May 30, 2016 8:43 AM
"The One Form of Poverty That Should Be Shunned"
In her essay "The Importance of Being Scared", poet Wislawa Szymborska talked about the fairy tales of Hans Christian Andersen, which were often scary in ways that are out of sync with modern sensibilities. Of Andersen, she wrote:
He didn't believe that you should try to be good because it pays (as today's moral tales insistently advertise, though it doesn't necessarily turn out that way in real life), but because evil stems from intellectual and emotional stuntedness and is the one form of poverty that should be shunned.
I love that phrase: "the one form of poverty that should be shunned", as well as Andersen's prescription.
I need to read more Szymborska. She is often quite funny. This book review quotes a passage from the review of a book on caves that made me smile:
The first to discover caves were of course those animals who could find their way in the dark. Cavemen, who had already lost this gift, couldn't venture too far into their caves. They had to stick to the edges. It's not that they didn't have the nerve, they just didn't have flashlights.
That joke hits close to home in my work as a programmer and teacher, and even as department head. Sometimes, I don't need more nerve. I need a flashlight.
May 27, 2016 1:38 PM
Brilliance Is Better Than Magic, Because You Get To Learn It
Brent Simmons has recently suggested that Swift would be better if it were more dynamic. Some readers have interpreted his comments as an unwillingness to learn new things. In Oldie Complains About the Old Old Ways, Simmons explains that new things don't bother him; he simply hopes that we don't lose access to what we learned in the previous generation of improvements. The entry is short and worth reading in its entirety, but the last sentence of this particular paragraph deserves to be etched in stone:
It seemed like magic, then. I later came to understand how it worked, and then it just seemed like brilliance. (Brilliance is better than magic, because you get to learn it.)
This gets to close to the heart of why I love being a computer scientist.
So many of the computer programs I use every day seem like magic. This might seem odd coming from a computer scientist, who has learned how to program and who knows many of the principles that make complex software possible. Yet that complexity takes many forms, and even a familiar program can seem like magic when I'm not thinking about the details under its hood.
As a computer scientist, I get to study the techniques that make these programs work. Sometimes, I even get to look inside the new program I am using, to see the algorithms and data structures that bring to life the experience that feels like magic.
Looking under the hood reminds me that it's not really magic. It isn't always brilliance either, though. Sometimes, it's a very cool idea I've never seen or thought about before. Other times, it's merely a bunch of regular ideas, competently executed, woven together in a way that give an illusion of magic. Regular ideas, competently executed, have their own kind of beauty.
After I study a program, I know the ideas and techniques that make it work. I can use them to make my own programs.
This fall, I will again teach a course in compiler construction. I will tell a group of juniors and seniors, in complete honesty, that every time I compile and execute a program, the compiler feels like magic to me. But I know it's not. By the end of the semester, they will know what I mean; it won't feel like magic to them any more, either. They will have learned how their compilers work. And that is even better than the magic, which will never go away completely.
After the course, they will be able to use the ideas and techniques they learn to write their own programs. Those programs will probably feel like magic to the people who use them, too.
May 23, 2016 1:55 PM
Your Occasional Reminder to Use Plain Text Whenever Possible
The authors of Our Lives, Encoded found that they had lost access to much of their own digital history to the proprietary data formats of long-dead applications:
Simple text files have proven to be the only format interoperable through the decades. As a result, they are the only artifacts that remain from my own digital history.
I myself have lost access to many WordPerfect files from the '80s in their original form, though I have been migrating their content to other formats over the years. I was fortunate, though, to do most of my early work in VMS and Unix, so a surprising number of my programs and papers from that era are still readable as they were then. (Occasionally, this requires me to dust off troff to see what I intended for them to look like then.)
However, the world continues to conspire against us. Even when we are doing something that is fundamentally plain text, the creators of networks and apps build artificial barriers between their services.
