statistics

3 Comments Posted on blogging

You probably Googled this

I’ve had this blog since November of 2012, about three and a half years. WordPress.com very kindly offers me a bunch of interesting statistics, and today I noticed a trend in the “Referrer” area.

There are a bunch of referrers, but the top two are always “Twitter” and “Search Engine”, like this result from May 2015:

Referrer

The Trend

Here are the annual statistics since the blog started:

Year Search Engine Referrals Twitter Referrals
2012 12 53
2013 653 637
2014 5893 1281
2015 (to date) 4056 318

There’s about a 90% chance that you arrived here via search engine.

The Why

First, I don’t tweet out links to old stuff very often. If you followed a Twitter link to get here, it was probably new content. Old stuff is always available by search engine. I think think is the most important reason.

Second, I’m not as active this year as I have some other priorities. I’m not as well connected with the rest of the province. The blog is more intermittent.

Last, a lot of people are searching for my blog, not just “assessment in math” or some other topic. So the search engine referrals are both intentional and incidental visitors.

I find this interesting to think about, although I don’t imagine it’ll change how I do anything.

Leave a comment Posted on education, statistics, teaching

Poor research in education bothers me

When I look at educational research about instructional strategies, I’m concerned with how often the researchers ignore important controls. They confound their data and then draw invalid conclusions.

I just read some research in which students were taught the same math content but using two different approaches:

  • Group A was taught “traditionally”, which included teacher-led, direct instruction;
  • Group B was taught with a student-directed approach and a specific context.

After read the descriptions of the two groups, what conclusions could you draw if one group outperformed the other group?

Unfortunately…

…the researchers concluded that the context they used was important for student learning. They admitted that the specific context required a very different instructional approach, but they attributed the achievement differences to the “theme” of the task.

Confound it

That’s really not good enough. You can’t have two major differences between groups and then point to either difference as the cause. In fact, you can’t conclude much of anything from data like this.

Fail.

Do it right

Only change one thing at a time. If you need to change more, try a third group (here, you can have a group with a student-directed approach but without the contextual restriction). Then you’ll be able to tell if the difference is due to the approach or the approach with the context.

Leave a comment Posted on statistics

Two interesting research ideas

I was chatting with some students yesterday about their names (spelling of last name, origin of first name, etc.) and I thought it would be an interesting study to look at how people get their first names.

For example, one student said she was named after a song that her parents liked. Another’s first name was a family surname.

How do we decide names?

It would be interesting to survey a large number of people and ask about how their parents (or whoever) named them. There might be a correlation to gender, or a trend based on age. I bet it would be fascinating.

Maybe I’ll make a Google Form and ask on Twitter.

I had another thought, which came from a map I saw once showing the locations of tweeters across the globe in real time (I forget the site now). I wondered if certain topics were more likely to be blogged about or tweeted about at certain times of the day because of geographical popularity. For example, I wonder if ukuleles are blogged about more during Hawaii’s evening than other countries’ evenings. Hmm.

2 Comments Posted on education, math

Student questions about probability

After yesterday’s realization that I was directly the flow of learning too much in my class, I asked my students today to generate some questions they were interested in regarding probability. Here are their responses (posted also on the class blog at mrgrasley.wordpress.com).

  1. What are the chances of winning the lottery?
  2. What are the chances of finding a shiny Pokémon?
  3. What are the chances of the earth being destroyed by an asteroid?
  4. What are the odds it will snow tomorrow?
  5. What are the chances of winning a car in Roll Up The Rim?
  6. What are the chances of being “caller number 5” on a radio contest?
  7. What are the chances of your seat being picked for the million-dollar shot at a basketball game?
  8. What are the chances of being struck by lightning?
  9. What are the chances of finding a $100 bill on the ground?
  10. What are the chances of getting all red lights on the way to work?
  11. What is the probability that a solar storm wipes out Earth’s electronics?
  12. What are the odds of an average poker hand winning?

I’m proud of their questions. I can see that some of them will be very difficult to answer, and others fairly easy. All of them will require some thinking about possible outcomes or statistical probability (which we haven’t studied yet, so that’s pretty awesome).

Tomorrow we’re going to start trying to solve these questions. I’ll give the students the list, and we’ll start drumming up solutions in groups using chart paper to record thinking. I’m pretty excited; I hope they are too. There is a ton of excellent learning that can come out of this.