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frugal technology, simple living and guerrilla large-appliance repair

Regular blog here, 'microblog' there

Many of my traditional blog post live on this site, but a great majority of my social-style posts can be found on my much-busier microbloging site at updates.passthejoe.net. It's busier because my BlogPoster "microblogging" script generates short, Twitter-style posts from the Linux or Windows (or anywhere you can run Ruby with too many Gems) command line, uploads them to the web server and send them out on my Twitter and Mastodon feeds.

I used to post to this blog via scripts and Unix/Linux utilities (curl and Unison) that helped me mirror the files locally and on the server. Since this site recently moved hosts, none of that is set up. I'm just using SFTP and SSH to write posts and manage the site.

Disqus comments are not live just yet because I'm not sure about what I'm going to do for the domain on this site. I'll probably restore the old domain at first just to have some continuity, but for now I like using the "free" domain from this site's new host, NearlyFreeSpeech.net.

Sat, 12 Jan 2019

My article on SICP and HtDP was linked on Hacker News, and here's what I said in the comment thread

I went to Hacker News, as I do, and I found an article I wrote some time ago linked in the feed.

In case you need to know more before you click, here is the title of my original article on the books Structure and Interpretation of Computer Programs and How to Design Programs: If not SICP, then what? Maybe HTDP?.

The Hacker News link prompted a very long discussion.

Here is what I wrote in that thread:

I'm the author of the original blog post, and I wanted to say that SICP, as well as HtDP, and even a book like Robert Sedgewick's Computer Science (https://www.amazon.com/Computer-Science-Interdisciplinary-Robert-Sedgewick/dp/0134076427/). are in a completely different category than more mainstream how-to-program books (like anything from O'Reilly, Manning, No Starch, Pragmatic Programmers) and even the other popular college texts like Y. Daniel Liang's Introduction to Java Programming and Data Structures (https://www.amazon.com/Introduction-Programming-Structures-Comprehensive-Version/dp/0134670949/) or the book in my intro class, Tony Gaddis' Starting Out with C++: Early Objects (https://www.amazon.com/Starting-Out-Early-Objects-9th/dp/0134400240/).

Supposedly all of these books assume (or at least allow for) no background in programming, but I think the reality is that taking SICP or even HtDP into the intro class at a non-elite university or a community college would be a complete non-starter and/or abject failure.

What I'm trying to say is that there is a place for both of these approaches: A deep look into computer science, and the nuts and bolts of basic "get it done" programming.

Should both of these things happen in a single class, or series of classes? I think the answer is yes. But how to do that and not leave non-elite students back on the road is another matter.

I believe that the HtDP authors think that the "domain-specific knowledge" required of SICP was a barrier.

And I also understand how advanced CS students think that a class focused on how to manipulate strings, use loops, deal with variables of various types, and work with basic logic in the context of a specific computer language is NOT computer science.

But in my view, most students -- and all average students -- need to crawl quite a way, then walk, before they can run.

Even Sedgewick's Computer Science, which focuses on Java and has a wealth of great questions/assignments all along the way, could really be a barrier to students who aren't steeped in math and science. I learned some math while going through the book, but I didn't learn so much programming. Liang's approach might be too basic for someone who has already done years and years of programming but is way more approachable for those who have not.

My guess is that many professors tried SICP and had a very poor rate of success. I fully support a selective class that says, "this is very hard, but you will learn a lot and look at the world in a different way, and if you really want to understand computer science, this is the class for you."

But there also needs to be more of a gateway class for future programmers (not necessarily graduate-school-bound CS majors) that eases them into the world of writing code. Offering the basics and sneaking in some CS seems better than doing it the other way around.

In a way, it's like the difference between carpentry and architecture. You can teach people who want to build houses how to design them, but at some point they're going to have to get out a saw, hammer and nails and make something happen.


What I'm trying to get at here is the idea that computer programming and computer science are different things taught in different ways. It's possible and probably advantageous to teach both at once, but there's quite a devil in those particular details, and nobody seems to be happy with how it's done. The CS-first, math-problems-out-front approach has the potential to alienate non-elite students and should probably be restricted to those who know what they're getting into.