One cannot simply transfer a Twitter profile over to Facebook, or message a Snapchat user with Apple's iMessage. In the sense that they are all built to transmit text and images, these platforms aren't particularly novel, they're just designed to be incompatible.
This is one more reason that you will continue to find me consorting in the ancient technology of email. Open protocol, plain text. Plenty of goodness there, even with the spam.
May 18, 2016 11:27 AM
Confusion is the Sweat of Learning
That's a great line from Rhett Allain in Telling You the Answer Isn't the Answer:
Students are under the impression that when they are stuck and confused, they are doing something wrong. Think of it this way. What if you went to the gym to work out but you didn't get sweaty and you weren't sore or tired? You would probably feel like you really didn't get any exercise. The same is true for learning. Confusion is the sweat of learning.
As I read the article, I was a little concerned that Allain's story comes from a physics course designed for elementary education majors... Shouldn't education majors already know that learning is hard and that the teacher's job isn't simply to give answers? But then I realized how glad I am that these students have a chance to learn this lesson from a teacher who is patient enough to work through both the science and the pedagogy with them.
One of the biggest challenges for a teacher is designing workouts that ride along a thin line: confusing students just enough to stretch them into learning something valuable, without working them so hard that they become disheartened by the confusion and failure. This is hard enough to do when working with students individually. The larger and more diverse a class is, the more the teacher has to start shooting for the median, designing materials that work well enough often enough for most of the students and then doing triage with students on both ends of the curve.
Another is helping students learn to appreciate the confusion, perhaps even relish it. The payoff is worth the work.
May 15, 2016 9:36 AM
An Interview about Encryption
A local high student emailed me last week to say that he was writing a research paper about encryption and the current conversation going on regarding its role in privacy and law enforcement. He asked if I would be willing to answer a few interview questions, so that he could have a few expert quotes for his paper. I'm always glad when our local schools look to the university for expertise, and I love to help young people, so I said yes.
I have never written anything here about my take on encryption, Edward Snowden, or the FBI case against Apple, so I figured I'd post my answers. Keep in mind that my expertise is in computer science. I am not a lawyer, a political scientist, or a philosopher. But I am an informed citizen who knows a little about how computers work. What follows is a lightly edited version of the answers I sent the student.
Do you use encryption? If so, what do you use?
Yes. I encrypt several disk images that hold sensitive financial data. I use encrypted files to hold passwords and links to sensitive data. My work laptop is encrypted to protect university-related data. And, like everyone else, I happily use https: when it encrypts data that travels between me and my bank and other financial institutions on the web.
In light of the recent news on groups like ISIS using encryption, and the Apple v. Department of Justice, do you
support legislation that eliminates or weakens powerful encryption?
I oppose any legislation that weakens strong encryption for ordinary citizens. Any effort to weaken encryption so that the government can access data in times of need weakens encryption for all people at all times and against all intruders.
Do you think the general good of encryption (protection of data and security of users) outweighs or justifies its
usage when compared to the harmful aspects of it (being used by terrorists groups or criminals)?
I do. Encryption is one of the great gifts that computer science has given humanity: the ability to be secure in one's own thoughts, possessions, and communication. Any tool as powerful as this one can be misused, or used for evil ends.
Encryption doesn't protect us from only the U.S. government acting in good faith. It protects people from criminals who want to steal our identities and our possessions. It protects people from the U.S. government acting in bad faith. And it protects people from other governments, including governments that terrorize their own people. If I were a citizen of a repressive regime in the Middle East, Africa, Southeast Asia, or anywhere else, I would want the ability to communicate without intrusion from my government.
Those of us who are lucky to live in safer, more secure circumstances owe this gift to the people who are not so lucky. And weakening it for anyone weakens it for everyone.
What is your response to someone who justifies government suppression of encryption with phrases like "What are you
hiding?" or "I have nothing to hide."?
