Complexity Explorer Santa Few Institute

Introduction to Complexity

Lead instructor:


Who is the instructor? Santiago Ortolano Guisasola, Postdoctoral Researcher, Instituto Nacional de Matemática Pura e Aplicada in Rio de Janeiro, Brazil

Video lectures developed by Melanie Mitchell, Professor of Computer Science at Portland State University


How much does it cost? Nothing. The course is completely free.

How is the course funded? The course is funded by the Santa Fe Institute (SFI) and by donations from users. 


Who is the intended audience and what are the prerequisites? This course is intended for anyone with an interest in complex systems. For this introductory course, there are no prerequisites, and no science or math background is necessary. The level is similar to that of an interdisciplinary undergraduate class, though the topics are broad enough to be of interest to people ranging from high school students to professionals. 


What topics are covered? This course is a broad overview of complexity science. There are 10 units; each covers one major topic in complex systems.  See the course syllabus for specific topics.


How does the course work? Each unit consists of a series of short videos, with each video corresponding to subtopics of the unit's main topic. The course website leads you through the videos in order, allowing you to skip or repeat videos as you desire. You can watch these videos at your own pace and in any order you desire; all videos all available indefinitely.  The videos are interspersed with short exercises and quizzes, designed to test your understanding of the material covered in the previous video.  At the end of most units, there is a test (graded automatically), as well as optional, ungraded homework.


On average, participants complete about one unit per week; some will move through the material more quickly, and some more slowly. The course is entirely self-paced so you are welcome to go as quickly or slowly as your schedule and interest allows. You can also pause and return to the course after a few weeks, months or years! 


What about exercises and quizzes? Many videos are followed by short exercises or a quiz that you can do online and that are graded automatically. These exercises and quizzes won’t count towards your final grade; their purpose is to allow you to try out simulations, to see how well you have understood the material in the video, and to see what you might need to review.

What about the exams? Most units will be followed by an exam.  You will take the exam online, and they will be graded automatically.  Your grade for the course will be based on these exams, each of which counts equally.   Everyone who submits all exams and receives an average score of 70% or above will receive a certificate of completion. You may use any of the course materials while taking the test, but we request that you do not consult other sources for answers to test questions in adherence to Complexity Explorer's honor code. Ultimately, participants do not gain from supplying someone else's answer to a question; if you truly want to learn and understand the material, we encourage you to develop your own answer no matter if its right or wrong.

And homework? Most units are followed by an optional homework assignment.  Each homework assignment is a combination of written exercises and experiments with computer simulations using the NetLogo platform (see below).  There will typically be different levels (beginner, intermediate, advanced) to choose from. It will be up to you to choose the level of homework that is appropriate for you. Although your homework will not be graded, we strongly encourage that you do it; it will really help you to better understand the course material!  Solutions to homework assignments will be provided. 


How is the course graded? As described above, your grade will be based on the end-of-unit exams. Your total course score will be your average score over these exams.  Of course, since the course is not for credit, your scores are meant to be for your own tracking of your progress in the course. Complexity Explorer does not share course grade information with anyone.


How well do I need to do to receive a certificate, and will the certificate list my grade? You need to have submitted all of the end-of-unit exams, with an average score of 70% or greater in order to receive a certificate of successful completion. To clarify: You do not need to get 70% or greater on every exam, but as the average over all exams. Your total course grade will be the average of your exam scores.  The certificate will not list your grade; it will simply say that you have successfully completed this course.  You will be able to obtain a copy of your progress report, which does have your exam scores, at any time during or after the course.

Can I get university credit for this course? No, unless a professor at your university has decided to use this course as part of their curriculum.

Will I get any kind of certificate? Everyone who successfully finishes the course will receive a certificate of completion from the Santa Fe Institute and signed by the SFI President and the course instructor. You will also be able to add the certificate to your LinkedIn account.


