May I read your mind?

(Originally published: 30 July 2012 on YOURblog [Your Official University of Regina blog] at http://www2.uregina.ca/yourblog/?p=6334)

This summer, I’ve taken the lead on some activities that have put me in front of  students who want to learn about computer science. The activities are based on a magic trick. I ask students to pick a number between 0 and 15. I tell them that I will guess their number after asking them only four questions. I show four cards and ask them if their number is on each card ‐ and they only answer “yes” or “no”. I ask if they think that I can do it and they generally say “yes” – but they are still impressed when I succeed! I did this activity on Tuesday with groups from the Science Camp, part of the Summer Sports School. One memorable response from a young camper: “You’re reading our minds!”

Arthur C. Clarke said that any sufficiently advanced technology is indistinguishable from magic. The advanced technology behind the trick is the binary number system that computers use for their computations. A binary digit (bit) can only store “0″ or “1″. Each “yes” becomes a “1″ and each no is “0″. Unknowingly, they tell me their number in binary – I just have to convert it to decimal.

After going over the trick and explaining it we give everyone a set of cards to try at home (cards designed by Alex Clarke). Then we do an implementation of it in either Scratch ( http://scratch.mit.edu/) [a visual programming environment from the Lifelong Kindergarten group at MIT] or App Inventor (http://www.appinventor.mit.edu/) [also from MIT and related to Scratch, but for programming Android cell phones]. These sessions have gone really well.

Guessing numbers inside the Scratch implementation.

In the image you see me in the Scratch version of the guessing game. Within Scratch it is really easy to include images and edit them. It is also possible to record and play sounds within Scratch. The kids have really enjoyed these features. It should also be noted that Scratch is good for building other kinds of games. I encourage parents and teachers to make Scratch available to their kids. There are educator resources available for Scratch at scratch.mit.edu and scratched.gse.harvard.edu. Teachers, if you would like to bring your students to campus so that I can read their minds, please let us know. We may also be able to come to your school. Please send a message to info@cs.uregina.ca to inquire about this.

Computer Science is much more than computer literacy and it is important that our kids not only know how to use computer software but how to build computer software. I’ve been talking about Computer Science outreach since December of 2010. We’ve been building momentum since then. Last December, we organized a professional development day. The idea for the card game came from there, suggested by Pat Vigneron from Notre Dame. Although it is my face in the picture, I am writing on behalf of many people in the Department of Computer Science and in the CSTA who are passionate about bringing CS education to you and your kids. Let us know how we can help you.