing results Hand in the peer review with the questionnaire *Hand them in together*

You’ve gathered your data…what’s the best way to display it??

Describing Data Visually Lists of numbers too hard to see patterns Organizing numbers helps Graphical representation even more clear This is a dot plot

Describing Data Visually Measuring the “frequency of occurrence” Then figure “frequency of occurrence” for the bins We’ve got to put these data into groups (“bins”)

Frequency distributions Frequency distributions an organized list of observations and their frequency of occurrence How many kids are in your family? What is the most common family size?

Another example: How many kids in your family? Number of kids in family

Frequency distributions Crucial guidelines for constructing frequency distributions: 1. Classes should be mutually exclusive: Each observation should be represented only once (no overlap between classes) 2. Set of classes should be exhaustive: Should include all possible data values (no data points should fall outside range) Wrong Correct Correct 0 - under under under 15 How many kids are in your family? What is the most common family size? Number of kids in family Wrong Correct No place for our family of 14!

Frequency distributions Crucial guidelines for constructing frequency distributions: 3. All classes should have equal intervals (even if the frequency for that class is zero) Wrong Correct Correct 0 - under under under 15 How many kids are in your family? What is the most common family size? Number of kids in family missing space for families of 5, 6, or 7

4. Selecting number of classes is subjective Generally will often work How about 6 classes? (“bins”) How about 8 classes? (“bins”) How about 16 classes? (“bins”)

5. Class width should be round (easy) numbers 6. Try to avoid open ended classes For example 10 and above Greater than 100 Less than 50 Clear & Easy Round numbers: 5, 10, 15, 20 etc or 3, 6, 9, 12 etc Lower boundary can be multiple of interval size Remember: This is all about helping readers understand quickly and clearly.

Let’s do one Scores on an exam If less than 10 groups, “ungrouped” is fine If more than 10 groups, “grouped” might be better How to figure how many values = 47 Step 1: List scores Step 2: List scores in order Step 3: Decide whether grouped or ungrouped Step 4: Generate number and size of intervals (or size of bins) Largest number - smallest number + 1 Sample size (n) 10 – – – – – – 1,024 Number of classes If we have 6 bins – we’d have intervals of 8 Whaddya think? Would intervals of 5 be easier to read? Let’s just try it and see which we prefer…

Scores on an exam Scores on an exam Score Frequency – Scores on an exam Score Frequency bins Interval of 5 6 bins Interval of 8 Let’s just try it and see which we prefer… Remember: This is all about helping readers understand quickly and clearly. Scores on an exam Score Frequency –

Scores on an exam Scores on an exam Score Frequency – Let’s make a frequency histogram using 10 bins and bin width of 5!!

Scores on an exam Score Frequency – Step 6: Complete the Frequency Table Scores on an exam Cumulative Frequency Relative Frequency Relative Cumulative Frequency bins Interval of 8 Just adding up the frequency data from the smallest to largest numbers Just dividing each frequency by total number to get a ratio (like a percent) Please note: 1 /28 = / 28 = /28 =.1429 Just adding up the relative frequency data from the smallest to largest numbers Please note: Also just dividing cumulative frequency by total number 1/28 = /28 = /28 =.1786

Scores on an exam Score Frequency – Cumulative Frequency Data Scores on an exam Cumulative Frequency Relative Frequency Cumulative Rel. Freq Cumulative Frequency Histogram Where are we?

Data based poll on 9/15 Who is your favorite candidate Candidate Frequency Hillary Clinton45 Bernie Sanders23 Joe Biden17 Jim Webb 1 Other/Undecided 14 Simple Frequency Table – Qualitative Data We asked 100 Democrats “Who is your favorite candidate?” Relative Frequency Just divide each frequency by total number Please note: 45 /100 = /100 = /100 = /100 =.0100 Percent 45% 23% 17% 1% 14% If 22 million Democrats voted today how many would vote for each candidate? Number expected to vote 9,900,000 5,060,000 3,740, ,000 3,080,000 Just multiply each relative frequency by 100 Please note:.4500 x 100 = 45%.2300 x 100 = 23%.1700 x 100 = 17%.0100 x 100 = 1% Just multiply each relative frequency by 22 million Please note:.4500 x 22m = 9,900k.2300 x 22m = 35,060k.1700 x 22m = 23,740k.0100 x 22m= 220k

Step 4: Decide 10 for # bins (classes) 5 for bin width (interval size) Scores on an exam Step 1: List scores Step 2: List scores in order Step 3: Decide grouped Scores on an exam Score Frequency – Step 5: Generate frequency histogram Score on exam

Scores on an exam Scores on an exam Score Frequency – Score on exam Generate frequency polygon Plot midpoint of histogram intervals Connect the midpoints

Scores on an exam Scores on an exam Score 95 – – Score on exam Frequency ogive is used for cumulative data Generate frequency ogive (“oh-jive”) Cumulative Frequency Connect the midpoints Plot midpoint of histogram intervals

Pareto Chart: Categories are displayed in descending order of frequency

Stacked Bar Chart: Bar Height is the sum of several subtotals

Simple Line Charts: Often used for time series data (continuous data) (the space between data points implies a continuous flow) Note: Can use a two-scale chart with caution Note: Fewer grid lines can be more effective Note: For multiple variables lines can be better than bar graph

Pie Charts: General idea of data that must sum to a total (these are problematic and overly used – use with much caution) Bar Charts can often be more effective Exploded 3-D pie charts look cool but a simple 2-D chart may be more clear Exploded 3-D pie charts look cool but a simple 2-D chart may be more clear