On Demand Workshop: Assumptions of Linear Models


Are you checking the wrong assumptions? (Probably…)


Whenever you are collecting and analyzing data, you MUST check your assumptions. Unfortunately, many — if not most — researchers are checking the wrong ones. Or they’re checking the RIGHT assumptions, but with over-conservative tests that are generating “false positives” and finding that every data set fails to meet assumptions.

Unfortunate and frustrating, but not surprising. After all, every statistics textbook lists them slightly differently and has a different way to test them.

It gets even more confusing:

  • Many introductory or beginning statistics classes oversimplify assumptions in order to give a rudimentary introduction. But as your needs increase, your understanding should go deeper as well.
  • Some assumptions are explicitly stated, while others are implicit in the way the model is conceptualized.
  • Some data issues (like multicollinearity and outliers) are important to consider, but they’re not actually assumptions of the model.

So if you try to educate yourself, you’ll end up being MORE confused.

But we’re going to help:


Assumptions of Linear Models
and How to Check Them in SPSS

A 4-Hour Online Tutorial





Karen Grace-MartinI’m Karen Grace Martin, your tutorial instructor for Assumptions of Linear Models and How to Check Them in SPSS.

In this 4-hour online tutorial, we will investigate each of the assumptions of linear models so they make sense. You’ll see why they really aren’t just a list of arbitrary rules.

Then we’ll show you how to check each assumption in SPSS using plots, rules of thumb, and tests, including discussing which tests are too sensitive, and when and how to tell if a plot is “close enough.”

Finally, we’ll have a detailed discussion of your options for dealing with any problems that do arise.

It’s like graduating from following a recipe to really understanding how all the spices and ingredients work together.

Let’s get cooking!



Who Is This Tutorial For?


This tutorial is for you if:

  • You’ll soon need to implement either linear regression or ANOVA, and want to ensure you’re checking assumptions correctly
  • You’ve conducted a linear model in the past and are confused by all the conflicting directions you’ve heard about assumptions and how to check them
  • You’re about to defend your dissertation and want to thoroughly understand your analyses so you’re ready for any questions from your committee
  • You want to deepen your understanding of regression and ANOVA so you can apply them and learn their extensions with confidence
  • You’re comfortable with assumptions but want to finally learn how to interpret the graphs or run transformations with the knowledge you’re doing it right




How Does It Work?


This course is a four-hour online tutorial.

The tutorial and accompanying materials are already available for you to access on your private tutorial website. Log in at any time from any internet-enabled computer, phone, or tablet… all from your own home or office.

In the tutorial videos, the instructor will present concepts and explain the meaning of the techniques, then demonstrate how to check those assumptions in SPSS.



As a participant in the Assumptions of Linear Models and How to Check Them in SPSS tutorial, you’ll have access to a participant-only website, your tutorial “hub.” That’s where you’ll access all tutorial resources and material, including:

  • A set of streaming training videos.

    Watch (and re-watch) these videos on YOUR schedule, as many times as you like, at the speed you desire.

    These videos explain the concepts and steps and gives you step-by-step demonstrations in SPSS.

  • Supplemental PDF handouts.

    You’ll have access to the presentation slides, handy checklists, and worksheets to help you check assumptions on your next model. You can download, print out, and take notes as you follow along.

  • Data files from actual research studies.

    So you can see how to deal with the challenges inherent in real data.

  • Exercises to practice what you’ve learned.

    With answers to check your work.

  • A place to submit written questions.

    Got a question as you’re reviewing the video recording or your notes? Just submit a question in the tutorial website. We’ll answer it right there.

  • Bonus videos.

    To enhance your understanding of where power calculations fit into the data analysis process, we’ve included the following bonus video webinars:

A Review of Logarithms for the Data Analyst (60-minute video presentation)
The 13 Steps to Performing Any Statistical Model (60-minute video presentation)
The First 3 Steps in Running Any Statistical Model: Define and Design (60-minute video presentation)
Getting Started with SPSS Syntax (60-minute video presentation)

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 any time during that 12-month period.

Often, our students report they understand the material at a deeper level on a second or third pass. This stuff is not always easy. You’ll learn more every time, so take advantage of it!




“The examples were easy to understand and including demonstrations in the presentations were very helpful. Having the data sets to play with ourselves in addition to the specific homework exercises really helped to make this a major learning experience. Karen’s slides are so clear and well organized, and she keeps just the right pace. I did not realize online courses could be so effective. Karen is an extremely effective teacher and maximizes use of technology to make this an extremely valuable learning experience.”

— Prue Plummer-D’Amato, PhD
Assumptions of Linear Models Student





What’s Covered in the Tutorial?


The tutorial material is broken into two modules, which are available immediately via the tutorial website.