I think that most people believe in privacy even when they have nothing to hide. As a nation, we do not allow police to enter our homes at any time for any reason. Most people lock their doors at night. Most people pull their window shades down when they are bathing or changing clothes. Most people do not have intimate relations in public view. We value privacy for many reasons, not just when we have something illegal to hide.
We do allow the police to enter our homes when executing a search warrant, after the authorities have demonstrated a well-founded reason to believe it contains material evidence in an investigation. Why not allow the authorities to enter or digital devices under similar circumstances? There are two reasons.
First, as I mentioned above, weakening encryption so that the government can access data in times of legitimate need weakens encryption for everyone all the time and makes them vulnerable against all intruders, including bad actors. It is simply not possible to create entry points only for legitimate government uses. If the government suppresses encryption in order to assist law enforcement, there will be disastrous unintended side effects to essential privacy of our data.
Second, our digital devices are different than our homes and other personal property. We live in our homes and drive our cars, but our phones, laptops, and other digital devices contain fundamental elements of our identity. For many, they contain the entirety of our financial and personal information. They also contain programs that enact common behaviors and would enable law enforcement to recreate past activity not stored on the device. These devices play a much bigger role in our lives than a house.
In 2013 Edward Snowden leaked documents detailing surveillance programs that overstepped boundaries spying on
citizens. Do you think Snowden became "a necessary evil" to protect citizens that were unaware of surveillance
Initially, I was unsympathetic to Snowden's attempt to evade detainment by the authorities. The more I learned about the programs that Snowden had uncovered, the more I came to see that his leak was an essential act of whistleblowing. The American people deserve to know what their government is doing. Indeed, citizens cannot direct their government if they do not know what their elected officials and government agencies are doing.
In 2013 to now, the number of users that are encrypting their data has significantly risen. Do you think that
Snowden's whistleblowing was the action responsible for a massive rise in Americans using encryption?
I don't know. I would need to see some data. Encryption is a default in more software and on more devices now. I also don't know what the trend line for user encryption looked like before his release of documents.
Despite recent revelations on surveillance, millions of users still don't voluntarily use encryption. Do you
believe it is fear of being labeled a criminal or the idea that encryption is unpatriotic or makes them an evil
I don't know. I expect that there are a number of bigger reasons, including apathy and ignorance.
Encryption defaults on devices like iPhones, where the device is encrypted while locked with a passcode is becoming
a norm. Do you support the usage of default encryption and believe it protects users who aren't computer savvy?
I like encryption by default on my devices. It comes with risks: if I lose my password, I lose access to my own data. I think that users should be informed that encryption is turned on by default, so that they can make informed choices.
Should default encryption become required by law or distributed by the government to protect citizens from foreign
governments or hackers?
I think that we should encourage people to encrypt their data. At this point, I am skeptical of laws that would require it. I am not a legal scholar and do not know that the government has the authority to require it. I also don't know if that is really what most Americans want. We need to have a public conversation about this.
Do you think other foreign countries are catching up or have caught up to the United States in terms of technical
prowess? Should we be concerned?
People in many countries have astonishing technical prowess. Certainly individual criminals and other governments are putting that prowess to use. I am concerned, which is one reason I encrypt my own data and encourage others to do so. I hope that the U.S. government and other American government agencies are using encryption in an effort to protect us. This is one reason I oppose the government mandating weakness in encryption mechanisms for its own purposes.
The United States government disclosed that it was hacked and millions of employees information was compromised.
Target suffered a breach that resulted in credit card information being stolen. Should organizations and companies be
legally responsible for breaches like these? What reparations should they make?
I am not a lawyer, but... Corporations and government agencies should take all reasonable precautions to protect the sensitive data they store about their customers and citizens. I suspect that corporations are already subject to civil suit for damages caused by data breaches, but that places burdens on people to recover damages for losses due to breached data. This is another area where we as a people need to have a deeper conversation so that we can decide to what extent we want to institute safeguards into the law.
Should the US begin hacking into other countries infrastructures and businesses to potentially damage that country
in the future or steal trade secrets similar to what China has done to us?
