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Algorithms on Khan Academy in collaboration with Dartmouth College

What is an algorithm? It’s a sequence of steps that you follow to solve a problem. In everyday life, you might have an algorithm for hanging up your laundry, efficiently going through a shopping list, or finding an empty parking space in a lot. In computer science, an algorithm is a sequence of instructions that a computer program follows. Algorithms form the basis of the most interesting and important programs we use, such as the algorithm that Google uses to calculate driving directions, or the algorithm that Facebook uses to automatically tag you in a photo.

Because algorithms are so important to computer science, they are a core part of a computer science curriculum. The AP CS A class teaches object-oriented programming with algorithms,  every college CS student will have at least one algorithms class and encounter algorithms everywhere, and every software engineer interviewing for a job will review algorithms while they’re prepping for an interview.

Given how important algorithms are, we were elated when Dartmouth professors Thomas Cormen and Devin Balkcom suggested writing an online course on Algorithms, available to anyone for free, forever, on Khan Academy. If you’re a college CS student, you might recognize the name “Cormen” - he’s the “C” in the “CLRS”-authored Algorithms textbook, the most popular algorithms textbook used by college classes. Balkcom is a fellow professor at Dartmouth, and he’s actually rewritten their introductory CS class, so he’s an expert in teaching algorithms to new computer science students.

 We worked over the summer to create an introductory Algorithms class that’s highly interactive. Algorithms can be hard to wrap your head around, so we have both step-by-step diagrams and interactive visualizations to explain each algorithm:

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We also want to give you a chance to try coding the algorithms yourself, so we’ve used our JavaScript coding challenge framework to write 19 challenges with unit tests (and you’ll have to write unit tests yourself!):

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We’ve also sprinkled in a few quizzes, to make sure you understand concepts like asymptotic and graph notation:

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This curriculum covers everything you’d find in an intro course - asymptotic notation, binary search, selection/insertion sort, recursion, merge/quick sort, graph representation, and breadth first search. There’s much more to cover, of course, including going more into how you can design your own algorithms, but we’re so excited about what we have now and how much it could help software engineers in all stages of life that we want to get it in your hands now.

Please dive into the course and let us know what you think - you can leave comments beneath the articles, or email us more detailed feedback at compsci-feedback@khanacademy.org.

Thank you again to Thomas Cormen, Devin Balkcom, and their supporting staff at Dartmouth for making this Algorithms class a possibility.

Posted by Pamela Fox, Khan Academy.

 

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Khan Lab School Opening Day

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Back in June we told you that we’d be experimenting with a learning lab, and today marks the opening of the Khan Lab School, which will be composed of a small cohort of around 30 students.

Khan Academy has a history of summer camps and working with classrooms, which have both really helped us better understand opportunities to help teachers and students.

In order to take an even more hands-on and sustained approach, the Khan Lab School will research blended learning and education innovation by creating a working model of Khan Academy’s philosophy of learning in a physical school environment and sharing the learnings garnered with schools and networks around the world.

Our goal is to develop new, personalized practices that center around the student. As this model is developed, we will be sharing and testing the practices in diverse settings to offer new ways of thinking about Khan Academy and the classroom.

The lab school will focus on developing practices that empower students to realize that they can shape the systems and solve problems of the world through their own character, intellect, and passion.

There are already thousands of classrooms across the world that are using Khan Academy. We learn so much from these classrooms and try to share those learnings with other schools and educators. A small-scale lab school helps us further explore how physical environments can be reimagined and blended with online tools to empower teachers and students.

The intent is not just to develop practices, but also to share them in ways most likely to effect broad change. We intend to further share with the world through in-house research fellowships, teacher workshops, videos, publications, and the broader Khan Academy platform.

As this is a research lab school, it is not open for general enrollment at this time. But if you’d like to be on an email list to hear more about the lab school in the coming months, you can sign up here.

- Jason Pittman, Head Teacher, on behalf of the Khan Lab School team

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Start your 13.8 billion-year journey with the Big History Project

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The Big History Project is now available on Khan Academy. Whether you’re a solo learner or a classroom teacher, get ready to take a self-paced journey through nearly 14 billion years of history in just 10 tutorials!

