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Collaborative learning at Caltech

CSA@Caltech uses SKIES (, a collaborative learning app that has been used over the past two years to help teach several undergraduate and graduate classes at Caltech, including genetics (Bi 122), theoretical chemistry (Ch 120), computational chemistry (Ch 121), solar chemistry (Ch 3X), and machine learning (CS 156).

SKIES is a tablet app that provides a “class tree” upon which students and teachers can post cards in a variety of multimedia formats. Typically, the teacher provides a core backbone of lecture cards or lab instructions. To this backbone, students may make quiz questions for each other and share results, and students may attach experimental data, conclusions, open-ended questions, photos of each other, supplemental information they have found online, etc. Everyone can then go through the material together. Using SKIES, classrooms can collaborate; classrooms and subject matter experts can collaborate; and everyone can make lessons together.

In his machine learning class (CS 156), Prof. Abu-Mostafa used SKIES as part of a “flipped classroom” experience. CS 156 is taught as a MOOC offered through edX; it was the first Caltech class to be offered as a MOOC, and has attracted over 200,000 participants since its creation. SKIES provided a useful enhancement to the Caltech students taking the class, by enabling students to submit questions asynchronously prior to and during the class, and enabling TAs to document discussions.

In his genetics class (Bi 122), Prof. Hay populated a class tree with pre-prepared slides. As he lectures, students and teaching assistants add informational cards, flashcards, multiple choice cards, and web links to a class tree. Over the past two years, they have contributed over 1,571 cards to his original 827 lecture slides, with links to original scientific articles, in-class clarifications, and in-depth explanations. After an initial learning curve of less than two weeks, TAs and students add cards at a rapid pace, at an average of one card every 110 seconds for the students, and one card every 170 seconds for the teaching assistants. 

Examples of lecture slides, TA contributions, and student contributions from Bi 122 are shown below.

During lecture, students can quiz themselves using attached questions:

Questions appear directly under lecture slides:

Questions lead to follow-up questions:

Supplemental figures can be added. This one is on Neurospora, a fungus with readily visible mitosis and meiosis products. A student asked in class what the organism looked like, and a TA searched the web and immediately attached a picture.

Students have added hyperlinks to original scientific articles, here on McClintock's experiments demonstrating transposon hopping in corn:

Drawings can be sketched out on the tablet and attached to the tree as well:

Cards stack on top of each other. Here an explanation of different mutation types relevant to tumor formation attracts 20 cards from TAs and students, organized into a pile for easy reference.

 "This would be an excellent question an the exam." Certain in-class comments attract many cards from students. Students also enjoy transcribing stories Prof. Hay relates during lecture, e.g. on the dangers of eating organic peanut butter.

Cards cluster onto important concepts. A zoomed-out view shows how many contributions have been added to the central strand: