Thu, 05 Jan 2012 20:09:39
Fall ‘11 intern David Hu created this incredible video about his experience at Khan.
Teach ALL the Humans.
If you want to change the world like David, sign up at khanacademy.org/r/jobs
Wed, 02 Nov 2011 16:56:59
Khan Academy developer David Hu writes a very interesting piece about how we’re running a number of experiments to improve our understanding of student mastery and encourage more learning from our students:
In high level terms, we increased overall interest — more new exercises attempted, fewer problems done per proficiency — without lowering the bar for proficiency — P(next problem correct | just gained proficiency) was roughly the same for both groups. Further, it seemed that overall learning, as measured by the distribution of accuracies obtained, went up slightly under the new model.
Optimistically, we hypothesise that our gains are from moving students quicker off exercises they’re good at, while making them spend more time on concepts in which they need more practice.
Fri, 01 Apr 2011 14:48:00
New exercises have been dropping by our knowledge map, and it’s time to give them a proper welcome!
This week, we added exercises that introduce basic angle concepts, such as acute, obtuse, right, complementary, and supplementary angles. Each exercise has a narrow focus to keep things simple (and to let you rack up those energy points!). If the exercises are too granular for your taste, try the harder ones first — achieving proficiency in “Complementary and supplementary angles” will make you proficient in “Complementary angles” and “Supplementary angles”.
We also added exercises on writing and evaluating expressions. What about those pesky expressions with unknown variables? Don’t worry, we cover that too. You might have played around with the linear equations module and the absolute value module, and now you can experience both concepts in the “Absolute value equations” module. Likewise for radical equations.
And that’s not all! We added two more types of word problems, and you’ll notice a slick new solid geometry module. There are a few more challenging exercises too, from logarithms to nested functions to the quotient rule.
Special thanks to Omar, Desmond, Eric, Jens, and Rock for their contributions!
Until next time,
Fun with angles:
— Angle types
— Degrees to radians
— Radians to degrees
— Radians and degrees
— Complementary angles
— Supplementary angles
— Complementary and supplementary angles
Fun with expressions and equations:
— Writing expressions 1
— Writing expressions 2
— Evaluating expressions
— Expressions with unknown variables
— Expressions with unknown variables 2
— Absolute value equations
— Radical equations 1
— Arithmetic word problems
— Rate problems
— Solid geometry
— Logarithms 2
— Range of a function
— Functions 3
— Quotient rule
Wed, 23 Feb 2011 15:21:00
About a week ago we launched Khan Academy user profiles. Profiles are meant to round out the previous work we’d done on the design of the knowledge map, exercise interface, and badges by bringing all of the information about your performance on the site into a single interface.
There were a few competing design goals here, but the most important one was to flesh out what it means to “progress” within the Khan Academy. At a high level, the page breaks down into a few major sections
- A set of top level stats that emphasize completion of exercises and videos
- Vital Statistics: A completely new set of tools for measuring work: Activity, Focus, and exercise completion
- Achievements: A clearer summary and more interactive badge explorer
- Recent Activity: Pretty straight forward, but coalesces information that was previously hard to see
The original version of Khan Academy included stars (proficient exercises) and points (a measure of effort). When we added badges, and the badge summary page, it turned into the easiest way to measure progress because that information was so neatly summarized for users. It was never our intent to have badges be a primary motivator for the majority of users, but the lack of a profile was mildly distorting the experience for some users. While badges, stars, and points remain important, we wanted to make profiles a powerful metacognitive tool for students in the same way that the knowledge map helps them understand the interconnectedness of the topics in Math.
Don’t dumb it down
Kids are smarter than we give them credit for. No one likes being patronized at any age, but all too often software patronizes students. Things like overly kid-like color schemes, oversized buttons, and over-simplified user interface are only really appropriate for *very* young children because they send a clear message to everyone about what you think of their level of intelligence/expertise. After spending several hours observing and interviewing 5th graders, I am happy to report that they are more sophisticated and willing to experiment/explore than many adult users I’ve worked with.
The Focus graph shows how a student has divided their time on the site over the selected time period.
This is a complex graph in some ways, but it also engenders some visceral reactions, like, is it simple looking or busy? A student/teacher might not at first glance notice that on the exercise ring we show a star next to any module name that you’ve earned proficiency in, but when a user hovers the exercise the tooltip will explain what the star means. Our goal here was interesting at a glance but not necessarily completely obvious. The other important design decision on the graphs is that we didn’t use absolute scales anywhere. The result is that whether you spend 5 minutes or two hours on the site each day, the information remains visually interesting and useful.
Make it cool
We want students to start to identify themselves with the information that we’re showing in the profile. We want them to think it’s cool to have finished 80 math modules. As Ben has pointed out, grades are kind of boring in the grand scheme of things. Khan Academy profiles are designed to be visually compelling and highly interactive. Every chart provides tooltips and drill down capability (with back button functionality preserved). This gives a feeling of depth and allows students to explore/discover the connection between different metrics.
And what’s cooler than success, right? It’s one of the most addictive feelings in the world. So many students struggle with the feeling of failure, and constant absolute measures like grades only exacerbate the problem. Not everyone is going to move at the same pace, and so we owe it to students to find meaningful and interesting progress indicators that include both absolute and relative measures. Profiles were specifically designed to provide measures that help students better understand their own educational progress, set goals for themselves, and measure themselves against those goals. The good news is that it really seems to be working.
What do you think?
In Ben’s original post on what you guys wanted to see in user profiles there were a ton of good discussions and ideas generated. Are you using profiles? If so, are they interesting to you? Missing something important? Are there things you like/dislike about the design itself (especially if you’ve had trouble/confusion while trying to use profiles)?
Wed, 23 Feb 2011 11:25:00
“You make what you measure” is such a popular belief around the tech community that it’s become something of a status symbol to design and blog about your custom, gorgeous, flat-screen status board that sits in the hallway and shows off your company’s key metrics. The belief is that just by measuring and drawing daily attention to your most important numbers, they’ll start going up. These guys are making a business out of it. Fog Creek has a gorgeous one made by Rob Sobers*.
It’s basically impossible to see a big, beautiful number every single day and not start optimizing it. That’s why we want to know: what data do you want to see daily on your personal Khan Academy dashboard?
Panic’s visualization of critical data vs. the boring old report card.
We need to make better use of this technique in education. The Khan Academy has a ton of data about learners’ performance: which videos they’ve watched, when and how much they watched, how their performance on various math exercises has changed over time, and more. By exposing each Khan Academy user to the best metrics we’ve got, we’ll give them a chance to start optimizing for something other than ‘A+’, ‘A’, and ‘A-‘. I can’t think of a more succinct explanation of the current grade inflation problem than, “You make what you measure.”
That’s why we’re hacking away like crazy on user profiles right now. Every single user will have access to their own personal profile with all types of interesting statistics. Here are some experimental teasers:
Recent progress and achievements earned across specific concepts
Quick glimpse at student’s overall focus
Our challenge, and it’s not an easy one, is to find the data most strongly correlated with real educational progress and expose those numbers to students in an appealing way. Then they’ll do all the hard work. Think stuff like “new concepts attempted, studied with videos, and provably mastered in our exercises.”
We’re gonna start off simple with the few key metrics students and teachers are dying for right now. Bigger plans are on the horizon.
So what data do you want to see on your Khan Academy profile?
*I keep trying to get Rob to open source some of that gorgeous dashboard code. We’d definitely make use of it somewhere.