Towards Building Your Own Autograder in NetsBlox Brian Broll

Autograding in Snap! and NetsBlox ● As the name suggests, autograders enable assignments to be automatically graded providing students with immediate feedback. ● Environments like Scratch, Snap!, and NetsBlox have a unique set of challenges for autograding: ○ Lack of clearly defined start state. What if I write a program to draw a square, run it, and then delete all the blocks and submit? ○ Visual program output. How do I specify invariants easily? ○ Required user interaction. What if user interaction is required (like in a game)? ○ Diverse, open-ended projects. These environments have wide walls and students are often given a lot of freedom to create what is important and meaningful to them. How would this be autograded? ○ Required network interaction (and custom protocols). In NetsBlox, student programs may compose a distributed application. This results in another dimension of considerations for autograding (esp. when combined with the aforementioned challenges).

Building Your Own Autograder ● What if we could build our own autograders for Snap! and NetsBlox and enable them via URL parameters (like opening projects)? ● Autograders could be developed, shared, and remixed alongside curriculum (not tightly coupled with any educational platform!) ● This could also facilitate MOOCs using Snap! and NetsBlox with more assessment options

Demo

Next Steps? ● Feedback ○ Give it a try here! ○ Note: Since it is still experimental, things may change! ● Extension support in Snap! so autograders can be used there, too? ● There are many remaining opportunities around autograding: ○ Can we grade more than just custom blocks? ■ Distributed applications? ■ Visual feedback? ■ Interactive applications? ○ Can we give feedback for partial solutions? ○ Should we add support for submitting solutions to platforms like Coursera?

Questions/Comments? Reach out at [email protected] Try it out at https://dev.netsblox.org Thank you!