I am not a lawyer or military expert, but... In general, I do not like the idea of our government conducting warfare on other peoples and other governments when we are not in a state of war. The U.S. should set a positive moral example of how a nation and a people should behave.
Should the US be allowed to force companies and corporations to create backdoors for the government? What do
believe would be the fallout from such an event?
No. See the third paragraph of my answer to #4.
As I re-read my answers, I realize that, even though I have thought a lot about some of these issues over the years, I have a lot more thinking to do. One of my takeaways from the interview is that the American people need to think about these issues and have public conversations in order to create good public policy and to elect officials who can effectively steward the government in a digital world. In order for this to happen, we need to teach everyone enough math and computer science that they can participate effectively in these discussions and in their own governance. This has big implications for our schools and science journalism.
May 11, 2016 2:45 PM
Why Do Academic Research in Programming Languages?
When people ask Jean Yang this question, she reminds them that most of the features in mainstream languages follow decades of research:
Yes, Guido Van Rossum was a programmer and not a researcher before he became the Benevolent Dictator of Python. But Python's contribution is not in innovating in terms of any particular paradigm, but in combining well features like object orientation (Smalltalk, 1972, and Clu, 1975), anonymous lambda functions (the lambda calculus, 1937), and garbage collection (1959) with an interactive feel (1960s).
You find a similar story with Matz and Ruby. Many other languages were designed by people working in industry but drawing explicitly on things learned by academic research.
I don't know what percentage of mainstream languages were designed by people in industry rather than academia, but the particular number is beside the point. The same is true in other areas of research, such as databases and networks. We need some research to look years and decades into the future in order to figure what is and isn't possible. That research maps the terrain that makes more applied work, whether in industry or academia, possible.
Without academics betting years of their career on crazy ideas, we are doomed to incremental improvements of old ideas.
May 07, 2016 10:55 AM
Without Wonder, Without Awe
Henry Miller, in "The Books in My Life" (1969):
Every day of his life the common man makes use of what men in other ages would have deemed miraculous means. In the range of invention, if not in powers of invention, the man of today is nearer to being a god than at any time in history. (So we like to believe!) Yet never was he less godlike. He accepts and utilizes the miraculous gifts of science unquestioningly; he is without wonder, without awe, reverence, zest, vitality, or joy. He draws no conclusions from the past, has no peace or satisfaction in the present, and is utterly unconcerned about the future. He is marking time.
It's curious to me that this was written around the same time as Stewart Brand's clarion call that we are as gods. The zeitgeist of the 1960s, perhaps.
"The Books in My Life" really has been an unexpected gift. As I noted back in November, I picked it up on a lark after reading a Paris Review interview with Miller, and have been reading it off and on since. Even though he writes mostly of books and authors I know little about, his personal reflections and writing style click with me. Occasionally, I pick up one of the books he discusses, ost recently Richard Jefferies's The Story of My Heart.
When other parts of the world seem out of sync, picking up the right book can change everything.
May 06, 2016 2:25 PM
Important Sentences about Learning Styles
... it seems to me that the important "takeaway" from the research on learning styles is that teachers need to know about learning styles if only to avoid the trap of teaching in the style they believe works best for them. As long as teachers are varying their teaching style, then it is likely that all students will get some experience of being in their comfort zone and some experience of being pushed beyond it. Ultimately, we have to remember that teaching is interesting because our students are so different, but only possible because they are so similar. Of course each of our students is a unique individual, but it is extraordinary how effective well-planned group instruction can be.
Variety is an essential element of great teaching, and one I struggle to design into my courses. Students need both mental comfort and mental challenge. Changing pace every so often allows students to focus in earnest for a while and then consolidate knowledge in slower moments. Finally, changing format occasionally is one way to keep things interesting, and when students are interested, they are more willing to work. And that's where most learning comes from: practice and reflection.
