2016-09-23

Ubuntu 16.04 guest + VirtualBox 5 + Windows: major version coordination bugs

Trying to run the latest Lubuntu (and I presume Ubuntu) 16.04 as the guest within a recent VirtualBox version (e.g. 5.0.22) on a Windows 7 host with anti-virus installed requires a certain amount of ... version coordination dancing, because of a series of unfortunate bugs.

The main problem is that the recent VirtualBox 5.x series has some major compatibility problems with Windows and/or the anti-virus installed with it.  Launching a VirtualBox image could result in a pretty scary error message like:
Error relaunching VirtualBox VM process: 5
Command line: ...............
(rc=-104)
And it's a "hard" error, blocking the VirtualBox image from even attempting to boot the guest OS.  Apparently it's something to do with "Hardened Security" [1].  There's some proposed workarounds but none of the proposed solutions worked for me.

Worse yet, after installation of VirtualBox 5.x (on a Windows 7 host) and successfully testing my Lubuntu guest image, my TrendMicro anti-virus updated overnight which created the above "Hardened Security" problem --- literally overnight!

The only reliable workaround is to downgrade VirtualBox back to the version 4.3.x series.  That's a workaround for the VirtualBox "Hardened Security" problem, but it creates new version compatibility problems between the guest OS and VirtualBox...  argh

But I found working workarounds.

2016-09-15

VeraCrypt: how to verify its GPG signature

(Update:  the following is still correct, but the fingerprint keys I noted have changed after they released version 1.22.  See my recent update.)

I'm not sure why the steps to verify a VeraCrypt download isn't more prominently displayed on their website, so I pieced it together myself here:

Downloaded latest stable release and PGP signature here:
https://veracrypt.codeplex.com/wikipage?title=Downloads

On a Mac, make sure Homebrew is installed (or else you can install these yourself from source).

brew install gnupg
brew install gpg2

Get VeraCrypt PGP key ID from:
https://www.idrix.fr/Root/content/category/7/32/60/

In the terminal, run the following with the VeraCrypt PGP Key ID you got above:

gpg --recv-keys 0x54DDD393
gpg --fingerprint 0x54DDD393

That should display the key fingerprint, which you should compare with the key fingerprint that's posted on:
https://www.idrix.fr/Root/content/category/7/32/60/
and on:
https://veracrypt.codeplex.com/

Now to verify your download, run the following in Terminal for your downloaded version of the files:


gpg --verify VeraCrypt_1.18.dmg{.sig*,}


The message displayed should say the signature used key ID 54DDD393 (make sure it's the key ID found from above!) and is good and from VeraCrypt Team .

Similar instructions apply for Linux, but install GnuPG and GPG from your system's package management system instead.

Similarly for Windows, but you'll have to figure out how to install GPG yourself --- see the Tor project's manual on doing that (that's what helped me piece together the above):
https://www.torproject.org/docs/verifying-signatures.html.en


After all was written above and done, I found VeraCrypt's instructions hidden away at the bottom of a page without mention of what to install and such, but here it is anyway:
https://veracrypt.codeplex.com/wikipage?title=Digital%20Signatures

2016-09-06

Different Types of Learning Tasks and Content Delivery Styles

The following lists a number of learning tasks students may engage in by teacher instruction, and thus they are instruments of teaching a teacher may employ.  Notes regarding each are provided briefly to highlight a range of possible tools teachers may use to engage students in learning.  These are arranged generally speaking from easiest to most difficult to employ effectively.

Every single one of these types of tasks and styles has its rightful place in a course --- there is no magic bullet solution.  Exclusive use of any single style or type of task is not necessarily a good thing as there are always trade-offs to be made.  This list is not meant to be a complete or exhaustive listing of all possible learning tasks or their categorization or description, but a way of thinking about them to help create an effective mixture of learning tasks for any course of learning.

Lectures
- teacher-oriented learning task
- active instrument
- students may remain largely passive for task completion, and can passively wait it out

Theory and verbal/textual explanations are delivered by an instructor to students (focuses on "telling" over "showing").  The delivery is often best done scripted and in an organized manner, almost like a audio/visual version of a printed book delivery of theory or textual explanations.  This term describes a type of teacher-oriented activity.

2016-09-01

New angle on math education: lessons from product design

Or a user interface for learning math

High school is when many students typically first encounter some of the greatest difficulties in learning what forms the basis for learning post-secondary level math. Those are, therefore, some very critical years in a student's math educational career. If it is important to get more students to consider entering a STEM career (and I'd argue it is [1]), then it is important to consider how math can be taught to these students so they'd be more interested in it, and be better at it later on.

The following is a long piece discussing the problems facing designing a better math educational experience, complete with the principles of design that can be used to solve such problems, closing with some guidelines for how to create a better course.  In principle, all of the following can apply equally well to other subjects, like computing science, or English, but math education is tough, so I’m picking on the hardest as an example.

Math course as a product

Just how do students experience of learning math get formed? Rather than looking at it in a traditional teacher's mindset, let's look at it in terms of a commercial product designer's mindset. That means we see students as interacting with a complete, full-fledged math education product that promises students that they'd get what they want.