Dealing with Discrete Count Variables

​​​​​​​Once you learn the ins and outs of linear models, it can seem that you’re ready to tackle any dependent variable.

But…

Not all numerical dependent variables are created equal! Some are discrete, not continuous:

-- Number of surviving offspring

​​​​​-- Number of crimes committed in an area

-- Number of days in the hospital

If you apply linear regression, which is designed for continuous dependent variables, to discrete dependent variables, you’re going to run into some BIG issues…

It will seem like you’ve performed the right analysis, but your results will be inconsistent and biased.  Fortunately, there’s a solution…

Introducing…

Analyzing Count Data:

Poisson, Negative Binomial, and Other Essential Models

A 6-Module Online, Live Interactive Workshop with Jeff Meyer

Workshop starts Thursday, April 12th, 2018.

I’m Jeff Meyer, workshop instructor

My goal is that by the end of the workshop, you’ll know how to spot when you need a count model and how to choose the most appropriate one, implement it, and understand the results. You’ll learn six different types of count models (plus all their varieties) and how to select the one that will work best for your specific data set.

In this six-module live, online workshop, we’ll cover:

-- What counts are and why they don’t work well in linear models

-- When a model is appropriate and how to evaluate a model

-- Working with Offset/Exposure Variables

-- Understanding Incidence Rate Ratios and the log link function

-- Steps to Running a Poisson Model

-- Interpreting Coefficients, Marginal Effects, and Interactions

-- Overdispersion & Negative Binomial Models

-- Model Fit, Assumptions, and Influence

-- Zero Truncated, Hurdle, Zero Inflated Poisson and Negative Binomial Models

"Mr. Meyer works very hard to pass along as much information as he can."

- Collin Stewart, previous workshop participant
Who is this workshop for?

This workshop is suitable for graduate students and research professionals. It’s for you if you:

-- Have tried to do a Poisson or negative binomial regression before, but found it confusing or difficult
--​​ ​​​Have used linear regression or ANOVA and want to take your statistical skills to the next step

-- Know you will need to implement a count model soon

It’s not for you if you:

-- ​​​​​​​Are a statistics beginner and have never done a linear regression
​​​​​​​​​​​​​-- Have an advanced degree in statistics and want theoretical knowledge of count models

How does it work?

This course is a 6-module live, interactive online workshop from Thursday, April 12th, 2018.

All sessions are conducted online via live webinar. You can log in via phone or Internet. You’ll see the instructor’s screen to view the presentation… all from your own home or office.

During each webinar session, the instructor will cover core concepts, and will leave plenty of time to ask your own questions.

Have more questions? No problem!

In addition to the six module sessions, you’ll also meet with your instructor for six additional Q&A sessions where you can get additional assistance on workshop concepts, deepen your knowledge, and clarify any questions.

All 6 Workshop Modules and 6 Q&A Sessions Are Recorded for Your Convenience.

As a participant in the Analyzing Count Data workshop, you’ll have access to a participant-only website, your workshop “hub.” That’s where you’ll access all workshop resources and material, including:

-- Real research data sets in SPSS, SAS,  Stata, and csv formats.

-- Syntax and demonstration videos to conduct all the workshop examples in SPSS, R, SAS, and Stata.

-- Video screen capture recordings of each workshop session. Made available within 48 hours after each session so you can review the material at your convenience. If you miss any of the live sessions, you can still participate on your own schedule.

-- Exercises. (yes, HOMEWORK!) You really need to practice this stuff and get your hands dirty, so we’re giving you the data to try it on your own. But don’t worry–you won’t be on your own stymied by some coding error that won’t work. You’ll get the code to do the exercises and the answers in case you get stuck.

-- A forum  to submit written questions between sessions. Got a question as you’re reviewing the video recording or your notes? Just submit a question in the workshop forum. Jeff will answer it there if he can, or if it’s something she needs to show you, he’ll answer it in the next Q&A session.

-- Video recordings of all Q&A sessions to review at your convenience. You can even submit questions for the Q&A sessions ahead of time, and Jeff will answer them in the next session and you can watch at your convenience.

-- A list of helpful resources and suggestions for further reading. There’s no required textbook, but there are some good resources that we recommend to support your learning.

-- Bonus videos. We’ve included a few videos from some webinars on relevant topics to help your understanding. Included are:
> A Review of Logarithms for the Data Analyst
> What Happened to R squared?: Assessing Model Fit for Logistic, Multilevel and Other Models that Use Maximum Likelihood
> Binary, Ordinal, and Multinomial Logistic Regression for Categorical Outcomes
> Zero Inflated Models
> Working with Truncated and Censored Data

You’ll have access to this site and all the related materials and resources for ONE FULL YEAR. That means you can re-watch sessions and ask additional questions again during that 12-month period.

Often, our participants report they understand the material at a deeper level on a second or third pass. You’ll learn more every time, so take advantage of it!

