Monthly Archives: March 2014

The pas de deux of questions and answers

Can’t Have One without the Other: Questions and Answers

The first of the science and engineering practices is “asking questions” followed by numbers two through eight focused on how to construct answers. As we progress through school, we are taught the answers (the three causes of the Civil War, the capital of Delaware, and Avagadro’s number) but not necessarily the questions from which they sprang. The following presents an example that shows why it makes sense to keep questions and answers together.

First a little test.

 How many different smells or odors can humans identify?

a) 25.

b)  10,000.

c) 250,000

d) more than 1 trillion.

 

If you look in the textbook called Molecular Cell Biology, by Alberts and others, 4th edition, 2002, where you would have found:

“Humans can distinguish more than 10,000 different smells (odorants), which are detected by specialized olfactory receptor neurons lighting the nose… It is thought that there are hundreds of different olfactory receptors, each encoded by a different gene and each recognizing different odorants.”

 

It looks like the number 10,000 is a good bet to be the correct answer.

However, Avery Gilbert, a sensory psychologist and author of What the Nose Knows, was always suspicious of this “fact.”

Something about it has always bothered me—why such a nice fat round number? Why was there no date of discovery? And, strangest of all, why did nobody take credit for it?

Dr. Gilbert found out the origin for the “answer” of 10,000.

Back in 1927, two American chemists —Ernest C. Crocker and Lloyd F. Henderson —searched for the answer to the question “is it possible to create a numerical coding system in which any smell could be assigned a four-digit identifier?”

In developing their classification system the chemists found out that using their coding system it was mathematically possible to identify 6,561 different smells. The number was later rounded up to 10,000.

The chemists never conducted an actual experiment to test the smell-ability of actual humans. So while 10,000 is indeed an answer, it is most certainly not the answer.

What the original quest? How many odors can a human being detect?

The March 24, 2014, edition of The Washington Post reported the results of an experiment done to answer that question. The research was done at the Rockefeller University in New York.

The experiment’s chief investigator, molecular neurobiologist Leslie Vosshall, developed an experiment modeled on how hearing exams are conducted. In a hearing test listeners must try to distinguish between different tones. In the Rockefeller experiment 26 different noses were put to the test. “Each individual was given three vials, two of them containing the same sand and has to determine which smell was the odd one out.”

As a result of data gathered in the hundreds of repetitions, the researchers assumed that subjects’ performances on the test would be similar if asked to recognize more of the possible smells that could be produced in the lab. From these data it would appear that the average human should be able to distinguish at least 1 trillion different odors. The study was published online in the journal Science. (www.washingtonpost.com, March 21, 2014)

The point is that questions and answers are related in a pas de deux, a dance in which two dance partners follow one another’s steps.

It seems that if you want to understand the answer, you also must  know the question.

 

References

Avery Gilbert’s blog First Nerve http://www.firstnerve.com/2008/09/10000-different-smells-enough-already.html

 

Washington Post, March 20, 2014. http://www.washingtonpost.com/national/health-science/human-nose-can-detect-at-least-1-trillion-odors–far-more-than-thought-says-study-of-smell/2014/03/20/ffb8644a-af95-11e3-95e8-39bef8e9a48b_story.html

Science and Engineering Practices: The Scientific Culture

Science and Engineering Practices: Slow Down Thinking, Improve Learning

We love those questions that are answered quickly. The rapid answer provides closure and keeps you coming back for more. Hence, the enduring popularity of game shows like Jeopardy. 

Today the focus is on how we are able to answer quickly and why that is a mixed blessing.

We have two systems, a fast one and a slow one that help us process our interactions with the world.

In his book Thinking, Fast and Slow, Daniel Kahneman describes the two. System 1 is our automatic system. It works very quickly, often before you are aware that a “question” has been posted. For example, you are driving down a dark road. It is cold and there is some moisture on the road. Before you are aware that the moisture is ice, System 1 is working out the answer to the question: “which way would you turn the steering wheel when the car begins to skid?” and is implementing it almost before you are aware that the car is skidding.  System 1 is also operating when you walk into a room and instantly it lets you know the answer to the question “who are they talking about?” is you! This is the system that evolved to help us respond to danger.

