SLOP-py research from the Flipped Learning Network via

The  Flipped Learning Network wants you to flip. An info-graphic, touted on their homepage, is data collected from their survey’s preliminary results.  The survey is ongoing so go ahead and take it here.

Soft, anecdotal data or hard research?

Something didn’t sit right with me when I took it, so I stopped.  The questionnaire seemed legitimate but my cynical side said, “Statistics can conceal as well as reveal.” So let’s examine why this survey is faulty.

These days I’m guided by best practices that have statistical significance grounded in research. As a result I’m looking for hard data on student achievement as it relates to the flipped classroom. I want to know if this strategy makes a significant impact on learning. The survey didn’t deliver because it is what it is–a survey, not a study.  But there’s a bigger problem with this survey, conducted in partnership with It’s a self-selected survey which raises many red flags. I wanted to learn more so I asked my friend Joan, a market research and statistics expert, for her insight.

“Self-selected opinion polls go by the acronym SLOP, and it’s probably not a coincidence. Self-selection creates a biased sample, so the results of surveys that rely on the participation of self-selected respondents cannot be used to draw conclusions about the overall population.”

That makes sense. The sample consists of  flipped classroom teachers who have discovered the survey on a site that promotes flipped learning. Frequent visitors to the Flipped Learning Network may have had a favorable flipped experience, choose to opt into into the survey, and create a biased sample.  Teachers having a negative experience would be less likely to visit the site and take the survey.

Let’s look further and examine not the Flipped Learning survey specifically, but’s  crowd-sourced, Yelp-style approach of collecting data. I like the idea of teachers providing input. What’s wrong with that?

“I visited the web site, and found that I could sign up to take a survey, and the only controls they have over determining whether or not I am a teacher is a box that I am supposed to check off attesting to that fact.

I not only can choose to participate, I can pretend I’m a flipper.

Let’s say this site was going to survey the effectiveness of a new textbook I have written. I could have asked everyone of my Facebook friends (and only 4 or 5 are teachers) to fill that survey out positively for me, and to repost the request on their pages. This site doesn’t appear to have any controls to prevent that. So not only are they getting a biased sample, they may not even really be sampling actual teachers.”

OK. But let’s say only teachers respond. What’s wrong with that?

“Since these surveys are taken by self-selected respondents, statistically you can’t project ANY conclusions from the surveys to the general population of teachers–you need a random sample of teachers to be able to do that. If they aren’t using a randomized sample of teachers of sufficient size for their surveys, none of their survey results have statistical significance.”

Give me an example.

“Maybe the site draws the attention of teachers that are very enthusiastic about teaching, and they want to provide lots of feedback about everything in their classroom. They may report significant gains using a particular curriculum, and they may indeed have gains – but it might be attributable to their enthusiasm rather than the curriculum.”

Sounds like what I described earlier. If nearly all respondents are enthusiastic about flipping the classroom, we never hear from the dissatisfied flippers because they don’t complete the survey, plus any reported gains may be attributable to the teachers’ enthusiasm. What else?

“Say 1% of teachers visit this site to take a survey on a particular curriculum with which they are dissatisfied and want to see changed. The other 99% of teachers are happy with the program, and don’t even think about providing feedback because they don’t see a need for any corrections. That survey would give very negative results for a program that is essentially quite well accepted.”

What’s your opinion of’s idea of selling its research to school districts and education vendors? If they are looking for teacher input, this is a way to provide it.

“If the surveys have room for lots of comments, they could work a little like a focus group. The comments may be of interest to people that are looking for feedback on a product, although, again, the comments would not be statistically significant, either.

You’ve never been one to mince words, so give it to me straight.

If I were an author/company trying to get a better understanding for how the education market was responding to my book/product, and this site were to approach me about conducting one of these surveys, I would pay them zero dollars for their research. If I were a school district considering a variety of new curricula, and this site offered to sell me their survey results to use as an evaluation tool, I’d pay them zero dollars for their results. If I were a teacher, I’d perhaps be interested in reading some of the teachers’ comments, but since the comments could possibly be written by the marketing team for the product I am considering, I think I’d rather solicit opinions in the faculty lounge.”

Flipping may have a statistically significant impact on student achievement but that conclusion cannot be drawn by SLOP-py research. I cannot advise you to flip or not to flip.

Neither can the survey.

Developing critical thinking using number sense and estimation

Check out Andrew Stadel’s Estimation 180 site. It’s a gold mine for daily number sense. Plus, it’s given me an idea about how to develop math tasks. First, a snapshot of Estimation 180, followed by incorporating the art of estimation when designing a major task.

Students guessed, argued, and revised their estimates before revealing the answer.

Students record their guesses on the number of almonds in a quarter cup. Before revealing the answer they argued with their tablemates why they thought their answer was the closest. It was interesting listening to the arguments. Some took a wild guess; others looked at the context clues. Before revealing the answer, we discussed the context clues as a class–the quarter cup, the size of one almond, the number of almonds we can actually count, the tile countertop, etc. I gave the kids a few minutes to revise their estimate before revealing the answer. Having the kids guess invests them in the problem. The delay of revealing the answer by having the students argue and revise forces them to reflect. It also added drama!

I love the hook and the potential for reflection so much I wove it into the Super Storm Sandy volume task. Before delving into the problem the students first guess the number of dumpsters that are needed to clear away sand from a vacation home. When the first part of the task is completed they compare their solution to their guess then describe what was learned or what was confirmed. Reflecting on their guess and comparing it to their solution helps them to become better critical thinkers and problem solvers.

Superstorm Sandy hits Cape May, NJ.