"Having Jeff able to respond to queries on the spot – via the question box – was a fantastic resource. For off-topic questions, which he obviously didn’t have time to address within the lecture, he then separately uploaded ‘answers’ onto the course website. That real-time interaction and feedback was truly invaluable. It honestly felt like we were in a physical classroom, which is the biggest compliment I can give."

- Ryan J. Kee, Queen’s University Belfast, previous workshop participant
What's Covered?

Module 1: Understanding Count Models

We’ll start with an understanding of what counts are and why they don’t work well in linear models. We’ll talk in detail about why a count model is necessary and what a log link means.

Then we’ll go through a brief overview of the most important concepts and steps so you have a big-picture understanding. This lays a strong foundation for the rest of the workshop.

We’ll cover:

-- Discrete vs Continuous Variables
-- The Variety of Count Data
-- Why OLS Linear Regression Doesn’t Work with Count Data
-- Modeling Assumptions for Count Data
-- Modeling Process
​​​​​​​-- Offset/Exposure Variable
​​​​​​​-- Incidence Rate Ratios

Module 2: The Poisson Model

Now that you’ve had an overview, we’ll dig deep into the simplest count model: the Poisson. We’ll explore the issues, terminology, and modeling that apply to all count models within the context of this simplest of models.

Covered:

-- Important Terminology
​​​​​​​-- Poisson Model Assumptions
​​​​​​​-- Poisson Distribution
​​​​​​​-- Analyzing Data and Model Fit
​​​​​​​-- Interpreting the Results
​​​​​​​-- Marginal Effects
​​​​​​​-- Interactions

Module 3: The Negative Binomial Model

Now that you understand the Poisson model, we expand on it. Unfortunately, the Poisson model often doesn’t fit real data. In this module we introduce the powerhouse of count models: the negative binomial.

Covered:

-- Overdispersion​​​​​​​
​​​​-- Negative Binomial Distribution
​​​​​​​-- Important Terminology
​​​​​​​-- When to use Negative Binomial Models
​​​​​​​-- Running Models
​​​​​​​-- Model Fit
​​​​​​​-- Negative Binomial Model Assumptions

Module 4: Model Diagnostics and Truncated Models

Now that we’ve run a model, we need to make sure that it fits the data. In this module you learn how to do that in Poisson and negative binomial models and learn a new type of count model that will account for a common failure of model fit--a complete lack of zeros in the data.

Covered:

-- Predicted Values and Residuals: comparison of models
​​​​​​​-- Influential Observations: Cook’s distance
​​​​​​​-- Residuals versus Predicted Values
​​​​​​​-- Residuals versus Predictors
​​​​​​​-- Zero Truncated Models

Module 5: Hurdle and Zero-inflated Models

Lots and lots of zeros in the data. In this module we’ll explore in detail two ways of approaching and dealing with this common situation (think of variables like number of arrests or accidents--most people don’t have any).

Covered:
​​​​​
-- Hurdle Model

​​​​​​​-- Zero Inflated Poisson Model​​​​​​​
​​​​​​​-- Zero Inflated Negative Binomial Model

Module 6: Extension and Review

Now that you understand, in detail, when and how to implement a variety of count models, we’ll do two things.

First, we’ll introduce some lesser-known, but valuable alternative models that are sometimes exactly what you need.

Then we’ll take a data set and go through a model-building example, so you can see, start-to-finish an example of the order in which to do steps, the information to consider, and which output to interpret.

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The Details:

There are 6 Workshop Webinar Sessions.

The workshop sessions are approximately 2 hours long, including time for questions.

The schedule is as follows:

Workshop orientation (Optional) - Wednesday, April 11, at 12 Noon EDT

Live Workshop Dates:

Module 1 – Thursday, April 12 at 12 Noon EDT

Module 2 – Thursday, April 19 at 12 Noon EDT

Module 3 – Thursday, April 26 at 12 Noon EDT

Module 4 – Thursday, May 3rd at 12 Noon EDT

Module 5 – Thursday, May 17th at 12 Noon EDT

Module 6 – Thursday, May 24th at 12 Noon EDT

We will also meet for six, 60-minute Q&A sessions throughout this time. We will meet on the following dates:

Q&A 1 – Wednesday, April 18 at 12 Noon EDT

Q&A 2 – Wednesday, April 25 at 12 Noon EDT

Q&A 3 – Wednesday, May 2 at 12 Noon EDT

Q&A 4 – Wednesday, May 16 at 12 Noon EDT

Q&A 5 – Wednesday, May 23 at 12 Noon EDT

Q&A 6 – Wednesday, May 30 at 12 Noon EDT

Remember, everything is recorded and available for you to watch at your convenience, should you be unable to attend a live session.

Also, you have access to all the class materials for a full 12 months from your enrollment date.

Enrollment for this workshop is closed.

Every Live Workshop from The Analysis Factor includes:

-- All the data, programming code, exercises and handouts you’ll need

--
Live webinars and question & answer sessions

-- Video recordings of all live content for later or repeated review

--The opportunity to ask questions live and to submit questions to be answered between sessions

Hi, I’m Jeff Meyer, your workshop instructor and professional statistical consultant.

