Visualizations, Linear Regression and Correlation

Comic of the Day

Tip: Beware the temptation of the procrastination side

Announcements and Deadlines

Labs 6, 7, 8 and 10 due Thu Apr 16
Excel Final Exam on Thu Apr 16
Chapter 6-8 and Visualizations/Chapter 12 assignments (Moodle) due Thu Apr 23

Theory Exam (Chapter 6-8) is combined with Chapter 12 exam and will be on Thu Apr 23

This Week

1. Visualizations

To supplement the lecture notes, read the excerpts from Tufte's "Visual Display of Quantitative Information", the article "Charting Safety Performance" from the American Society of Safety Professionals, and "Leading Indicators for Workplace Health and Safety" from Work Safe Alberta.

2. Linear Regression

Tip: Some relationships are linear, some can't be explained...

Guess the regression line!
https://www.geogebra.org/m/JsFmFEg6

3. Correlation

Spurious Correlations
Have too much time on your hands?  Try this!
http://guessthecorrelation.com/
Notes on Moodle

For More Information

Regression

https://www.khanacademy.org/math/probability/regression/regression-correlation/e/plotting_the_line_of_best_fit

https://www.khanacademy.org/math/probability/regression/regression-correlation/e/linear-models-of-bivariate-data

https://www.khanacademy.org/math/probability/regression/regression-correlation/v/r-squared-or-coefficient-of-determination

Correlation
https://www.khanacademy.org/math/probability/regression/regression-correlation/v/correlation-and-causality
https://www.khanacademy.org/math/probability/regression/regression-correlation/e/linear-models-of-bivariate-data

Next Week - Exams

Look at Exam Prep Sheet and other study resources

Sampling Distributions, Central Limit Theorem and Confidence Intervals

Comic of the Day

Tip: The things themselves are all right, so who cares?

Announcements and Deadlines

Labs 6, 7, 8 and 10 due Thu Apr 16
Excel Final Exam on Thu Apr 16
Chapter 6-8 assignment (Moodle) due Thu Apr 23

Theory Exam (Chapter 6-8) is combined with Chapter 12 exam and will be on Thu Apr 23

This Week

1. Sampling Distributions and Central Limit Theorem

Central Limit Theorem Simulator

http://onlinestatbook.com/stat_sim/sampling_dist/

Set n=25 and run the simulator several hundred thousand times. 

For any population distribution (normal, uniform, skewed, custom), the distribution of the sample mean, x̄, is normally distributed with the following properties:

the mean of the sample means approaches the population mean

the standard deviation of the sample means is less than the population standard deviation (it actually follows the formula below)

Lab 8 - Sampling Distributions
Lab 8 shows how a sample mean, x̄ (n=16 or 100) is usually close to a population mean, µ (N=10,000), and gets closer as n increases.  You will use a VLOOKUP function to randomly sample from your payroll data.

3. Confidence Intervals

"A Mainstreet Technologies poll ... suggests Albertans are highly resistant to any tax hikes. Only 15 per cent of survey respondents say they’d favour increased taxes. Spending cuts are the preferred solution of 43 per cent."

"...automated phone survey of 3,184 Albertans."

"The Mainstreet Technologies survey is considered accurate within plus or minus 1.7 percentage points, 19 times out of 20."

http://calgaryherald.com/news/politics/alberta-sales-tax-the-most-detested-budget-solution-poll-says

Confidence Interval for Population Proportion, p

https://www.geogebra.org/m/kh7ndb2N

Confidence Interval for Population Mean, µ (σ known)

https://www.geogebra.org/m/NuypFzw9

Confidence Interval for Population Mean (σ unknown)

https://www.geogebra.org/m/HdXrD6Tw

For More Information

Sampling distribution
https://www.khanacademy.org/math/probability/statistics-inferential/sampling_distribution/v/sampling-distribution-of-the-sample-mean
https://www.khanacademy.org/math/probability/statistics-inferential/sampling_distribution/v/sampling-distribution-of-the-sample-mean-2
https://www.khanacademy.org/math/probability/statistics-inferential/sampling_distribution/v/standard-error-of-the-mean
https://www.khanacademy.org/math/probability/statistics-inferential/sampling_distribution/v/sampling-distribution-example-problem

Confidence Intervals (videos go beyond the content of this course)

https://www.khanacademy.org/math/probability/statistics-inferential/confidence-intervals/v/confidence-interval-1
https://www.khanacademy.org/math/probability/statistics-inferential/confidence-intervals/v/confidence-interval-example

Confidence Intervals (small sample size)

https://www.khanacademy.org/math/probability/statistics-inferential/confidence-intervals/v/small-sample-size-confidence-intervals

Next Week - Linear Equations and Graphs, Lab 10 - Linear Regression

Pre-read notes on Moodle

Lab 7 - Normal Distributions

Comic of the Day

Tip: We might all be a little out of practice, so go easy on us?