System 2 is the one that we use when our conscious mind is required to answer a question; such as, multiplying 27×18, comprehending a paragraph about reduction-oxidation equations in chemistry, or chairing a committee whose task is to recommend a new math series for the elementary school.

While System 1 is fast and seemingly effortless, it can be fooled quite easily.

What do you see in the box below?

 Image

Your System 1 let you see immediately that one line was longer than the other.

If you invoked System 2  by asking, “maybe it’s a trick. Are the lines really the same length?” You tested what your eyes saw by measuring with a ruler. The lines are the same length.

Kahneman observes that

If asked about their length, you will say what you know. But you will still see the bottom line as longer. You have chosen to believe the measurement, but you cannot prevent System 1 from doing its thing; you cannot decide to see the lines as equal, although you know they are. To resist the illusion, there’s only one thing you can do: you must learn to mistrust your impression of the length of lines when fins are attached to them. To implement that rule, you must be able to recognize the illusory pattern and recall what you know about it. If you can do this, you will never again be fooled by the Müller-Lyer illusion. But you will still see one line as longer than the other.

Unfortunately, classroom culture often discourages the use of System 2, the system of rational thought, by its emphasis on students responding quickly to questions.

The culture of science, in contrast, has developed a culture of deliberation when trying to make sense of what is seen. Asking questions, building models, testing the models, gathering and evaluating the data, contracting explanations, arguing from evidence, and gathering, evaluating, and sharing information in a community of peers all encourage the use of rational thought (System 2) to make sense of the world.

The eight science and engineering practices from the Framework for K-12 Science Education give teachers a powerful way to create a classroom culture that is scientific because it relies on the thoughtful consideration of our observations.

I think that the science and engineering practices are not to be thought of as something that is added on to a lesson (Today, let’s all think of a question.”).  Rather the practices provide a foundation for how a teacher develops the culture his or her classroom almost in the same way that classroom manners are built in to its day to day life.

The mind is powerful but it can be fooled. But if it has developed the habits of thoughtfulness, its owner will be a lifelong learner.

Daniel Kahneman, Thinking, Fast and Slow. Farrar, Straus, and Giroux. New York. 2011. Winner of the National Academy of Science Book of the Year for 2012.

Daniel Willingham, Why Students Don’t Like School: A Cognitive Scientist Answers About How the Mind Works and What It Means for Your Classroom. Jossey-Bass. San Francisco. 2009.

Also check an article in Science Scope, Vol. 37, No. 3, November 2013, “Evaluating Scientific Arguments with Slow Thinking,” by Beth A Covitt, Cornelia B. Harris, and Charles W. Anderson.

Questions?

Questions?

There is an answer to every question. To find the answer, just ask an authority; the host of the quiz show, an encyclopedia, the Internet, a teacher, or anyone who has the answer book!).

Even with questions that do not have simple answers; such as, “What about the Ukraine and Russia?” The experts on Eastern Europe and their  colleagues will pop up several times each hour on your favorite source for news and information. In 90 seconds or fewer the expert will give us the answer. Whatever the question, someone has the answer!

Finding answers to questions is easy; whether the answer is correct is quite another matter.

It is easy to find “answers” both wrong and which caused real problems.

For example,  really important question was what caused “malarial fevers?” The question mattered because during the history of South Carolina from it’s founding through the beginning of the 20th century, lots of people were sickened and often died of malarial fevers. Fevers were specially bad in South Carolina and particularly severe during the long and torrid summers.

But for most of South Carolina’s (and the world’s) history, the question “what causes malarial fevers?” was really not a question because everybody knew the answer.  

The answer had been handed down from father to son and mother to daughter at least since the time of the Romans.

The answer: “Malarial fevers are caused by inhaling “bad” air, or as the Italians called it “mala-aria,” literally bad air.

The answer was so firmly accepted as true, that when the city of Columbia was planned in 1787, it was to be located at the top of a hill and its streets were to be extra wide (150’!) so that even a slight breeze would blow away the bad air.

The odd part of the story is that for over a thousand years, the strategy of fighting malarial fevers with fresh air showed no tangible results. People still caught malaria and died of malaria, even in well-aired and breezy houses sited on high hills.

