Feb 202016
 

As I have been examining my practice through the lens of Critical Theory, I asked myself how would I teach differently now than I did even a year ago? Great question.

If-you-change-the-way__quotes-by-Wayne-Dyer-40  It is time for me to look at AP Stats differently.

The last year I taught AP Statistics, I created great connections through the entire year on each topic, how each piece fit together, and how the end results started from the beginning topics. I carefully planned it so that every element of the year connected. And then, after the AP Exam, we had 4 weeks where I challenged the learners to come up with a question, do the research, and answer the question. Topics ranged from bullying, treatment of gays in stores, to trash on the side of the road. A huge, broad range of topics.

But, we did not do anything about those topics. We didn’t share them with the community. We didn’t have time. We collected great information, but we did not ACT on it.

If I teach it again, the first week is answering the following questions.

  1. What problem in our community do you wish to solve?
  2. Is this problem something on which we can we collect data?
  3. What data do we need to collect before we can formulate a solution?
  4. Share with class.
  5. Are there any similarities in problems?
  6. Can we consolidate any of the ideas?
  7. Discuss.
  8. Revisit 1 – 7 until we can not do 6 any further.
  9. List the topics for the class.
  10. Form groups for each topic based on your own interest and your own passion.

After that first week process is over I would think we have between 2 and 7 different projects in each section. I would have to be flexible and let the class drive the number and type of projects. The only thing I can think of why to reject a project is if we would have to deal with FERPA violations, incredibly sensitive topics like rape or incest, or other legally sensitive issues.

This is the truly difficult part of the teacher’s role, is playing the gatekeeper. I would want the learners to make decisions on what they want to study, but I know that there are some topics that are not researchable by high school learners. We don’t have an IRB to do experiments on people, for example. But we want some groups to do experiments. So I would need a committee of people at the school willing to be the final Yes / No on some topics. This is actually true to the real practice of research.

After we have decided on the specific topics, then we start into the process of answering the following questions:

  1. What types of data are there in your question?
  2. How do we display those types of data?
  3. How do we collect the data in the most scientific manner?
  4. etc, etc, etc.

These are questions that come out of the AP curriculum word for word. The only difference is that I, as the teacher, will be phrasing the lessons in the context of their projects. We will be learning from the different groups why we need to know about categorical and quantitative data. We will be learning from the different groups why bar graphs work for one type, but not for another type, and we will have to dive deeply into cluster, stratified and every other type of sampling in order to come up with the BEST way of collecting data for each project.

The goal now is to dive into the AP Stats curriculum deeply. We won’t need to come up for air because we will be inhaling the vapors of our excitement for our project. (wow, that metaphor was tortured, wasn’t it?)

  • What if a learner wants to switch? I don’t think there is a problem with that. Let them choose their enthusiasm.
  • What if an entire group decides they are more passionate about different other projects? Great, then we dissolve that research group and form a new one.
  • What if they decide to start over with a new question 1/2 way through the year? If they really want to go backwards, and redo all the work they have done on experimental design, research design, question creating, data analysis, and all of the rest of the topics then why stop them from relearning the material in a different context? Granted it is a ton of work, but they are learning, relearning, and taking charge of their education on a topic they are interested in. Why block them artificially?

Second semester is about finishing probability so the learners can moving into confidence intervals and tests. This is where the decision making comes into play, and as the learners become confident in this area, they will be making decisions on their topics.

Those last four weeks of school when I used to do projects would now be turned into “Action.”

  • Meet with the administration or counselors of the school about the data collected and share the statistics and conclusions. Work with the them to come up with a plan to solve problems, or at least come up with a plan to work on solving problems.
  • Write letters to the newspapers and media.
  • Write letters and meet with politicians.

The end goal is to allow the learners to drive the content of the class. They would be much more engaged in their own questions than any question I could come up with.

They would still be learning 100% of the AP Statistics curriculum, but now they would be more engaged and see the purpose for each “module” of the curriculum in a more solid, substantial way. This should help with AP scores (but I have no data to support this).

