Thinking Like a Scientist: Engaged Learning with Students Who Are Blind or Visually Impaired

"This is really interesting!" exclaimed one of my students as she finished processing her data with a volunteer.  She had, in fact, not been looking forward to the number crunching, but found it less unpleasant than expected when she had her results to compare with her hypothesis.  This student was testing the effect of different smells (both pleasant an unpleasant) on stress levels as measured by heartrate.  As a teacher, I love those days when my students are truly engaged and interested in the learning process.  This student found her results "interesting" because she had chosen, designed, and executed the experiment herself.  As my students have discovered, utilizing the scientific method in an actual experiment is often "messy" and always brings the unexpected and ALWAYS includes experimental error.   The scientific method is best taught in the context of completion of a scientific experiment.  We all remember best what we have in fact participated in and not only passively been exposed to.

The Value of Scientific Learning

As teachers we may wonder what value this type of learning brings.  Is it worth using this method, which is more difficult to provide, than typical instruction centered around specific science content?  This type of active learning is, according to much educational research, both more enjoyable for most students and better retained in memory. For example:  When one of my students changed her hypothesis because she realized that a hypothesis was to be based on research and not just a hunch, she both gained a clear understanding of what a hypothesis is and gained valuable experience in how to research. 
The latin word "scientia" on which the word "science"  is based means "knowledge".  The goal of instruction in science should ultimately be to encourage our students' sense of awe in "knowing" new things and not only to "fill" their minds with terminology.
This year half of my students chose to complete science experiments which required testing other people.  This proved to be interesting and engaging for the students and the guinea pigs, though somewhat time-consuming.  As much as possible, I try not to limit my students in their choice of science experiments.  I will use examples from the students' projects to describe the learning process and how completion of the experiment was valuable to their understanding of the scientific method.
The following were topics chosen by my students for study:
  • Which plane will fly the farthest given various wing spans?
  • Who will be able to memorize the most nonconsecutive digits - print or braille users?
  • What effect will pleasant and unpleasant smells have on heartrate?  
  • Who will be more successful in playing audiogames?  the totally blind or those with functional vision?
  • Which pepper will make the spiciest chili?  serrano or jalepeno?
  • Which type of vinegar will cause the greatest reaction with baking soda?
  • Which chocolate will melt fastest?  cookies and cream, milk, or dark?
  • Which material will affect the strength of a magnet most?  aluminum, nickel, leather, or paper?
  • What effect will various music have on stress as measured by heartrate?
  • Which type of soda will cause the greatest explosion with Mentos?
  • Which pattern of fingerprint will be most common?


Learning about Experimental Design

Students gained a better understanding of what constitutes valid data, experimental error,  and the necessity to change methodology as complications arise in experimental design.  They learn that in science questions beget other questions.  They also honed their skills of observation and became better self-advocates. 
Examples of each of these valuable lessons include:

What constitutes "good" data?

During numerous trials experimental error occured that caused students to consider whether to include the trial or not. For instance, when testing one subject who was completing a task requiring concentration, the students were interrupted.  This trial was not used in the data. 

Experimental error

It can be said that experimental error is the rule rather than the exception in scientific experimentation.  The students learned that experimental error can result due to human error, or inadequacies in the equipment used, etc.  In several experiments which required a measurement of heartrate, the data was suspect because the students ran their experiments without an accurate instrument to take heartrate.  Each of my students became aware of the experimental error in his/her own experiment. This translated into the realization that it is a concern in all experiments.  For those students who utilized human subjects, it was clear that it is difficult to control all variables besides the independent variable.  All of these cases of experimental error allowed for a discussion of the importance of minimizing error in an experiment yet understanding that it will be present.

Complications in experimental research design

Technical complications were common in my students' experiments this year.  One example was the difficulty we had in finding the correct type of splitter to use for the audiogame to allow the experimenter to listen at the same time as the subject.   Students learned that methods for scientific research are always evolving to reflect not only best practices, but also the necessary corrections, based on lessons learned in early trials. 
As an added benefit of completing a science experiment, students gain skills in the expanded core curriculum, such as self-advocacy.  For example, often students need to contact someone in connection with their project.  This is most often a store which may sell an item needed for the project.  This comes very naturally for some, but is a real struggle for others.  When I sense that a student is uncomfortable, I have him practice what he is going to say before making the call.  One student this year both advocated to install necessary software on the computer for his project and advocated for a piece of equipment that he needed. 

Terms related to the scientific method:

  • hypothesis - a statement or prediction that can be tested
  • independent variable - the variable that is changed in an experiment
  • dependent variable - the factor that is measured in an experiment
  • constant - variables that are not changed, but stay the same
  • control - sample treated like other experimental groups without the independent variable applied to it. 
  • experimental research design - testing a hypothesis through the use of a series of carefully controlled steps
  • descriptive research - answering scientific questions through observation
  • experimental error - errors that may occur in the execution of a science experiment

Take- Aways

  • Encourage students to think about their results. 
  • What does this data mean? 
  • What could have caused experimental error? 
  • How would he/she change the method used to test the hypothesis on a future trial based on experimental error or complications which arose? 
  • What other questions might be asked related to this content? 
  • Should all of the test subjects utilized be included in the results? 
  • Was there significant enough experimental error in any case to eliminate that subject from the data pool?
In conclusion, I have observed that many of my students at TSBVI had never completed a science project prior to arriving at TSBVI.  I am not sure why this is the case, but can only assume that possibly some students with visual impairment are exempted from this valuable assignment.  As there are clear benefits to students in utilizing the scientific method as outlined in this blog, I would recommend that itinerant TVIs suggest to the science teacher that this requirement is appropriate for the student with a visual impairment and that it not be waived. 
Please also see the excellent blog post by Kate Fraser for an outline of the scientific method and more information on encouraging students with visual impairment to participate in a science fair. 


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