Apparently EditGrid let their domain name (editgrid.com) expire, and at present, anyone using their excellent shared spreadsheets is without access to them. What gets returned when someone currently visits www.EditGrid.com has been a 403, a parking page, and a 404 in the past 24 hours.

This morning, I did some sleuthing and found the working IP address of the www.editgrid.com web site. I have regained access to my spreadsheets by adding this little tidbit to my /etc/hosts file: www.editgrid.com


Measures of Effective Teaching


Of the 36 items included in the Gates Foundation study, the five that most correlated with student learning were very straightforward:

  1. Students in this class treat the teacher with respect.
  2. My classmates behave the way my teacher wants them to.
  3. Our class stays busy and doesn’t waste time.
  4. In this class, we learn a lot almost every day.
  5. In this class, we learn to correct our mistakes.

When Ferguson and Kane shared these five statements at conferences, teachers were surprised. They had typically thought it most important to care about kids, but what mattered more, according to the study, was whether teachers had control over the classroom and made it a challenging place to be. As most of us remember from our own school days, those two conditions did not always coexist: some teachers had high levels of control, but low levels of rigor.

From the Atlantic article, Why Kids Should Grade Teachers.

Money Mischief, By Milton Friedman

In the first chapter Friedman compares using gold as the basis for money to using stone discs:

For a century and more, the civilized world regarded as a concrete manifestation of its wealth a metal dug from deep in the ground, refined at great labor, transported great distances, and buried again in elaborate vaults deep in the ground. Is this one practice really more rational than the other?

Then he spends all but the final chapter detailing the pain and suffering inflicted upon societies using silver or bi-metal standards. I felt like much of the data (some in works with no citations) was cherry picked or tortured to fit his conclusions. If his conclusions are sound, and the evidence is so clear, then why does he need to work so hard to prove them? I nearly gave up the book. But the the last chapter turned out to be quite good, containing this little pearl:

It is natural for individuals to generalize from their personal experience, to believe that what is true for them is true for the community. I believe that that confusion is at the bottom the most widely held economic fallacies-whether about money or as an example just discussed, or about other economic or social phenomena.

The first and last chapters of the book are good. I think that only economists that drink from the same Kool-aid pitcher as Milton Friedman will enjoy the rest of the book.

Mobile phones in Costa Rica

To use an iPhone in Costa Rica, one must have an unlocked phone. When we travelled in February, my iPhone 4S was not yet unlocked so I took a jailbroken and ¬†unlocked iPhone 3. When we arrived, I dropped in a prepaid Kolbi SIM, set the data APN to ‘kolbi3g‘ and was off and running. I found the APN on the flexispy list. I used the TetherMe app to share the 3G connection with my iPad.

During the two weeks trip, I had only one issue when my phone stopped working. I just needed to reboot the phone and unlock the SIM. Besides an iPhone 3 being slow, everything worked flawlessly for the rest of the trip.

Notes to self:

  • do bring along the bluetooth iPad keyboard
  • February is the right time to go. The change from soggy grey Seattle days is welcome, and the 9 Seatte residents we met in C.R. agreed.

Scale is hard: gmail edition

Sometime on or about August 8th, IMAP access to Gmail stopped working for me. I don’t depend on Gmail so I ignored the error messages for 6 days. Then¬†I simulated an IMAP session and was able to authenticate to Gmail, but after that, all IMAP commands timed out. So I looked to the Google Apps Dashboard¬†which reported that everything was fine. Lies. Then I found the Gmail Known Issues page¬†where I found this:

We are aware of an issue where users are receiving an error that ‘”imap.gmail.com” is not responding’ when using IMAP on their computers, mobile devices, or tablets. We are currently working on resolving this issue.

In the meantime, you can sign in to Gmail through a web browser. For Android and iOS users, you can also download the Gmail application in the interim.

Then I found the Gmail Forum within the Google Product Forums where many other users were reporting this issue. What I find interesting about this failure was that it took 7 days before my account access was restored and many users are still affected, 9 days later.


Lucas is growing up

Today we rode our bikes to school. This was the first time this (calendar) year, and the weather made riding irresistible.

Lucas decided he was going to ride his new big bike (16″ wheels) instead of the Trail-A-Bike with me. We left a little early, just in case. We didn’t need to. Not only did Lucas keep up just fine, but Kayla couldn’t catch him. One whiff of her catching up and off he zoomed. After riding back home (2 mile round trip), we had to travel 8 blocks out of our way, because it has been too long since we biked past the church.

Two weeks ago, he picked out his own books from the library, and is able to read half of them. He starts kindergarten in the fall. He is more than ready.

ZFS: Z pretty File System

This week I had two disks fail. The first was the cheapest to fix, as it was in my 27″ iMac. I took the entire machine to the Apple Store and picked it up the next day. The failed disk was covered under AppleCare, restoring my data from Time Machine backups was effortless, and my total cost was $4 in gas and 1 hour of time.

The other failed disk was in my file server. The server had a mirrored pair of 1.5TB disks and a mirrored pair of 1.0TB disks. One of the latter exhibited pre-fail symptoms so I ordered a pair of 3TB disks to replace both pairs.

I removed one disk from each existing pair, inserted my new disks, created the new zpool, and then remembered why I like ZFS so much. Here are the commands required to initialize the new disks and copy everything to the new array:

zpool create zmirror3 mirror ada1 ada2
zfs snapshot -r tank@now
zfs send -Rv tank@now | zfs receive -Fvu zmirror3

That’s it. There’s a little housekeeping, like setting ‘zfs set mountpoint=none’ to prevent conflicts and cleaning up the snapshots, but that’s really it. By using ‘zfs send -R’, all the zfs pool and volume meta data gets transferred too. It seems too good to be true. Below are the verbose messages that are enabled with the -v flags included above.

receiving full stream of tank@now into zmirror3@now
receiving full stream of tank/root@now into zmirror3/root@now
received 1.31GB stream in 20 seconds (67.2MB/sec)
receiving full stream of tank/usr@now into zmirror3/usr@now
received 1007GB stream in 8625 seconds (120MB/sec)
receiving full stream of tank/snapshots@now into zmirror3/snapshots@now
received 456GB stream in 7487 seconds (62.4MB/sec)
receiving full stream of tank/swap@now into zmirror3/swap@now
received 34.6MB stream in 4 seconds (8.66MB/sec)
receiving full stream of tank/var@now into zmirror3/var@now
received 1.10GB stream in 34 seconds (33.2MB/sec)

How much do you need to retire?

Here is a simple paradigm (from a comment BenE posted) for quantifying how much a person needs to retire successfully*:

Divide your life into three thirty year periods. During our first 30 years, we have limited means for savings. During the next 30 years, we work and save. We spend the last 30 years retired, spending our savings.

To spend as much in retirement as we did during our working years, we must save half of our income during our 30 working years so that we may spend that half during our 30 years of retirement.

Read that again. Pause and reflect on that.


There’s plenty of factors that influence how much one must save. This paradigm excludes them so that the raw scale of savings can be easily grasped. Some of the most notable factors that can influence how much it is necessary to save include:

  • Start saving early
  • Postpone retirement
  • Social Security income
  • drastic reductions in living standards
  • Be born to rich parents/win lottery
  • Die early
  • Retire at the beginning of a long bull market.

* Successful retirement is defined as not outliving ones nest egg, or as not having to eat Alpo in ones golden years (William Bernstein).