And in the end, hopefully it would make the community (however the learners bounded this) better.

What it would take from me is a huge willingness to give the learners power over their own education. They would have the ability to make decisions, and be allowed to follow through on those decisions. Some of those decisions will not turn out with positive (statistically speaking) results. They will get negative results. That is real life.

It would take time to plan, to organize content around their projects, and to think deeper about the connections. It would take time to connect with admin and parents to explain why I am doing this. It would require the admin of the school to be willing to allow learners to have the power.

It would absolutely weaken the oppression of the learners done by curriculum designers.

I want to do this. I am not in a classroom any more to do it.

Is anyone willing to partner? I will help. I will support. I will do everything in my power to make your life easier while doing this.

I think it is worth doing.

Jun 082015
 

My learners have been using Plot.ly for a week, and have asked me a ton of questions on how to do certain things with their data. I wanted to add details to my last post on Plot.ly v. JMP and tell you the decision I made regarding the issue. All of the questions I have below are actual questions / issues  my learners ran into using Plot.ly.

Issue 1. How to add % totals to the columns of data in a graph?

One group of learners had a beautiful graph made in Plot.ly. It was nice, communicated well, but had lots of information in it. They wanted to put the % of each column in the graph to make it more informative.

In other words, they had this ……….and wanted this. (the reason for the arrow in a sec)

graph1 graph2

Yes, these are JMP graphs. Why? Because after an hour of looking, I could not find a way to have Plot.ly do it. Their help is silent on this issue, and I looked through a whole bunch of graphs shared on their website and found not a single one to do that.

As far as JMP, it took two clicks. I can’t show the menu because it is a drop down and as I tried to screen cap, it went away. You click the red triangle I pointed to, hover over to “Histogram Options,” and click on “Show percents.” If you want to “Show counts,” you can do that too. One or both! Two clicks. This was incredibly simple to do in JMP, incredibly difficult in Plot.ly.

Issue 2: Chi-Square test

I already dealt with the fact that Plot.ly calls graphs that use categorical information histograms in my last post. This has caused so. much. confusion.

But now my learners are trying to do the statistics for their data and see if there are significant differences in their samples. They are trying to DO statistical inferences. If their data is quantitative, they can do a t-test easily. Well, they can do a two sample t-test easily. They cannot do a one sample t-test or a matched pair t-test. They cannot do a z-test in Plot.ly, and as it turns out, you cannot do a Chi-Square test in Plot.ly unless you already have the summary counts.

Really? I can do the “histogram” to get the counts, but I cannot import those counts into the table to do the Chi-square? It won’t count the instances of words to count them for the test?

For example, if the learners data looks like this:

data1  Plot.ly will do a histogram for it and tell me what percent or what counts there are for Gender and AP/Honors.

If I want a Chi-Square test for these two columns, the only way I could make it work was to look at the graph of counts, write down the information into a two-way table, and enter the counts as a matrix in the graphing calculator.

To do the same thing in JMP, we do the following steps:

1.  Go to Analyze, Fit y by x JMP1

 

2. Click on OK. That’s it. The output contains the following:

JMP2  A mosaic plot of the graph which is nothing more than a stacked bar chart, except the width of each column is proportional to the total number of things in the column.

Next, we get the contingency table. If I click the red triangle, I can choose other values to include or exclude from the table.

Finally, the Chi-Square test p-value.

That was around 6 clicks, instead of making the graph, counting from the graph and writing a table, and then inputting the table to the calculator.

Issue 3: separating data by a response

The group who was doing the AP/Honors and work in Issue 2 had another problem. They asked for GPA and the number of hours you worked. But they needed the mean GPA of only those in AP/Honors and those not in AP/Honors, as well as the number of hours worked.

Plot.ly will give us the total 1 variable stats for the column of hours worked, but it will not give it to us in two groups of Y/N based on type of classes taken. It will not do it.