What is NetLogo and how do I get it? This course uses the Netlogo simulation platform for examples, demonstrations, and homework assignments. NetLogo is a free software package that runs on Windows, Macintosh, and Linux operating systems. No previous experience with NetLogo, or with computer programming, is required. The introductory videos of the course gives instructions on how to download and use Netlogo and further videos teach students the Netlogo language and how to develop their own simulations. If you would like an introduction to NetLogo before starting this course we recommend taking our Fundamentals of NetLogo tutorial by Prof. Bill Rand.  You can download NetLogo at

Will Netlogo run on iPads or other tablets, or on smartphones? No, not yet, though the NetLogo team is working on this. For now you have to run it on a regular computer. Any computer running Windows, Macintosh, or Linux should work with NetLogo. The browser-based version of NetLogo is not recommended for the models included in this course.


Is there a required textbook? No textbook is required.  The lectures will be complemented by numerous suggested readings that will be provided on the course web site.   Some of the units are based in part on Melanie Mitchell's book, Complexity:  A Guided Tour.  This book is a good companion volume to the course, but is not necessary for taking the course. 


In what ways am I allowed to use these resources?  All the materials on this site are available for your use for any non-commercial purpose. All materials (videos, code, write-ups, etc.) are covered by the Creative Commons Attribution-NonCommercial-ShareAlike License ( ). This states that you may copy, distribute, and transmit the work under the condition that you give attribution to, and your use is for non-commercial purposes.


Are subtitles available?  The Complexity Explorer Project has an on-going project in which users volunteer to create subtitles in different languages.  If subtitles are available for a given video they can be accessed in the following way.  First, start and pause the video.  A toolbar will now be visible along the bottom of the video.  Second, click on the gear-shaped button located directly to the right of the “CC” button.  A list of available languages will be shown in the middle drop-down menu located in the box the opens after hitting the gear-shaped button.  Select the language you would like to use for subtitles and click on it.  

How do I download and use subtitles offline? You can download videos and available subtitles to watch offline if you wish. Information on downloading videos is located below under technical requirements.  In order to make the subtitles you download play with the video, you will need to go through a few steps.  Our suggested method is detailed in this help document.  Click the link to download the instructional pdf.   

Can I download a plain text transcript of the video? For any video that has subtitles available, there will also be a plain text transcript (in .txt format) available for download, for each subtitle language available.  When you click on Subtitles & Transcripts you will be given all of the language options available, and you can choose to download either the subtitle or the transcript, or both.  


Do I have to enroll to take the course?   Yes, you need to enroll in order to access the full complement of course materials.  However, enrollment is easy, quick, and free! If you prefer to only watch the videos, those can be accessed through the Complexity Explorer YouTube channel without enrolling in the course.

How do I enroll? Go to, and click the “Enroll” button next to this course. You will be guided through the short enrollment process. You can enroll at any time and take the course at whatever pace you would like. 


How much time does the course require?  You should expect to spend 1–2 hours per unit with the videos, quizzes and exams, and 2–4 hours per unit on homework.


What are the rules on collaboration with other people? You are free, and encouraged, to discuss anything with anyone!  The course website hosts an online forum for students to discuss the course material, homework, etc. However, we ask that the end-of-unit exams be taken entirely on your own, without collaboration with others. We rely on Complexity Explorer's honor code for this and do not employ a mechanism to check if participants violate these expectations.

What is this Forum you've been talking about? The course website hosts a forum in which course participants can post questions, answers, and otherwise discuss the course materials. Questions posted to this forum will be answered by the instructor, teaching assistant, and/or other students.


How do I get the videos to play at a faster rate (e.g., 2x)?  Our videos are streamed through YouTube.  You can opt-in on YouTube for their html5 player, which allows you to speed up or slow down videos.  To opt in, go to

Can I download the videos directly, rather than watching them via YouTube?  Yes, just click on the "Download" button that appears in the Summary view of the Lectures page.  We will also make all the videos for each unit available as zip files on the Supplementary Materials page. 


What if I have more questions? Please address any other questions you have to We would kindly ask that participants not email Dr. Mitchell directly with questions or problems about the course or platform. If you want to express to Dr. Mitchell how much you enjoyed the course, the best place to find her is on Twitter @MelMitchell1