Public Forums for Statistics

Public forums have launched for statistics! These forums are supported by two new members of the OpenIntro team: David Laffie of CSU East Bay and Shannon McClintock of Emory University. Below is a snapshot of the forum view.


Each forum has discussion threads, and these threads can be started by any user, and anyone can reply to the other threads.

If you have questions or feel like helping out others, stop by!


Free textbooks improve learning and the classroom experience

We’ve established that the economic market for textbook is fundamentally broken. But even without that point, there are still many excellent reasons to switch over to a free textbook. First and foremost, using an expensive resource disconnects students. The Expensive Textbook Model is presented below:

The problems that teachers encounter when using expensive textbooks can almost entirely be mitigated by using free resources. Students get immediate and perpetual access to the course textbook, including later editions. Free textbooks also encourage students to focus on learning, not whether they can afford to purchase the textbook.

While this isn’t a novel finding, we encourage you to test it out! Print out this survey for your students.

– David

The flipped classroom, the virtual classroom, and videos

A recent and nicely written article asks “Will the internet replace traditional education?”. This is an interesting question. However replacing traditional education isn’t necessarily the point. Let’s consider the case of videos.

Videos are a key technology for the flipped classroom as well as the virtual classroom.

In the flipped classroom, students use video lessons to preview and review central concepts for their course. This allows the students and instructor to spend more of their class time on the challenging problems traditionally relegated to homework.

In the virtual classroom, students receive all of their instruction via the web. Videos play an even larger role than in the flipped classroom, and interesting problems are fielded electronically by some combination of instructors, teaching assistants, and learning peers.

A common difference in these two approaches is class size, and, by extension, personal interaction with the instructor. In the flipped classroom, class sizes are likely to remain small, or even decrease as active discussion becomes a larger part of the classroom experience. In contrast, the virtual classroom seems poised to embrace hundreds of thousands of students for the most popular material and instructors.

I believe the internet will be revolutionary, but replacing traditional education isn’t necessarily the point. Consider two ways in which the internet is primed to facilitate big changes in education: (i) how we teach, and (ii) who has access. Videos actively invite the re-invention of educational models. However, free educational resources, including videos, will be revolutionary, even if they often find themselves used in traditional classrooms.

In general, I think the future is for tradition, revolution, and education to come together so the largest number of people can teach and learn in a way they find most rewarding.

Cheers, Chris

Second Edition source release + openintro package update

The source of the Second Edition of OpenIntro Statistics is now available at The textbook is written in LaTeX, so if you are unfamiliar with LaTeX but want to try your hand, we recommend reviewing slides from the UCLA Statistical Consulting Center to learn the basics. The second ReadMe file may also be useful in understanding the file organization of the textbook’s source.

Version 1.4 of the openintro package for R is now available on CRAN and includes data sets from the Second Edition. Note that the new package version may take a couple of weeks to propagate to all of CRAN’s mirrors. If you use the install.packages function to update your version of the package, verify you are in fact running version 1.4 after the update (via library(help=openintro)). If the mirror selected did not return the version 1.4, then the version has not yet propagated to that mirror. If this happens, then use the following line of code to download and install the package from the primary CRAN servers in Austria:

install.packages("openintro", repos="", type="source")

Let us know if you have any questions on these releases!


Why the textbook marketplace is fundamentally broken

I stopped by Pearson Education’s booth at a recent statistical conference (JSM) and asked for the prices of their introductory statistics textbooks. They didn’t have such information on hand and seemed surprised that I asked. That was disappointing, and, with such a large organization, it was difficult to believe the lack of pricing information was an accident.

The free market works when supply and demand are in balance. Suppliers develop or manufacture materials and products, and they choose prices so that their products compete for the attention and dollars of consumers. It’s a straightforward system, and it is often incredibly effective. But this is not the way the market works for course textbooks.

Students do not choose which textbook offers the best resource for the price. Rather, teachers do. Market fundamentals do not function when the end-consumer does not choose which particular item they purchase. This doesn’t mean teachers should switch to a model where each student selects her own textbook (that would make for an unmanageable course), but it does mean teachers should pay close attention to price to help rebalance the market.

– David

10,000 textbooks to save $1,000,000 over 2 years

Attention all introductory statistics teachers!

