Thursday, 3 July 2014

07:29 – Fourteen months ago, I mentioned that Joe Hester, who lives down the street from us, had been charged with sex offenses against a student in the high school where he taught. This morning’s paper reports the resolution of that case. Mr. Hester was sentenced to a prison term of 7 years and 10 months to 14 years and 5 months and was ordered to register as a sex offender for 30 years following his release. All of that for what I suspect was probably consensual activity with a 15-year-old girl. As Barbara said, the punishment was all out of proportion to the crime. This guy will spend more time in prison than the habitual drunk driver who killed the mother of one of Barbara’s co-workers recently. I don’t know Joe. This all happened very soon after he and his wife bought the house down the street. I’ve only talked with the guy once for a few minutes, and have never done more than shout hello to his wife. But he seemed like a nice enough guy. And now he’s ruined not just his own life, but his wife’s as well.

12:21 – I’ve been dithering for a while about doing an AP Chemistry kit. I’d originally intended to introduce one in 2012, but the College Board had announced that they’d have a completely revised set of AP Chemistry labs in 2013. So I waited on those. I wasn’t happy when I saw what CB had done. They reduced the number of labs and (as far as I’m concerned) dumbed them down considerably.

To do the labs as specified, a homeschooler needs an accurate balance/scale. That’s not a problem. One can buy an electronic scale with 100 or 200 g capacity and centigram (0.01 g) resolution on Amazon for $10. A balance with 20 g capacity and milligram (0.001 g) resolution costs about $20. That’s doable for most homeschoolers. But the new labs also require a visible-light spectrophotometer (or at least a colorimeter) and a pH meter. A pH meter with useful resolution and accuracy runs $100 or more, and even the least expensive standard spectrophotometers start at $500 and go up rapidly from there.

I’d about decided to do a lab kit that covered the new AP Chemistry labs as closely as possible without requiring a lot of expensive equipment, but unfortunately “as closely as possible” wouldn’t have been very close at all. Part of the AP Chemistry lab experience is supposed to be learning to use this type of equipment.

I finally decided to do an AP Chemistry lab kit that uses an inexpensive electronic balance, that $100 pH meter, the $115 Vernier Colorimeter and the $61 Vernier Go!Link interface. The balance and pH meter I already have. I just ordered the Vernier stuff, which should arrive next week. The Vernier colorimeter isn’t a perfect solution. Unlike a true spectrophotometer, which allows varying the wavelength of the light continuously or in very small increments, the colorimeter offers only four discrete wavelengths, but that suffices to teach the important concepts.

I think I can take the balance(s) as a given, but there will be many homeschool parents who do not want to or cannot afford to spend $100 on a pH meter or $176 on the colorimeter and interface. For them, I’ll provide data that I gather myself and that their students can use to graph and analyze as they would if they actually had the instruments. It won’t be the full lab experience, obviously, but it’ll be a lot better than nothing.

I’m also concerned about the dumbing down thing. The truth is that our standard CK01A kit, which we specify as honors first-year chemistry level, is considerably more rigorous than the new AP Chemistry, which is supposedly second-year level. So, I plan to do the AP Chemistry labs as specified, but to fill out the kit manual with additional lab sessions that are actually of appropriate rigor for a second-year chemistry lab course for students who plan to go on to major in STEM at college.