AP Stats at the STEM Expo

I moved up the timing of my statistical inference/experiment design test this spring (usually its the "capstone" project kids do as their final) so that we could participate in our district's STEM Expo tonight. (I think its really just the traditional science fair repackaged, but I'll go with it. LOL)

As I wrote a couple weeks ago, I enlisted the help of a doctoral student from Washington University to give some tips/insight on making and presenting their posters, and we spent the last 5 days of class working on our survey instruments, analyzing the results, and presenting them on a poster.

This is the first time these projects/experiments have ever had an audience beyond myself, so I'm really excited to see my students out in the "real world" talking about statistical inference. I literally had a student email me over the weekend and tell me she would change whatever I asked and do whatever I demanded so her poster could be perfect. You've gotta love that.

The NYU research poster guide and continued support from +Ryan Watkins ended up being a huge help, and after an assist from the CAD teacher downstairs, I'm real excited with how these posters turned out.

I had one student who could not make the Expo, so I had him present last week to our friends at another high school in our district in AP Chem.

There's always something special about seeing kids describe and defend their work that is better than most of the feedback that a teacher could ever give traditionally. They often find errors in their writing, their process, and bits that are confusing or could be more clearly explained as they try to sort out what their work SAYS with what it is actually supposed to be communicating.

We found a few errors in the graphical representations or calculations as we were sharing with parents at the Expo, but I was so thrilled that they found them and corrected the mistakes that I couldn't be anything but proud of them. If you'll notice the poster in the video, he has a lot less going on... he actually only did about half of the work, and I don't know if he noticed it until he got to the end of describing his methods after a couple minutes and didn't really have much to SAY about it - nothing to interpret. There's a verbal pause where (I hope) he realizes he's done, but shouldn't be.

Tip Tuesday - Copy Your Padlets for Other Sections

I love using Padlet as a landing strip for students to share ideas, work, or problems they're creating.

Here's some ways I've used Padlet on my class set of iPads:

• backchannel
• students' summary statements after reading a text
• generating questions before or after reading
• gathering guesses or estimations of an answer during Act 1 of 3 Act Story
• students creating/solving exercises to share with each other
• reflecting on a video or text

Some of those uses listed above might actually be enriched by students being able to go back to earlier periods in the day and see what they did, particularly the backchannel or creating exercises for each other to solve. For the reflections or checks for understanding, I think having other kids' thoughts on there pollutes the experience and prevents new ideas.

For yesterday's work, I wanted my students to make up the graph of a line, write the equation for that line, share their work on the padlet, write the equations of some of their classmates lines, and then have the classmate check them off as correct or needing more work. It wouldn't have been the end of the world if some of the lines got repeated, but it was important that the line creators were in the room so that they could check their peers' work.

In THAT case, where you need a fresh board for each period, you can COPY your padlet with identical settings so that you don't have to duplicate your own work.

I chose "copy with posts" on this occasion because I wanted my own example up there. 

 Another pro tip: edit the addresses of your padlets for easy sharing with the date and hour.

After the day was over, I had 3 padlets that all looked SIMILAR, but were unique to each hour.

For more info, check out the Padlet blog - I checked after the fact, but they wrote a recent post about copying, too.   :)

Does Major League Baseball Need a Stats Lesson?

I saw this data in the St. Louis Post-Dispatch last week claiming that the Cardinals are the 6th most expensive team  to see at their home park. (the "FCI" averages all of the columns from this chart together to get an estimate of what a family of 4 would expect to spend at the ballpark.)

I have no problem with the FCI, but I wonder if this chart's reporting of "MLB LEAGUE AVERAGE" is a little off. That row looked suspiciously in the middle to me, and when I counted rows, it was indeed exactly in the middle.

So what's going on here? Is it a misrepresentation of "average," do MLB teams attempt to group themselves symmetrically around this figure, or is it pure coincidence?

Here's the MEAN of those FCI listings by team:

Could the difference between 211.68 (reported in the table as "average") and my calculation of 211.89 be the result of rounding error in the data they used that I don't have access to in this report? Are there 21 rogue cents floating around in their numbers? 

What's this mean for my students?

I think this graphic and table is a good conversation starter for both mean vs. median AND the role of rounding in getting "different" answers. What's the clue that this CAN'T POSSIBLY be the median? Its not listed in the data of course.