Module 1: The Assumptions and How to Check Them in SPSS

You will get an accurate understanding of each of the assumptions, both implicit and explicit. In just two hours, you will learn:

  • A brief review of the General Linear Model, in terms of regression and ANOVA, and how it directly and indirectly leads to the assumptions
  • What each assumption really means and why each assumption is important to maintain the integrity of the model and the accuracy of the p-values
  • How to check each assumption using either tests or plots
  • How to construct and read residual plots – how “robust” of a departure from normality or constant variance is acceptable
  • How to construct and read normal probability plots, which are much more accurate than histograms or tests for diagnosing normality
  • Common distributions and situations in which assumptions will likely fail, including count and categorical outcomes, and truncated and censored outcome data

Module 2: Your Options and Strategies If Assumptions Fail

  • What to do if one or more assumptions are not met, including transformations, weighted least squares, and modifying the model
  • All about transformations – the different types, why and how to do them, when to do them, on which variables to do them, and what they mean
  • Box-Cox transformations for determining whether and which transformation will best suit your data
  • A detailed, step-by-step example of how to run a model and check all the assumptions on a real data set (not a perfect textbook example)



Full Tutorial Investment: $97




Your Tutorial from The Analysis Factor Includes:

  • 1 year of access to the tutorial website
  • All the exercises and handouts you’ll need
  • SPSS data sets and code to practice on your own
  • The opportunity to submit questions to be answered on your tutorial website



“Karen gave a very clear and detailed explanation implicit vs. explicit assumptions. I particularly liked the reviews of residual plots. She verified most of what I thought I knew – but I came away with a better idea of when to be concerned enough to apply remedial measures.”

— Assumptions of Linear Models Student


About Your Instructor


I’m Karen Grace-Martin, your tutorial instructor.

As president and founder of The Analysis Factor, I’ve been supporting researchers like you through their statistical planning, analysis, and interpretation since 1997.

With masters degrees in both applied statistics and social psychology, I’ve been honored over the past 15 years to work with everyone from undergrad honors students to Cornell professors, and from non-profit evaluators to corporate data analysts.

After seeing so many smart people get nervous, uncertain, and downright phobic about analyzing their data, I made it my mission to remove the barrier between research and statistical analysis.

I want to banish the confusing jargon that makes eyes glaze over, and instead explain statistical terminology in plain English.

My goal is to help you improve your statistical literacy so you can bring your important research results into the light with confidence.




So what kind of background in statistics do you need?

Our tutorials and workshops are for researchers, not statisticians.

This tutorial, in particular, is created with both the student and professional in mind.

You’ll get the most from this tutorial if you have had at least two statistics classes and some experience in data analysis.

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



“Well-organized. Well-paced. Conceptually difficult statistical material presented in a highly accessible manner.”

— Assumptions of Linear Models Student



Your Satisfaction Is Guaranteed

As with all our programs, your satisfaction is guaranteed. If you participate fully in this tutorial – 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.




Q: Will I be able to keep up with the tutorial material?

If you meet the prerequisites listed above, you’ll be prepared to understand the tutorial materials.

Each module includes about two hours of instructional videos, plus exercises and supplemental materials. We also suggest aside some time (2-3 hours) to re-run class examples attempt the exercises on your own, and watch the bonus videos.

Remember — you also have 12 months to revisit the material! It’s completely on YOUR schedule.

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

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

We’ve worked really hard to make sure people can keep up with the tutorial in the midst of their normal work life. And with on-demand access, you’re all set to deal with unexpected deadlines or “life” emergencies.

The core videos total approximately 4 hours. If you have a crazy hectic month ahead, you can fit watching the materials into your schedule. You can also submit your questions in writing through the tutorial website.

One reminder: You have access to the tutorial 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.

Q: I teach/work/sleep during this time/live outside the U.S and cannot attend at specific times. Is there any way to register and access these sessions later?

Yes! That’s the beauty of our on-demand tutorials. We have participants from many time zones with many different work schedules. In order to support our diverse student base, all tutorial sessions are pre-recorded and available immediately. You can also download and keep these videos forever, so if you need to refresh your memory at any point in the future, all the material is yours to review.

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

Yes. We have participants in our tutorials and workshops from many different countries.

Q: Can I pay with Paypal?

Yes. When you check out, you can pay directly using our system or paying with PayPal.

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

This tutorial (and several others!) is available year-round. You can sign up now and get access to all the course materials (trainings, support, exercises, the option to ask questions, and any additional bonuses). You’ll get all the materials to download and review at your convenience, and you can access them for free any time in the next 12 months.

Plus, ongoing support is included through access to the tutorial website for a full year.

Q: What software do you support for this class?

You will need to know SPSS basics to best understand the tutorial materials.


Have additional questions? We’re here to help! Just email us at support@analysisfactor.com.