I have taught this workshop in the past and have watched students grow in confidence and master count models.

My interests are wide-ranging. I work with linear, binomial, count and mixed models. In addition my work can entail running exploratory and confirmatory models, Structural Equation Models (SEM), latent class analysis and multiple imputation models for missing data. ​​​​​​​

I understand that to be an effective instructor, it takes more than subject matter knowledge and a logical approach to analyzing data. I truly enjoy working with people, and I care about your success!

"Jeff is an excellent instructor. He explained when and how to use the commands in such a clear and understandable manner."

- Previous workshop participant
Prerequisites

So what kind of background in statistics do you need?

This is an advanced-level course. You should have solid experience in running linear models, and experience with ANOVA or linear regression.

We’re assuming you understand:

-- Interpreting regression coefficients

-- Least-squares estimation

-- P-values

-- Dummy coding

-- Interactions

Familiarity with logistic regression will be helpful, but it’s not necessary.

If you have questions about whether you’re ready for this class, just email us. We’ll give you our honest opinion. We want you to succeed!

What others are saying about Analyzing Count Data:

“Loved the real world examples. [The course included] not only useful but practical information.”

-- Anonymous

“The guidance of when and when not to use the different count models available can make a big difference.”
-- Martin Watts, FORCOMP Forestry Consulting Ltd

​​​​​​​“​​​​​​​The workshop covers a range of useful situations for modeling count data. Thus, it provided the opportunity to work with real data, and real count data issues.  At the end of the workshop, one feels as if their analytics tool box can handle a wider variety of jobs.”

-- Carl H. - Graduate Student

As with all our programs, your satisfaction is guaranteed. If you participate fully in this workshop–watch, read, and try out everything included–and find you are not satisfied for any reason, we will give you a full refund, no questions asked. Just notify us within 90 days of purchasing the program.

FAQs

Q. Will I be able to keep up?

You WILL need to spend some time each week, both going over the modules, and also “getting your hands dirty” with some data. Expect to spend 5-8 hours per week reviewing the concepts and doing the exercises, and re-running class examples on your own.

You know how this goes: The more time you put in, the deeper your understanding.

Your registration fee is fully refundable up to 72 hours before your first class session. No refunds will be granted after the program begins.

Q: Do you offer student discounts?

Yes, we do! Current students with a valid ID can register for 40% off the standard rate. Click here to receive our student discount on this and future workshops: http://theanalysisinstitute.com/student-discount/

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Q: Things are very busy at work right now, and I’m afraid I won’t have time to keep up. How much time per week does this really take?

We’ve worked hard to make sure people can do the workshop in the midst of their normal work life. We’ve also built in a week off halfway through the course.

Each workshop instruction session is about 2 hours, whether you attend live or listen to the recording.

Each week, we have a one-hour Q&A session. You don’t have to attend, we just make those available so you can have any questions answered or listen in on others’ questions.

We provide exercises, answers and data sets, so you can practice what you’ve learned each week and get help in the Q&As. These will take you a few hours each week, maybe up to 5 or so. The exercises aren’t required—you’re not graded. But we’ve gotten feedback that they’re very helpful, as it allows you to practice and figure out what you did and didn’t understand.

In other words, each week, there are approximately 2 hours of instruction, one hour of Q&A, and about 2-3 hours of practice time. So if you have a crazy hectic week during the workshop, you have catch up time. But If you have a crazy hectic month, you may be better off waiting to take the class as you won’t really have a chance to catch up.

One reminder: You have access to the workshop website, all materials, and a place to ask questions for a year. So if you get behind, you aren’t missing out. You can catch up on your schedule.

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Q: I teach/work/sleep during this time and cannot attend live. Is there any way to register and access the webinar sessions later?

Yes! We have participants from many time zones with many different work schedules. In order to support our diverse student base, all workshop sessions – including the modules and Q&As — are recorded and made available to students within 48 hours. They’re screenshot video files, so you’ll hear the instructor talking and see his screen, just as live participants do. You can even submit questions for written answers any time between sessions. Many students take the entire workshop in this manner, never attending a session live.

You can also download and keep these videos forever, so if you need to refresh your memory at any point in the future, it’s yours to review.

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Q: I’m outside the U.S. Can I still participate?

Yes. We have participants in our workshops from many different countries. You will want a fast internet connection and either a computer speaker or a telephone if you plan to attend live.

Q: Can I pay with Paypal?

Yes. When you check out, you can pay directly using our system or paying with Paypal. However, the three-payment option is not available using PayPal.

Q: Can I join the Q&A webinars from my iPad or iPhone?

Yes. Attendees have the option of registering and joining the workshop Q&A sessions from your Apple or Android device by downloading a free GoToMeeting app.

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Q: This really isn’t a good time for me. Will you be offering this workshop again soon?