Monday, April 1, 2013

Box and Whiskers Plot

So, today I had the opportunity to do something different. I got to work with 8th grade students on Box and Whiskers Plot. Now, I know I am not an expert and I know I missed identifying an outlier, but our goal for this tutorial session was to teach a basic understanding of Box and Whiskers Plot. Their teacher liked my lesson and the kids loved it, so I thought I would share.

My principal asked me if i knew much about Box and Whiskers Plots? I said that I knew a little bit and I have an idea to make it slightly more hands on.

I pulled some data from a textbook and put it on individual pieces of paper creating eight sets.

Here's what I did...

Each table received a sheet of poster paper and a stack of cards with numbers written on them.

My example was taped to a write board with the cards taped in a scattered unorganized manner. I worked through the first data set with them.

Teacher: "What do you call a set of values randomly given?"

I was looking for the word "data". After I guided them there...

Teacher: "What should be the first thing we do with data?"

Students: "Put the data in order from least to greatest."

Teacher: "What are the four measures of central tendency or variability?"

Students: "Mean, Median, Mode, and Range."

I then proceeded to ask the students to define and explain the process used to determine each.

Teacher: "Median is the essential tool in creating a Box and Whiskers Plot."

I then had them find the median of the data.

Teacher: "What is the minimum and maximum value of the data?"

Student: "28 and 67."

Teacher: "Understanding the information in a Box and Whisker Plot is determined by a number line placed below indicating the values used. What would be an appropriate range and scaling for a number line here? ... Another words, what would be a pretty minimum and maximum value that we could use?"

Students: "From 20 to 70 and go by fives."

Each table constructed a number line with the appropriate values and scaling.

Teacher: "Now, let's go back to our data. We need to determine the lower and upper quartile."

I explained the process (similar to median) and why it's called upper, lower, and quartile.

Teacher: "How many significant values have we identified?"

Students: "Five."

Teacher: "Using a short vertical line, let's identify the location of each value along our number line. You then connect the lower quartile to the upper quartile using two parallel lines. What did this create?"

Students: "Two boxes."

Teacher: "Then you connect the minimum to the lower quartile and the upper quartile to the maximum using a single horizontal line. What do you think we call these?"

Students: "Whiskers!"

Teacher: "What do you think is the significance of this type of graph?"

We spent several minutes discussing this before I gave them a new set cards.

I wanted to share this because it was well received. I don't know if it was because I'm not their usual teacher or they were really into it, but this lesson was refreshingly engaging and fun. It was one of those lessons that just worked, flowed, and the kids really connected. If you're a teacher, I'm sure you know what I mean.

Thank you.