Once we have an “answer,” we hold on to it even when there is a huge amount of evidence that it is wrong.

Answers can be deadly. Knowing the “answer” may make it less likely that people would ask the questions that might lead to better answers.

Daniel Kahneman has identified a three fallacies that occur when we jump to answers without asking enough questions.

The three fallacies:

1. WYSIATI (What You See Is All There Is); that is, there may be other factors that we have failed to notice like the prevalence of certain types of mosquitoes during the summer time when fevers are rampant. However, we  don’t look because further because we already know the answer.

2. Answering an Easier Question: We substitute an easier question to answer.  Instead of asking further, more difficult questions (like “why is the solution not working?) we pose ourselves easier question: “how do we get rid of the bad odors?”; and finally;

3. Confirmation bias: we become biased towards data that confirms what we already think we know. Since we already know the answer, the fact that the city smells even worse during the heat of the summer and fever rates increase, using carbolic acid on the street seems to be a reasonable solution.

While the textbook version of science is largely the history of the answers like “Pasteur discovered the process of fermentation” or Becquerel discovered X-Rays” a more informative way to look at science is to begin with the questions that Pasteur, Becquerel asked. The history of our understanding natural phenomena is really better told as a chain of questions, with one question leading to yet more questions. Instead, the textbook version of science is largely told as a set of answers.

Richard Feynman asserts that one of the qualities of science is that it teaches “the value of rational thought.” I think that the lesson is that rational thought begins with questions.

 

Daniel Kahnemann, Thinking, Fast and Slow. Farrar, Straus, and Giroux. New York, 2011.

Behind the Classroom Door

Behind the Classroom Door      

For the past century the major project in schools has been and is to improve instruction by implementing research based instructional practices. Findings from the Study of Instructional Improvement (SII) gives even more insight into why the project has been and will continue to be so difficult.

The study was conducted (2004-2009) by the University of Michigan to follow the progress of schools that had adopted one or another of the Comprehensive School Reform (CSR) models promoted by the U.S.Department of Education.[1] The part of the study that gives insight into the difficulty of the improvement project is its look behind the classroom door.

The unit of reform has traditionally been the school. Our accountability system gives report cards to schools and districts. It is assumed that what is said about the school is also true about the class rooms in that school.

To test this assumption, the SII asked the question: what is really happening day by day in individual classrooms of the 112 participating schools?  Each teachers in each of the participating schools was asked to keep a detailed log of what he or she taught each day. A log would record, for example, “today we worked on word analysis,” or “the emphasis today was on reading comprehension.”

Reading the logs from the several hundred teachers was like opening classroom doors.

The most significant finding was that what took place day to day differed considerably class room to class room, even at the same grade level in the same school.           

For example, a fifth grade teacher’s day to day work in reading would be different from his or her next door neighbor’s class room. One teacher would spend 140 out of 180 days working on reading comprehension while his or her neighbor spent 40 days on comprehension and 140 days on word study. Another teacher would teach a highly structured writing process while a neighbor would ask the kids to produce much more writing and comment extensively on each paper. 

The important point is that what a child is likely to learn on a given day is highly variable in both the topic and the cognitive level. One student might experience ELA in terms of a lot of writing, while another student in the same grade at the same school would spend his or her time identifying subjects and verbs on worksheets.   

The study underlines a long understood but seldom discussed fact about schools. The differences from classroom to classroom in any given school are greater than differences between individual schools. (http://hepg.org/hel/article/427#home).

When the school is the unit of measure, the averaging of the data washes out the variations.  In contrast the view from inside the classroom shows a much more complex world in which a teacher interacts with a group of kids by using a set of instructional materials that are enacted based on the individual teacher’s understanding of the task based his or her individual understanding of mandates from the school’s administration.       

Given what we see behind the classroom door, one student’s learning experiences are likely to differ significantly from another and what she does or does not learn will also differ.

The quest to improve learning is more than implementing an “innovation.”  It also means that the teachers who work in a school need to come together as a team who agree on certain basic understandings about how each enacts the school’s instructional program.

 


[1]You can read more about the study at (http://www.sii.soe.umich.edu/about/pubs.html