May 05, 2016 1:45 PM
In her 1942 book Philosophy in a New Key, philosopher Susanne Langer wrote:
A question is really an ambiguous proposition; the answer is its determination.
This sounds like something a Prolog programmer might say in a philosophical moment. Langer even understood how tough it can be to write effective Prolog queries:
The way a question is asked limits and disposes the ways in which any answer to it -- right or wrong -- may be given.
Try sticking a cut somewhere and see what happens...
It wouldn't be too surprising if a logical philosopher reminded me of Prolog, but Langer's specialties were consciousness and aesthetics. Now that I think about it, though, this connection makes sense, too.
Prolog can be a lot of fun, though logic programming always felt more limiting to me than most other styles. I've been fiddling again with Joy, a language created by a philosopher, but every so often I think I should earmark some time to revisit Prolog someday.
May 03, 2016 4:19 PM
Pair Programming is a Skill to be Learned
David Andersen offers a rather thorough list of ways that academics might adapt Google's coding practices to their research. It's a good read; check it out! I did want to comment on one small comment, because it relates to a common belief about pair programming:
But, of course, effective pair programming requires a lot of soft skills and compatible pairs. I'm not going to pretend that this solution works everywhere.
I don't pretend that pair programming works everywhere, either, or that everyone should adopt it, but I often wonder about statements like this one. Andersen seems to think that pair programming is a good thing and has helped him and members of his team's to produce high-quality code in the past. Why downplay the practice in a way he doesn't downplay other practices he recommends?
Throughout, the article encourages the use of new tools and techniques. These tools will alter the practice of his students. Some are complex enough that they will need to be taught, and practiced over some length of time, before they become an effective part of the team's workflow. To me, pair programming is another tool to be learned and practiced. It's certainly no harder than learning git...
Pair programming is a big cultural change for many programmers, and so it does require some coaching and extended practice. This isn't much different than the sort of "onboarding" that Andersen acknowledges will be necessary if he is to adopt some of Google's practices successfully in his lab upon upon his return. Pair programming takes practice and time, too, like most new skills.
I have seen the benefit of pair programming in an academic setting myself. Back when I used to teach our introductory course to freshmen, I had students pair every week in the closed lab sessions. We had thirty students in each section, but only fifteen computers in our lab. I paired students in a rotating fashion, so that over the course of fifteen weeks each student programmed with fifteen different classmates. We didn't use a full-on "pure" XP-style of pairing, but what we did was consistent with the way XP encourages pair programming.
This was a good first step for students. They got to know each other well and learned from one another. The better students often helped their partners in the way senior developers can help junior developers progress. In almost all cases, students helped each other find and fix errors. Even though later courses in the curriculum did not follow up with more pair programming, I saw benefits in later courses, in the way students interacted in the lab and in class.
I taught intro again a couple of falls ago after a long time away. Our lab has twenty-eight machines now, so I was not forced to use pair programming in my labs. I got lazy and let them work solo, with cross-talk. In the end, I regretted it. The students relied on me a lot more to help them find errors in their code, and they tended to work in the same insulated cliques throughout the semester. I don't think the group progressed as much as programmers, either, even though some individuals turned out fine.
A first-year intro lab is a very different setting than a research lab full of doctoral students. However, if freshmen can learn to pair program, I think grad students can, too.
Pair programming is more of a social change than a technical change, and that creates different issues than, say, automated testing and style checking. But it's not so different from the kind of change that capricious adherence to style guidelines or other kinds of code review impose on our individuality.
Are we computer scientists so maladjusted socially that we can't -- or can't be bothered -- to learn the new behaviors we need to program successfully in pairs? In my experience, no.
Like Andersen, I'm not advocating that anyone require pair programming in a lab. But: If you think that the benefits of pair programming exceed the cost, then I encourage you to consider having your research students or even your undergrads use it. Don't shy away because someone else thinks it can't work. Why deprive your students of the benefits?
The bottom line is this. Pair programming is a skill to be learned, like many others we teach our students.