Dan Meyer’s Three Act Math Tasks also use guessing to hook the students. I would love to turn the Super Storm Sandy volume task into a video format. For now I’ll settle for still photos.

Diary of a mad math teacher! Or, a day in the life


Ohhh I don’t want to get out of bed. I’m thinking about the day ahead. There’ll be fewer 6th graders in each class– they’re on an orchestra field trip. I walk the dog while listening to the Planet Money segment on NPR. Did you know that for 70 years Coke only cost only a nickel?


First period. Language Arts- We’re reviewing word choice by focusing on dialogue tags. How many ways can you say said or asked?


Advanced Math. My B day block is off to the computer lab to take an online survey. It’s to measure student involvement in sports and clubs, their stress levels, bullying, etc. When we get back to the classroom the students share where they’re at with their group video project. We review fraction multiplication and cross canceling.


Math lab. Quiet period. Two students come in for help.


Lunch. I ran out of lunch meat so I had to buy a lousy slice of pepperoni pizza. I don’t think our district wellness plan has been communicated to our food service provider. Cookies and giant Pillsbury cinnamon rolls are well positioned—the calories are easily within reach of an 11 year old’s hands.


Standard Math. Another class gets to take the survey. I find myself defining more vocabulary such as “curfew” and “family obligations”. We return to class and I hand back their formative assessments. We review the problems and focus more on trapezoids.


Plan time begins. Meet with a colleague to plan tomorrow’s Science Olympiad meeting.


I head to the copier to run off copies of an NCTM fractions, percents, and unit rate activity based on Dr. Seuss’ “The Lorax”. You can find it in the October 2012 issue of Mathematics Teaching in the Middle School.  (I’ll write about it in a future post.)  It’s back to the classroom to create another formative assessment on trapezoids.


“Mary!” It’s one of my teammates. This quarter she is using weighted grades and has a few questions.


End of the school day for the kids. No one comes in for after school help.


Officially it’s the end of the day. I check my email one last time. Our team leader sent notes from the monthly meeting. Nothing earth shattering. My plans for tomorrow and next week are set. I pack up to go home.


Head out the building.


Stop at the pharmacy for a Rx.


Home. Take the dog for a walk and pick up after her. Thank goodness we still get our daily newspaper delivered in plastic bags.


Reading the paper while listening to NPR. I’m a public media fan. At 6:00 I’ll watch the PBS NewsHour and wait for my husband to get home from work. Leftover meatloaf will be reheated.

Superstorm Sandy volume task

Here’s a Superstorm Sandy volume task we recently created for 6th and 7th grade. We were struck by the disaster as well as this photo of a home in Cape May, New Jersey. We dug deeper to find an satellite view of the lot on Zillow, a real estate website. It provided the lot size which then helped us to create this task:

Superstorm Sandy hits Cape May, NJ.
Satellite view of lot from Zillow

On October 30, 2012 Superstorm Sandy hit Cape May, New Jersey. The storm washed sand from the beach up to nearby homes to a height of 6 ½ ft.

Consider the dimensions of the vacation home and lot, which is a small area of land. If the dumpster can only be filled to a height of 3 feet, how many dumpsters are needed to clear the sand away from the lot?

Images of the home, plus dimensions of the lot, home, and dumpster are included in the task so students can determine the volume of sand surrounding the home.

Since we are using this task to introduce volume, we created three resource cards to help students with their thinking. We are posing such questions and comments as: Did you consider the height of the sand? Is sand in the house? and Think about how much sand would fill a recycle bin; then relate this to how much sand would fill a dumpster.

We also created two extensions based on using a front end loader and a dump truck.

A front end loader approaches a pile of sand. The bucket’s capacity is 108 cubic feet.
The dump truck capacity is 324 cubic feet.
It takes 50 seconds for a front end loader to drive sand into the bucket, dump it into the dump truck, then return the bucket to its starting position.

Extension 1 determines how many “scoops” the front end loader must make. Extension 2 considers  the use of  a dump truck to determine the amount of time it will take to clear away all the sand.

The photos simulate how a front end loader drives into a pile of sand, scoops up a bucket full, unloads it into a dump truck, then returns to its starting position.

What our 8th grade math teachers like about this task is the potential to use higher algebraic reasoning by introducing more front end loaders and dump trucks to the task.

As is, we’re expecting students to do a lot of mathematical thinking with this task.

City Lots fractions task keeps ALL students thinking

Here’s a 7th grade fractions task called City Lots. My colleagues designed it with two great extensions. I differentiated it by creating resource cards plus I modified the directions to challenge students who need it.

The basic task requires students to determine which of four companies owns the most land. They also have to calculate how much land each company owns based on four quadrants.

City Lots task

The activity was a hit with my 6th grade advanced math students. Most groups began with a strategy of cutting out the shapes to find which company owned the most land. While that was an effective strategy, it’s a difficult way to calculate exactly how much land was owned by each company. That’s where the resource cards came in.

Students cut out grey scale shapes to find which company owns the most land.

Then the mathematical conversations shifted from cutting shapes to discussing how the property was divided. I asked probing questions such as, “What’s the minimum number of squares do you see?” Many didn’t see one unit divided into four quadrants.

We’re trying to do much more reading and writing in math class, and this task is another opportunity for students to articulate their mathematical thinking in writing.

Student designs a table to determine which company owns the most land.

In terms of time, I presented the task midway into the block. In those 40 minutes, no groups got to the extensions, four groups successfully completed questions 1 and 2 and the others are not far behind. We’ll get to the extensions the next time I see them. I did not hand out the challenge task but at least I was prepared.

I don’t think I’ll have an opportunity to try the challenge task, but if you do I would love to hear how it goes.