Sciences: what is a cross-sectional study?

Tutoring science, you might encounter experimental design. The tutor mentions the idea of a cross-sectional study.

cross-sectional study:

Let’s imagine a characteristic of interest, C.

In its simplest form, a cross-sectional study will select two groups – group A with characteristic C, and group B without it. Then, the investigators will measure other characteristics of the groups, wondering if the presence or absence of the others is connected with the lack or presence of C.

Except for the absence or presence of C, the members of groups A and B will be similar.


Carlson, Neil R. Discovering Psychology. Needham Heights: Allyn and Bacon, 1988.

Jack of Oracle Tutoring by Jack and Diane, Campbell River, BC.

Canadian culture: Jane Siberry: One More Colour

Self-tutoring about Canadian culture: the tutor reflects on a memorable Canadian 80s hit.

Jane Siberry is a Canadian music artist. Perhaps she began in ’81 or before, but I know of her because of a single hit from the 1980s: “One More Colour” from her 1985 album The Speckless Sky.

I remember hearing “One More Colour” when I was fifteen. It called me back to a childhood that I’d glimpsed, but was losing. Its lyrics hint at life in Canada:

A basket of apples by the back door, beneath the sweater pegs
The autumn leaves lift along the street….

-Jane Siberry, “One More Colour”

“One More Colour”‘s dreamy, bouncy melody draws the listener into contemplation. It’s catchy, yet intriguing – I can’t think of a similar song. Underneath, Jane starts by asking, “Is it lasting?”

“One More Colour”‘s meaning seems difficult for me to decode, while its tone seems to ask, “Why worry?” It’s mysterious, yet somehow reassuring.

I can’t recall any of my friends mentioning “One More Colour”, yet I saw the video on TV. Truly, I think it’s catchier than some 80s hits that receive more attention.

That part of my life passed quickly, but I never forgot “One More Colour”, half of whose video I caught on my way out to catch the bus when I was a kid of fifteen. I knew I must, eventually, listen to the whole song. Now, thanks to the internet, you can, too:)



Jack of Oracle Tutoring by Jack and Diane, Campbell River, BC.

Health: mistaking thirst for hunger

Self-tutoring about cues: the tutor looks into possible confusion between hunger and thirst.

Apparently, feeling thirsty but thinking it means hunger, really happens.

The advice I’ve read to prevent hazard from the confusion:

  1. Drink water throughout the day. Then, you might not develop thirst, since you’ll prevent it.

  2. If you feel hungry, but haven’t drunk water in a while, drink some water first, then wait. If the hunger persists, and you indeed know you’re awhile since eating, likely you really are hungry.



Jack of Oracle Tutoring by Jack and Diane, Campbell River, BC.

Biology: final products of fat digestion

Tutoring Biology 12, digestion is covered. The tutor mentions the products of fat digestion.

Dietary fat is finally digested into glycerol and fatty acids, which can enter the absorptive cells of the small intestine.


Mader, Sylvia S. Inquiry into Life, 9th ed. Toronto: McGraw-Hill, 2000.

Jack of Oracle Tutoring by Jack and Diane, Campbell River, BC.

Nutrition: glycemic index of vegetable oil

Self-tutoring about glycemic index: the tutor mentions the glycemic index of vegetable oil.

Since it doesn’t contain carbohydrate, the glycemic index of vegetable oil is zero.


Jack of Oracle Tutoring by Jack and Diane, Campbell River, BC.

Tree identification: sweetgum, part II

Self-tutoring about local trees: the tutor mentions the sweetgum for the second time.

Back on September 15, 2015, I noted a sweetgum tree in Campbell River. Its star-shaped leaves were how I identified it.

Yesterday, I saw one without leaves and didn’t recognize it as a sweetgum. After some research I discovered its numerous spiky fruits, still present after its leaves have fallen, tell that it is, indeed, a sweetgum. This one isn’t big like others I’ve seen, but seems prosperous enough, given the many dozens of fruit hanging from it. I saw it down in Parksville.


4-H Forest Resources

Jack of Oracle Tutoring by Jack and Diane, Campbell River, BC.

Lifestyle: Parksville

Self-tutoring about traveling on Vancouver Island: the tutor comments on his stay in Parksville.

Parksville has given me a wonderful week.

I find the people here friendly and considerate. Last night, I was crossing at a corner. Someone was waiting behind me to make a left turn. They did not enter the intersection until I was on the sidewalk at the other side. Such politeness might be surprising, but not in Parksville.

Wherever I go here, the people I meet say “Hello” and wish me a good day.

The other night, walking home, I saw a business all lit up as if it were open. Yet I was sure it wasn’t, given the lateness of the hour. I looked inside. Two men were playing a board game after closing up shop. Making hand gestures, they were absorbed in conversation as they set up the game. It might have been a sight from another era…unless you’re here.

Everywhere in Parksville, the people have buoyed me during a very busy week. It will be tempting to return here….

Jack of Oracle Tutoring by Jack and Diane, Campbell River, BC.

Health: a hot shower might make you feel better, but why?

Self-tutoring about the habit of showering twice a day: the tutor wonders if it brings more benefits than cleanliness.

A hot shower can seem surprisingly rejuvenating, but does it bring real change to body chemistry? Perhaps yes.

Apparently, a hot shower can promote oxytocin release in the body. One of oxytocin’s effects is to relieve anxiety.

Believe it or not, a hot shower can also cause the release of growth hormone, which promotes healing.

Apparently, a hot shower likely has true biochemical effects.


Jack of Oracle Tutoring by Jack and Diane, Campbell River, BC.

Nature: nightcrawlers, part 0

Self-tutoring about worms: the tutor mentions a sighting.

I’m in Parksville this week. The other night I had to go out for a razor because I forgot mine at home. It had been a rainy, windy day. Luckily I went out during a lull, walking around a kilometre.

The roads and sidewalks were wet. After a while I walked over what I first thought to be a stick.

“That was a worm,” I thought to myself.

“No,” I continued. “It’s much too big to be a worm.”

“Go back. You’ll see.”

Retracing a few steps, I did see: it was a worm. Believe it or not, I think it was ten inches long.

During the walk I encountered a couple more that were a little smaller, but another one the same size as the first. I’ve never seen worms that big in Campbell River.


Jack of Oracle Tutoring by Jack and Diane, Campbell River, BC.

Networks: when one remembers you but it’s changed

Self-tutoring about computer skills: the tutor tells about logging onto a network whose password has changed.

What follows is how I remember the situation. For anyone facing it, the idea might be helpful.

I was trying to get online with a network the laptop has been on before, but whose password has changed. I wondered what the laptop would do.

After a couple of minutes (it seemed a long time), the laptop came back with a message that it couldn’t log on to the network. It didn’t tell why, just that it couldn’t.

I tried again, hoping that it would ask for the new password, but it didn’t. It just said, once again, that it couldn’t log on.

I went to the list of networks and selected the one I was trying to get on. Then, instead of clicking Connect, I clicked Cancel.

I returned to the list of networks, selecting the one I’d just cancelled. Since I’d cancelled it (I’m guessing), the computer treated it as a fresh network, so of course prompted me for the password, which I gave and got online. All good.


Jack of Oracle Tutoring by Jack and Diane, Campbell River, BC.