Enter JMP. 6 clicks. Analyze, Distribution, put the variable where you want them, OK.

JMP5

That’s it. You get a 1 variable stats for those who are in AP/Honors, and a separate 1 variable stats for those not in AP/Honors. Doing a two sample t-test is simple and easy once this information is obtained. This is not information Plot.ly can give us.

Issue 4: Linear Regression t-test

Last issue, and then I will stop. I have several learners doing quantitative projects that lend themselves to linear regressions and linear regression t-tests.

Plot.ly makes beautiful scatterplots. You can adjust the axis, overlay the regression line, insert the equation into the graph, etc. They are pretty.

But, if you want a residual plot. No go. If you want to reinforce the statistics of y=a + bx. No go.

This is what it looks like in Plot.ly.

plotly1 You have y=mx + b from algebra, you cannot do residuals, and you CANNOT do a linreg t-test.

In JMP, it looks like this:

JMP4 5 clicks, Analyze, Fit Y by X, put the variables in the correct spots, and hit OK. Notice this is the exact same dialogue box you use for categorical data. JMP uses the same path for different types of data, but tells you in the bottom left corner HOW it will act on your data.

You get output that looks like this:

JMP3 If you want the residual plot, hit the red triangle next to “Linear Fit” and show residual plot. That easy.

Bottom line

Although I fully understand that every single complaint I have had with Plot.ly can be solved by learning the programming language and learning to program the software, I don’t think I can ask high school learners, in the last 4 weeks of class, to learn it so they can do a project on statistics. Honestly, I don’t want to take the time to learn the programming language of Plot.ly so that I can do it for them, either.

Plot.ly makes BEAUTIFUL graphs. It is a powerful platform to show connections between quantitative data sets. But, it does a so-so to bad job on statistics.

JMP makes graphs that may not be beautiful, but the statistics is primary to the operation of the program and makes doing the statistics easy. I think without some major changes to Plot.ly to work towards the statistics side instead of the data representation side I will go back to using JMP next year.

It was just too difficult to teach the way Plot.ly handles or mishandles the stats.

 

Jun 052015
 

Capture

I pushed my AP Stats learners to use Plot.ly this year for their projects instead of JMP as I have in previous years. I am not sure if I like it better or worse, but I definitely have some frustrations.

Let’s go through the good points first.

1. After the learners had their data in Excel, it was very easy to import the .xlsx file into plot.ly. The learners had to make some changes to the first row, but that is to be expected.

2. As long as the learners hit “save” then they did not have to worry about losing their project. I have had previous years where learners lost flash drives or computer files the week before the project is due and had to start from scratch with their hard copy. I appreciate the fact that plot.ly saves the data IF the learners hit save.

3. Once the plots are present, downloading or screen capturing the plots are easy and quick. My learners liked the ability to  quickly make many different plots and then examine them and decide what they plots were really meaning. Changing colors, counts to percents, and other elements of the graphs was easy, fast and very user friendly.

All in all, not too many downsides from the learner’s perspective.

Here are my frustrations with the program as we have been using Plot.ly.

1. Many of my learners did surveys that had categorical Yes, No or Freshmen, Sophomore, Junior Senior responses. After compiling their survey responses, their data looked similar to this:

data

What kind of graph would you make with this type of data? You are correct a bar chart. Bar charts are for categorical data, histograms are for quantitative. So, I do that.

badgraph Not it.  I struggle with this for three days, tweet them for help, more than 4 times, and nada. Zilch. Don’t hear anything back, and am ready to give up on Plot.ly. However, I notice they have a “contact us” in the lower right of the screen. I email them, and a very nice person responds the next day and with instructions on how to make a Histogram.

What. The. Hell. A histogram? I follow her instructions.

data2 (you get the “choose as G” by the “Group by” button) and get this:

goodgraph The y axis is in percent (which takes an extra step to get), clearly what I wanted, but it is not a histogram. I do have a problem with a “Statistics” program that calls a bar graph a histogram. The instructions to make it a stacked bar chart are easy to follow and find, I chose not to do it for this comparison.

