Interactive Demos of Error Detection Magic Tricks

This page links to interactive demos of various error detection magic tricks described in:

Ronald I. Greenberg. Educational magic tricks based on error-detection schemes. In Proceedings of the 22nd Annual SIGCSE Conference on Innovation and Technology in Computer Science Education, pages 170–175. ACM SIGCSE, July 2017. Bologna, Italy. https://doi.org/10.1145/3059009.3059034

with these overview slides The paper and supplemental materials also can be found in this Loyola eCommons entry: https://ecommons.luc.edu/cs_facpubs/149.

These tricks are labeled in the paper as:

The above links will bring the tricks up at the default sizes noted above; for Versions 1, 2a, and 2b, one can also append, for example, "&n=12", to work with a 12 x 12 grid. (In version 2b, the size will be "rounded" up to a value that is 1 mod 3.) In version 5, one may append, e.g., "&d=4" to obtain a 2^4 x 2^4 grid.

Also see the following implementation notes, including details on how to perform each trick, and compact HTML/JavaScript source listing. (Note that the description for Version 5 with the 8x8 grid indicates working with grid divisions of quadrants, separated row pairs, and separated column pairs, which is easier to visualize, while the actual implementation uses different slices that are easier to program, but it can be proved that the approaches are equivalent.)