Announcements and Deadlines

Production Assignment 2 assessments and peer/self evaluation due Sun Mar 22

Chapter 6-8 assignment (Moodle) due Mon Mar 30

Theory Exam (Chapter 6-8) postponed until further notice

This Week - Lab 7 - Normal Distribution

Lab instruction video on Moodle
Mobius questions

For More Information

Normal distribution

http://patrickjmt.com/the-normal-distribution-and-the-68-95-99-7-rule/
https://www.khanacademy.org/math/probability/statistics-inferential/normal_distribution/e/z_scores_1

Next Week - Lab 8 - Sampling Distributions

Lab instruction video and Mobius questions are already posted

Lab 6 - Probability

Comic of the Day

Tip: Watch your syntax when using the =FRIENDIF() function

Applications of Visualizations

Dashboard

https://gisanddata.maps.arcgis.com/apps/opsdashboard/index.html#/bda7594740fd40299423467b48e9ecf6

Understand statistics, don't BE a statistic

https://www.nytimes.com/2020/03/11/science/coronavirus-curve-mitigation-infection.html

Prevention

https://www.albertahealthservices.ca/

To help protect you and your family against all respiratory illnesses, including flu and COVID-19, you should:

• Wash your hands often and well
• Avoid touching your face, nose, or mouth with unwashed hands.
• Avoid close contact with people who are sick
• Clean and disinfect surfaces that are frequently touched
• Stay at home and away from others if you are feeling ill
• Contact your primary health provider or Health Link 811 if you have questions or concerns about your health
• When sick, cover your cough and sneezes and then wash your hands

Announcements and Deadlines

Production Assignment 2 assessments and peer/self evaluation due Sun Mar 15

Chapter 6-8 assignment (Moodle) due Mon Mar 30

Theory Exam (Chapter 6-8) in class Mon Mar 30

Drop-in tutorials will run every Tue 12-12:50 in CAT286 (computer lab)

Today - Lab 6 - Probability

See videos on Moodle
Activity 1 is related to injury rates in your individual data sets
In Activity 2 you will create a binomial probability distribution related to injury rates, and then also create a model for workplace injuries using random number generation in Excel.  Excel's built-in Binomial Distribution function with the following syntax:
BINOM.DIST(x,n,p,false)

Next Lecture - 7.1-7.3 Sampling Distributions and Central Limit Theorem
Pre-read 7.1-7.3 in the textbook
Watch this 10:41 primer video on the Central Limit Theorem
https://www.khanacademy.org/math/ap-statistics/sampling-distribution-ap/sampling-distribution-mean/v/sampling-distribution-of-the-sample-mean

6.2 Applications of Normal Distributions

Comic of the Day

Tip: Always make the diagram match one on our z table

Unit 2 Exam (out of 25 marks)

µ=64.3%
σ=20.5%
median=66%
60% within µ±1σ

Unit 1 Exam (was changed to out of 25 marks instead of 30)

µ=58.1% 69.7%

σ=18.4% 22.1%

median=60% 72%

70.0% within µ±1σ

For students who scored 100% on Mobius chapter 1-4 assignments:
µ=75.8% on Unit 1&2 Exams

For students who scored <100% on Mobius chapter 1-4 assignments:
µ=51.8% on Unit 1&2 Exams

Announcements and Deadlines

Production Assignment 2 assessments and peer/self evaluation due Sun Mar 15

Chapter 6-8 assignment (Moodle) due Mon Mar 30

Theory Exam (Chapter 6-8) in class Mon Mar 30

Drop-in tutorials will run every Tue 12-12:50 in CAT286 (computer lab)

Today - 6.2 Applications of Normal Distributions

Notes on Moodle

z-score calculator

https://www.geogebra.org/m/zeF3hkXf

For More Information

Normal distribution

http://patrickjmt.com/the-normal-distribution-and-the-68-95-99-7-rule/
https://www.khanacademy.org/math/probability/statistics-inferential/normal_distribution/e/z_scores_1

Next Lecture - Lab 6 - Probability
Watch the video tutorial and try it on your own

6.1 Standard Normal Distribution

Comic of the Day

Tip: It's not that scary if you practice

Explanation of Grading for Production Assignment 1

Submission Grade (ave 29.9/40) - instructor graded

Individual Contribution (ave 8.9/10) - based on the Peer and Self Evaluation ratings, comments, and my observations

Assessment Grade (ave 8.0*/10) - based on how close you graded the group versus how I graded the group, and also on the quality of your comments (specific and insightful)

* students who did not assess other groups were assigned a grade of zero and were not included in this average

Announcements and Deadlines

Production Assignment 2 assessments and peer/self evaluation due Sun Mar 15

Chapter 6-8 assignment (Moodle) due Mon Mar 30

Theory Exam (Chapter 6-8) in class Mon Mar 30

Drop-in tutorials will run every Tue 12-12:50 in CAT286 (computer lab)

Today - 6.1 Standard Normal Distribution

Notes on Moodle

z-score calculator

https://www.geogebra.org/m/zeF3hkXf

For More Information

Normal distribution

http://patrickjmt.com/the-normal-distribution-and-the-68-95-99-7-rule/

https://www.khanacademy.org/math/probability/statistics-inferential/normal_distribution/e/z_scores_1

Next Lecture - 6.2 Applications of Normal Distributions

Pre-read notes on Moodle

Feedback from PA1

Feedback from PA1
- read the rubric carefully and make sure you are meeting all the criteria (e.g. whether it's a table or a chart, what the rows/columns should be, how much/little information to include, what Excel functions/features should be enabled like a Filter)
- who is your intended audience?  An email to a front line supervisor should be short and to the point.  For PA2, a briefing report for senior management should have a little more substance but be careful not to include redundant sentences just to "flower things up"
- the analysis has to be correct!  In PA1 you needed to correctly count the number of employees in each category (never trained, expired, will expire and by each training type).  For PA2 you will need to use correct data for all of your charts.

Suggestions for PA2
- double-check that you haven't missed any data or counted anything twice
- each chart should have a clear message and a reason why you have included it
- three mandatory charts (raw data, histogram, ogive)
- two or more additional charts (e.g. pie, stacked column, boxplot) that focus on overexposures, other contributing factors or changes over time
- do not include your names anywhere.  If you need a name you are Saif T. Guy.  In the workplace you will have to be careful not to violate employee privacy and accidentally include their name on an injury report!

Remember:
Under no circumstances should you be sharing your files (including the raw data files) with other groups, and under no circumstances should you open files from other groups.