2. Ordering the x-axis is a pain. Many of the questions my learners had dealt with the difference between freshmen, sophomores, juniors and seniors. Plot.ly ordered the x-axis based on the order of the data in the spreadsheet. Which means to reorder the x-axis we had to sort the data in excel, (but we don’t want them in alphabetical order?) and reupload.

Really Plot.ly? You don’t have a way to specify the order of the axis? I searched. Trust me I searched long and hard. I ended up just telling my learners to not worry about it.

As a comparison, this is what it looks like in JMP (version 8 is what I have).

jmpdata graphing a “fit y by x”

jmpgraph After hitting “OK”, look at all the stats automatically generated! Also, in the contingency plot (made by default btw) the width is proportional to how many in that column, so the widths AND heights are informative unlike Plot.ly. JMP also automatically generates axis by percent, not counts.

jmpsort Ordering the data is as simple as clicking on Value Ordering under column properties.

I guess what I am saying is that clearly Plot.ly is not meant to be used as I am using it in class. There are easier, faster, and more statistically correct software to use. I will have to figure out what to use for next year because I am not completely sold on Plot.ly, but JMP has to be installed on computers. There are always gives and takes to every decision.

edit:

And right after I posted this, one of my learners walks in tearing her hair out. She has a mixture of categorical and quantitative data, and Plot.ly will not graph the categorical data at all for her. The menu options work completely different for her than for everyone else. She is installing JMP and getting it done that way. Sigh.

May 292015
 

Wow, it has been a while since I posted anything, and I need to share a ton of things I have done. I predict that I will post a lot in the next several weeks. The school year is winding down, but my learners are ramping up. Grad school is down for the summer (with the exception of an independent study on activity theory) so I have much more time to write.

My learners are working on their final exam / projects, and they are hating me right now. They realize that the stats has a purpose, and that it is far harder than they thought. The handout for my assignment is here if you want to use it, or see what I required.

The only reason I veto projects are because it is too easy, too hard (and it is my opinion for that, although we discuss the reason why so they have an opportunity to revise and make it appropriate) or if the subject matter is just too sensitive / personal and it is in the realm of professionals, not high school learners.

Below is the list of surveys / observational studies / experiments that my learners have decided to undertake this year, broken up by period. It is a rather impressive list!

———Period 2———–

  • Social media use / grades
  • How do adults / teenagers differ in choosing restaurants
  • Does quizlet or flashcards help more in learning vocab (using ancient Sumerian words?!)
  • Does education really affect income (using census data from several zipcodes in the city)
  • Is there an association between a school’s weightlifting records and win/loss at sports?
  • Is sex ed successful?
  • Does involvement in club cheer affect grades (4 different age groups)
  • Do taller people run faster, looking at high school, college and Olympic atheletes?
  • Does appearance have an impact on grades?
  • General questions about tobacco use and quitting
  • Which costs more, male or female beauty products?
  • Quality of life of the parents / learners in school
  • Which area of the city has more trash on the sides of the roads?
  • Does music affect memory (experiment)?
  • How do you use social media?
  • What is your perception of LBGT issues?

———Period 3———–

  • How does sports affect grades?
  • Are oreos really double stuffed? (I never showed my class the story on this, this team came up with it on their own! Love it)
  • Is bullying an issue, how large?
  • Are drivers more likely to stop at a stop sign when they are being watched?
  • An experiment on what type of information changes learners opinions on drinking age.
  • Does work hours affect GPA?
  • Does being exempt from an enrichment class at school affect GPA?
  • Are cheetos packaging regarding number of pieces correct?
  • Does social media use hurt GPA?
  • Is the dress code at school appropriate?