Big History asks the big questions about our universe, our planet, life and humanity. From the Big Bang to our still-expanding universe, this course, created and maintained by the Big History Project, will lead students on a journey of astounding connections and exciting discoveries. 

The lessons also draw upon the insights of history, chemistry, biology, anthropology, physics, and a variety of other disciplines. Teacher-created lessons include downloadable activities, engaging videos, animations, and articles that bring the voices of leading scholars from around the world to you…and bring history to life.

Today, there’s more information available to us on our phones than was available in all the great libraries of Alexandria, so how do we decide what claims we can trust? Big History guides learners through examining their intuition, looking at the authority, evidence, and logic of claims.

Big History also looks beyond the timeline of human history to explore the connections between distant events billions of years ago and our lives today.

From the massive expanse of the universe to the smallest of atoms, Big History guides you to think across temporal and physical scales.

Both in articles and at the end of each tutorial, students and teachers can access downloadable and printable classroom resources such as lesson transcripts, video transcripts, worksheets and answer keys. Quizzes and glossary challenges allow teachers to assess student comprehension.

Start your journey now!

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An online helping hand to get you from here to college

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As part of the White House Expanding College Access Initiative, we’ve created an in-depth college admissions resource for high school students and college counselors across the country.

Our college admissions content covers the high school journey, providing college guidance whether you’re a senior or a freshman. It takes a holistic approach: from overcoming cultural barriers to step-by-step walkthroughs for the Common App and FAFSA forms. The site includes sections on considering college as an option, understanding how your high school record counts towards college, navigating different college options, writing college applications, and applying for financial aid. We’ve designed this site for students who’d like to access the site on their own, but it can be equally integrated into counsellor-student guidance sessions.

This site is a collective effort from over nine months of research: it contains 100+ informational videos covering the college admissions process from start to finish, broken down into simple, understandable pieces. We’ve drawn on the expertise of admissions and financial aid officers from top public and private colleges, high school guidance counselors, and current college students from around the country.

We hope you find the college admissions resources useful as you embark on your college journey!

 

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Video tasks on the learning dashboard

Khan Academy is now introducing video tasks on the learning dashboard. Prior to this release, the mission dashboard consisted exclusively of practice and mastery tasks–problems to practice and interact with the skills. If a student didn’t know how to do a particular exercise, they would have to rely on the video in the specific skill or manually look up the video, and there was no way to know ahead of time which videos are particularly useful and which aren’t. With this in mind, we decided to research which videos on our site are most effective in helping people learn. We then wanted to explore how we could make sure students see these videos when trying to learn related skills.

Many of our exercises are tagged with “curated related videos”—videos that are hand-selected as related to the exercise. Using this as a starting point, we looked at all the videos that were already tagged as related to any exercise. For each of these videos, we compared the accuracy on its associated exercise both before watching the video and after watching it. From there, we selected the top fifty most effective videos, each improving the accuracy on its associated exercise by at least twenty percent, and are now highlighting them on the mission dashboard. When the system recommends an exercise with an associated video on the list of our top fifty related videos, it will automatically recommend the related video as well. Similarly, when an exercise with an associated video task is manually added to a student’s list of exercises as a personal task, the video task will also be added automatically.

A student might watch the video before attempting the exercise, which is why we place the video tasks immediately above its associated exercise. Alternatively, a student may want to attempt the exercise first, and if they struggle with the exercise then they can close it out temporarily and watch the video before trying again.

If a student doesn’t need to watch the video, the video task can disappear in three ways. If the student watches the video, the video task will never reappear for that student. The student can also remove the video task without watching it and it will never again be shown to them. Finally, if the student completes the associated exercise and renavigates to the mission dashboard (refreshing the page, e.g.), the video task will also go away. However, in this last scenario, if the exercise ever reappears on the mission dashboard of this student, the video task will also return.

We sincerely hope you find this update as exciting and useful as we do!

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