You are invited to participate in the Free Textbook Initiative, a challenge to introductory statistics instructors to save students $1,000,000 by using 10,000 free textbooks before August 2014. This initiative was launched at the Joint Statistical Meetings. Imagine yourself giving a $100 scholarship to each of your students; that’s what you do when you adopt a free textbook. To take part in the effort:

  1. Search: find a free textbook you like. Three textbooks to consider: Two of these books have inexpensive paper copies available. More free textbooks:
  2. Evaluate: ask your students to compare your current textbook to the free textbook of your choosing next term.
  3. Adopt: if student feedback is positive and you are comfortable with the textbook, adopt! If the free textbook isn’t right for you or your students, consider testing a different free textbook.

With free resources, you can “try before you buy”, even if you aren’t paying for anything.

If you are ready to join the movement, the OpenIntro team would love to hear about your and your students’ experiences. OpenIntro is hosting this initiative as a way to both assist and recognize instructors who want to lower financial barriers to education. We’re also here to provide instructor support. To help keep us connected and track your contribution towards the $1,000,000 goal, sign up at


Second Edition release in August

We are excited to announce that the Second Edition of OpenIntro Statistics will be released in August! The First Edition will remain available for one more academic year (2012-2013), or longer if there is continued interest. The Second Edition is a further evolution of OpenIntro Statistics and includes the following important changes:

  • New data. Many of the data sets, some just one or two years old, have been swapped out for newer data and studies. We’ve worked hard to ensure that OpenIntro Statistics remains fresh and current.
  • Updated Chapter 1. Data collection is now featured ahead of the summaries and graphics sections. We include a new research study with surprising results to lead off the textbook and engage students. Two new data sets featuring email and census data take the place of the possum and cars data sets that are present in the First Edition. An important new subsection has also been added that includes intensity maps to highlight the structure of spatial data.
  • Chapter 5 and 6 updates. These chapters previously were structured around large and small samples. Chapter 5 will now introduce inference methods for numerical data, and Chapter 6 will feature methods for categorical data (proportions, contingency tables). The section on ANOVA will be moving from Chapter 8 to Chapter 5 and will remain a “special topic” section.
  • Sample size conditions have evolved slightly. We now set 30 as the standard for using the normal approximation for numerical data and 5 as the minimum expected cell count size for chi-square. With these changes, we also add more strict and explicit conditions regarding skew and table size to ensure the methods remain rigorous and appropriate.
  • New logistic regression section. Chapter 8 includes a brand new section featuring logistic regression in the context of developing a filter for email spam. Our final spam filter isn’t on par with Gmail’s spam filter, but we make a surprising amount of headway in just 9 pages. This new section also highlights ideas and methodology students could see in a second applied statistics course, which makes this new logistic regression section a nice closing act for the content of OpenIntro Statistics and one that is within reach of an advanced or honors introductory statistics course.

As noted, the First Edition will remain available electronically and in print for at least one year — and much longer if there is interest from instructors. The Second Edition will continue the tradition of being priced at cost: about $10 for a paperback and free for the PDF. The Second Edition source will be made available online by the end of August.

We are very excited for the new release! We believe instructors will find it is a natural evolution of OpenIntro Statistics, and one that is easy to use for almost any introductory statistics course to try out or adopt.

Ten minutes a day over one week

One of the biggest challenges instructors face when they want to adopt “open resources” is knowing where to start. Here we’ve outlined 10 minute steps spread over 7 days that can help you get started.

Day 1. Read the rest of this blog post. Optional: It may be helpful to identify when you will have time on each of the next 6 days. For example, commit the 10 minutes right after you get back to your desk from lunch on each day.

Day 2. Download one free textbook, and identify 2 sections from the book’s table of contents that overlap with your class. Here are links to a few of the many available free textbooks: OpenIntro Statistics (more info), Collaborative Statistics (more info), and many others.

Day 3. Briefly skim each of the two sections you identified on Day 2, spending just 5 minutes on each.

Day 4. Pleased with the sections you reviewed? Email your current students a link to the free textbook, or tell them about it in class. Not keen on the book’s explanations, style, or other characteristics? Send David an email and briefly explain why. Your comments are useful for helping these resources improve.

Day 5. Watch the video about free OpenIntro course software (see the gray banner on The video is 13 minutes, so feel free to cut it short to stay under your 10 minute quota.