———Period 5———–

  • Does the sugar content of cereals affect the placement of the cereals in the grocery store?
  • Does music affect memory?
  • An experiment on whether or not gender effects whether or not people help with dropped books in the hallways.
  • How does our school compare to other schools in the community service of the learners?
  • Does sexism exist in the high school population?
  • Does the perception of animal rights change from learners to adults in the building?
  • What kinds of social media is most prevalent & how should the school use social media?
  • Who is bullied most over social media, males or females?
  • How does M-M vs. F-F & hair length affect the attitudes towards GLBT youth in stores (a very daring observational study)
  • What drugs are prevalently used in the high school per grade level?
  • Is marijuana use a problem in the high school?

As you can see, there is a huge variety (and some major overlap) between the different classes and projects. Each group is working their way to answering their questions, with the final exam being a presentation of their results.

Always exciting.

Feb 092015
 

Besides the usual quote on the board today, I also have this math pickup line: How can I know hundreds of digits of pi and not know your phone number?  I am featuring a new math love / pickup line each day this week (some days will have more than one). If you want the list, Math & Multimedia is the source.

But anyway, I hate to even call this a #180 blog posting, because I gave up on that at the semester. I just was not focused enough to maintain. I don’t know how people do it. But I do want to share some of the Central Limit Theorem Love I just did.

The exercise is not my own. I stole it from Josh Tabor and I credit him fully with the idea. What you need for this exercise are pennies, chart paper, and some fun dots. That’s it. You need a lot of pennies though. By a lot I would estimate I have approximately 2500 pennies in a bucket. I don’t know exactly how many, but it is a huge number. I emailed the staff at the school and asked for pennies and they delivered. Each year I ask for more, and they deliver more. It is terrific.

Okay, on to the set up. When the learners walked in the room, they saw this:

2015-02-06 10.00.15

The instructions, the left chart paper for x’s, the middle for xbar’s and the right for p-hats. Yes, the scale is completely wrong on the p-hat chart. It should be from zero to 1. I fixed that.

Then, the learners pulled their coins, found the means, the proportion greater than 1985, and we graphed using stickers for the x’s, writing xbar and phat for the other two. At this point, we ended up with some good looking graphs. We discussed if we could tell the mean of the dates from the x graph, we decided we could not, so we OBVIOUSLY needed more data.

Do it again.

After two rounds, we ended up with these graphs:

2015-02-09 12.23.42 2015-02-09 12.23.54 2015-02-09 12.24.02

 

I did change the 1985 to 1995 by the time I took these pictures from my 3rd period of Stats. The newer pennies the staff gave me pulled the mean up.

I actually tore the “Actual Values” graph down and threw it on the ground because it was so useless. That was the point of that graph. I loved how the other two graphs were so clearly unimodal and symmetric. They fit the idea of the CLT perfectly. The fact they matched was just icing on the cake!

–http://onlinestatbook.com/stat_sim/sampling_dist/ Using this simulation for the CLT, we then looked at what happens when sample sizes are changed, whether the shape of the population matters, etc. It was very eye-opening.

Then we discussed the reason why, how, and what conditions must occur for one sample to then represent the population. The notes I used are here in pdf format. I am trying something for the end of the year where I post the notes before hand and they are required to read them as homework. I HATE going over the notes in class. So far it is a good experiment.

Next up are some in class problems.

This is the third time I have done this exercise, but only the second time I have used xbars and phats. It is very useful to have those there so the formulas make more sense.

The fact that the formula reads “the population mean is identical to the calculated mean of the sample” is very useful when the learners keep the population mean and the sample mean separate.

Oct 212014
 

My last post was in September and was entitled “I am tired so tired.” That ended up prophetic because with the fall break I ended up not posting for three weeks.  Whew. I needed that break to get back on track and then caught up. I am glad I have my head on right now and am refocused.

So, on to new posts.

