What is computer science?
 The study of how process and data can be digitized and
automated.
 Science?
 It’s not about the natural world.
 It does involve experimentation, model-building, and inquiry.
 Math?
 Closest, except…
 Engineering?
 We build things: Important, big, useful things.
 All our human processes are Engineering.
Victims of our Own
Success
 Computer science is not about
using programs.
 Good human-computer interface
design makes CS invisible.
 Students believe CS is about using
Photoshop and Microsoft Office.
 So much of what we teach is seen
as “irrelevant, tedious, and boring.”
Challenges of Computing Education
 Enrollment has declined.
 CS in the Western world is virtually all White or Asian
male.
 Majority female in Islamic world.
 Programming is our most powerful tool, yet we don’t
know how to teach it well.
 Every major study of programming competence in 30
years encounters a floor effect.
 Success rates in introductory courses are 50-70%
worldwide.
US Enrollment in CS
2010 CRA Taulbee Survey of
PhD-granting institutions
Challenges of Computing Education
 What we teach is too useful.
 We know little about learning concepts, because we (and our
students) focus on skills.
 Creates opportunities for developing world…which influences
opinion in developed world.
 We mostly teach how to be a professional software
engineer.
 There are three times as many non-professionals who
program: Badly, inefficiently, with little knowledge.
 We need to be able to teach others about computing, such as
high school teachers.
What works in computing
education
 Teaching in an application context provides relevance.
 Higher pass rates.
 Our tools are nearly-infinitely malleable.
 We can change the interface, but not the cognitive task.
 It’s always about runnable models executed by another
agent.
One-class CS1: Pass (A, B, or C) vs.
WDF (Withdrawal, D or F)
Success Rates in CS1 from Fall 1999 to
Spring 2002 (Overall: 78%)
Architecture
46.7%
Biology
64.4%
Economics
53.5%
History
46.5%
Management
48.5%
Public Policy
47.9%
Media Computation:
Teaching in a Relevant Context
 Presenting CS topics with
media projects and examples
 Iteration as creating negative
and grayscale images
 Indexing in a range as removing
redeye
 Information encodings as
sound visualizations
 Creative, open-ended
assignments.
def clearRed(picture):
for pixel in getPixels(picture):
setRed(pixel,0)
Change in Success rates
in CS1 “Media
Results:CS1“Media
Computation”
Computation” from Spring 2003 to Fall 2005
(Overall 85%)
Architecture
46.7%
85.7%
Biology
64.4%
90.4%
Economics
54.5%
92.0%
History
46.5%
67.6%
Management
48.5%
87.8%
Public Policy
47.9%
85.4%
Wide range of tools and contexts
 Alice, Scratch, Greenfoot, Pleo Dinosaurs, Electric
Pickles
But cognitive task
remains the same.
Where we need Learning Sciences
help
 Teaching the teachers.
 Challenge of CS10K with no
infrastructure, no trappings of
teacher identity.
 Defining CS PCK.
 Measuring knowledge.
 Why care? It’s about equity.