Day 6. Register as a teacher on (formal verification optional) and create a course with your new account. This process should take no more than 10 minutes. We send emails every 1-2 months to keep instructors up-to-date on OpenIntro and other open resources, but you can opt out anytime.

Day 7. Browse other resources that are available on this Links page. We think you’ll like what you see, and we hope you continue exploring and using these resources. You can always contact us if you want more information. We are also happy to set up phone calls with teachers who interested in learning more about OpenIntro and other open resource projects.

Congratulations, you already completed Day 1!

New Software and Outreach

Happy New Year from OpenIntro,

We’re pleased to share recent news about exciting software developments and broad outreach programs to kick off 2012!

A new version of our free online course management software was released earlier this month. The software now supports four subjects (statistics, algebra, calculus, and physics), and has dozens of other new features. Instructors can manage multiple course simultaneously with class announcements, customizable homepages, and a clean new Question Bank interface. For those who like their mathematics extra fancy, the Question Bank now supports LaTeX notation for equations. Check out our YouTube video for a tour of the latest developments at

This semester also marks our first major outreach effort for OpenIntro Statistics, which we extend to you and your colleagues. If you are already using OpenIntro Statistics in your class, thanks! If you or your colleagues are using an alternative statistics book, we hope you will participate. (1) Request your students to read one section of our textbook during the semester along with the corresponding reading in the course’s regular textbook. (2) Then ask them to fill out an online survey comparing the OpenIntro textbook to their current textbook. (Send us an email and we’ll get back to you with the a link to the appropriate survey.) We hope this will enhance the students’ learning and help us continue to improve OI resources for you and folks around the world.

Thanks for all your support, and best wishes for 2012!

The Openintro Team

Community and state college outreach

We are honored and delighted that our textbook, OpenIntro Statistics, has been adopted as a primary or supplemental text at top research universities (Harvard, Princeton, Duke, and U.Maryland are a few that come to mind) around the country. While this is great news, we’d like to respond to a piece of feedback we received during our recent outreach to community colleges and other teaching-focused schools: the current roster of schools using OpenIntro Statistics has contributed to the misconception that our book is geared solely towards a niche audience of students at top research universities. This couldn’t be further from the truth.

OpenIntro was started when we were students, and that gives us a different take on things. We believe it is possible, and important, to deliver top quality educational tools to everybody who wants them. Our book, website, labs, quizzes, and other resources are available for free, because we want to help people for whom the cost of educational materials is a burden. This makes cost-sensitive students, especially those of community and state colleges, a key audience for us.

From a stylistic perspective, while the textbook is thorough and rigorous, it was also written to make statistics accessible to students who struggle with quantitative subjects. There has been a steady flow of feedback from students who picked up our book on a whim after struggling with a concept presented in their current text or elsewhere on the web. They tell us how happy they are with the simplicity and clarity of how topics were introduced and explained, and we are thrilled to get these reports. This book was written based on our experience teaching and tutoring people of all ages, backgrounds, and enthusiasm levels with the precise goal of being accessible to everybody, especially people for whom statistics doesn’t come easily.

So, in response to recent feedback, we say Thanks for sharing your thoughts with us, and

  • Teachers: We understand that jumping to a new textbook is a big leap in confidence. If this makes you nervous (e.g. you are worried your students won’t like the book), OpenIntro Statistics is the perfect textbook to give a try-out. The book is free to download and cheap to buy, so use the book as a supplement and let your students know you are thinking about a switch. Then ask students for their feedback throughout the course. If they like the old textbook better, no harm done — go back to the old text (we also hope you will let us know how we can improve, since we are here to create products that best serve you and your students!). But if the students like OpenIntro Statistics better, then you have the opportunity to switch over without fear. This is one of the many great features of free and open source resources.
  • If you are a student, try using OpenIntro Statistics as a companion for your class. If you find the book useful, let your teacher know (in a friendly “this was a great resource that I found very useful and you might want to check out for future classes” way, i.e. please don’t be demanding of teachers on this topic since switching textbooks is no small amount of work for teachers). If you don’t like some parts of the book or have suggestions, we’d love to hear from you. Our goal is to maximize the value of students’ eduction, and we want to learn how to improve.

Always Yours,