Today, Eli Luberof posts on Twitter:

 

Yay! This was amazeballs! You should try it. If you don’t want to try it, I took a screencap of what Stats looks like in Desmos. Desmos 2     

 

This just made my day. Now I can do data entry, just make sure to use the subscripts on the data points and the variables. Notice that you can do different forms of the equations! You can do yhat = a + bx or you can do yhat = mx + b. Either format gives you the r value and the residuals.

Go residual plots! That is awesome in and of itself. I am in love. Right now, the only thing that kind of saddens me is that I can not use “height” and “time” as variables. Desmos needs the x_1 and y_1 format to work. That is sad, because in stats we try to use words as variables. Oh well. At least this gives me a clean, nice, clear way to teach this topic to all classes.

Eli, two thumbs way up for this addition. [And just as an aside to the rest of the #MTBoS to show how responsive Eli is to us. He did a small focus session at #TMC14 with several stats teachers and asked us how we would want to do this. He told us he had not thought about residuals at that time, so to see residuals so easily pop up here was very exciting. Desmos is truly responsive to teachers needs.]  

Edit: Okay, so I kept playing and tried to build a lesson with it on residuals. Found some interesting things that I like and don’t like. I tried to calculate the predicted values, the yhat. Desmos didn’t like merging the algebraic with  the regression. Not at all. This is what I got when I tried: Desmos 3                          

 

 

 

 

 

 

 

I would like to have the ability to show not just the actual value, but also the predicted value. That way I can show where the residual actually comes from. Beggars can’t be choosers though.                      

Edit again: Desmos comes through like a champ. They tweeted this out to me last night.  

 

Which led me to do this:

desmos4Click on it and look at it large. You can see how I used a function per Desmos’ advice to then calculate the residuals instead of just using what is given. This pretty clearly shows where those points at the bottom come from.

I am teaching residuals right now in AP Stats, and I will use this as a demonstration (if it is up long enough) to show what the calculators are doing. Too often the learners don’t think beyond the buttons and just mechanically find the resid plot without thinking about what is going on.

Sep 302014
 

Today wiped me out. I had all 3 sections of AP Stats today, and I heard the same comment from all 3 classes. It went something like this, “I never understood the z score when we did it in Alg 2. My teacher just said, memorize the formula and get find the number.”

Sigh.

That kind of statement just grates on me. We are required to teach it, but some teachers don’t take the time to teach it well, and some just give it a cursory glance and turn learners off.

I am starting from zero with the idea, and building slowly and carefully. It is exhausting though. I never asked who their teachers were (although 3 minutes with the computer will tell me) and I won’t ask. I respect my colleagues too much to think less of them for the destruction of the stats unit.

At least I have learners from my Alg 2 class last year who cheered when I said the phrase “z score”. That made me happy.

Okay, repeat after me: The z score is the number of standard deviations from the mean.

Why over complicate such a simple idea?

Okay, back to grading hell.

Sep 292014
 

I tortured my learners with a game, a game that was awesome and they all agreed was worth while. We played a Stats Pictionary!

I used this document.  Ch 5 – various distributions- Pictionary   I created these distributions using the Illuminations Applet called plopit.   http://www.shodor.org/interactivate/activities/PlopIt/

Here are my rules:

1. Each pair gets one distribution.

2. You have to write your SOCS (Shape, Outlier, Center and Spread) so clearly, using values and descriptive words so that the other learner can duplicate the distribution without asking any questions.

3. Once the SOCS are written, trade papers, and then try to re-create the distributions from the descriptions only. DO NOT SHOW the original.

4. Once the distributions have been done, show the distributions and compare.

5. Repeat.

 

That’s it. Very simple. I did model one for one class. They were struggling with the idea. Once I modeled one, they were fine.

Big takeaways: They realized their SOCS sucked. The figured out what they needed to do to make them not suck, however. Also, the first round went poorly, but they quickly modified their SOCS statements to be clearer.  Finally, Spread was the one thing they still struggle with. They are getting better, but trying to estimate from a graph is hard.

We ended up doing around 4 to 5 graphs in the 35 minutes I allowed for it. It was a great experience I think.

 

I was asked to show my notes. This is the ppt I am using for all of 1 variable quantitative stats. I don’t think it is anything special, but I AM trying to be more creative and thoughtful with it.

I can’t get away from all the notes. I don’t know if it is me, or the material. I do know this is about 14 days worth of notes. I have not done a whole day. A few slides. Stop. Do activities. More notes tomorrow. More activities.  Check out slide 64. 🙂

Categorical & 1 variable Quantitative

 

——————-

Sorry to be silent last week. It was crazy and I was in a spiral of grading hell. I am not out of the grading hell, but I am out of the depression that results from the spiral. Now I am focused and getting caught up.

Sep 232014
 

gottoogreedy

That’s right, they got greedy, and lost. Well, everyone gained, knowledge and skills that is.  Today (and tomorrow in one period) in AP Stats we are playing The game of Greed. This is a great game, that challenges the learners in the end to make box plots and comparison statements about the created data.

You end up with some great data to use in class.

2014-09-23 10.46.52     2014-09-23 14.10.14

 

What is especially great is the right picture, period 5. Notice the big, fat zero? Yes, a female in the class purposefully took zero points. This was a VERY high scoring game as well, the die was very generous to them, and that zero affected everything. I just laughed when she said she was going to purposefully take a zero. It is well within the rules.

This achieved one goal of getting learners talking about the math, at least. 1 thing accomplished today for sure. They also learned more about comparing distributions and using boxplots. 2 and more things accomplished.

 

Algebra 2

This class was awesome today. I gave them a quiz. They had 1 quadratic function in vertex form, 1 in intercept form, and 1 in standard form. They had to turn the one they chose into the other two forms, and then answer all the questions about the function.

Oh, did I mention that if you choose the vertex form, the max points you can earn is 80% of the points? Intercept was worth 90% and standard form worth 100% of the points. They could choose 2 to do, but I would only grade the ONE they told me to.

As I walked around, I saw lots and lots of little mistakes. Silly mistakes. They would be losing, as a class, a ton of points because of not checking signs, and other silly things. I didn’t want that to happen, they knew better, but they were being inattentive to details. So, with 15 minutes of class I told them they could ask anyone in the room any question they wanted to, but they could not ask me.

They figured out pretty quickly they were being silly. Tomorrow’s quiz for real will go differently. Same set-up. Different equations.

Sep 222014
 

Today was a mixed bag of, well, weirdness and frustration with some awesomeness.

I will start with the awesomeness. This morning at 7:15am, a learner from last year walked in and asked for help with his college math class. Loved it. I worked with him for about an hour (into the first class of the day) and he left feeling much better about his class and caught up. I felt really good about being able to continue to help my learners even after they have graduated and moved on.

The frustration was that classes can be so very very different. My one period is chatty. And by chatty I mean so talkative they actually miss out on some of the lesson because they just won’t learn to listen. They are great learners, but the social aspect is killing them. Meanwhile my other two classes have exactly the opposite problem. They are so un-chatty that they sit there in silence waiting for someone to speak up.

The classes were so polar opposite today, and I was completely flummoxed by it. I need to get the one class to talk about the math, and the other classes I need to get to talk about the math! Well, at least it is a common problem.

 

Finally, the weirdness. I gave my AP Stats class this lesson. Ch 4 – Tomato plant experiment But today we were learning how to calculate the fences for outliers and we applied the calculation to data set E.

The NSpire says the data point 20.2 is an outlier, as does the TI-84. But using the 5 number summary and doing 1.5(IQR) + Q3 and Q1-1.5(IQR) we get a fence of 19.95.

The value o 20.2 is not an outlier, but the graphing calculators call it an outlier. That is weird.  I used JMP hoping it would give me different values for the 5 number summary. Nope. Same as the graphing calculators.

This is some weirdness I can’t easily explain, but it did hammer home the idea we should not trust the calculator.