Scientists change and shape our world by developing explanations and making sense of the things we do not know or do not understand in our world (and outside of our world).  For example, Louis Pasteur's controlled experiment that investigated the question, "Can microorganisms (germs) generate spontaneously?" has completely changed modern medicine.  Pasteur proved that microorganisms do not grow randomly, and that microorganisms must travel through the air or through direct physical contact in order to grow.  

As result of Pasteur's experiment, billions and billions of lives have been saved.  For hundreds of years now, doctors around the world make sure to wash their hands and sanitize facilities to keep disease-causing germs from spreading.  In our school, we know always to wash our hands before and after experimenting, and to cover our mouths when sneezing.  We have Louis Pasteur to thank!

In-Class Assignment
Answer the questions below in your science notebook.  Write the question and answer in COMPLETE sentences.

1.  How did Louis Pasteur's experiment change/shape our world?

2.  Pick the testable question (among those you have written) that means the most to you.  What is the purpose of this testable question?  

3.  WHO could benefit from the information you gather through your scientific investigation? 

4.  HOW might those individuals benefit from the information you gather through your scientific investigation?

5.  What materials will you need to conduct the experiment (include people, place, and things)?

6.  Identify the variables in your experiment:
     IV: __________________________________________________________
     DV: _________________________________________________________
     C: __________________________________________________________
     CG: _________________________________________________________

7.  What materials will you need to measure your dependent variable?

8.  What might be difficult about conducting your experiment/collecting data?

Scientific Method = Gathering Evidence

Last week, we learned that the Scientific Method is an organized method used by scientists to find and gather evidence (data) to support a claim (argument) about what the scientist observes.  There are many versions of the scientific method, but all versions of the scientific method involve trying to answer a specific question, and experimenting to find the answer.

The version of the scientific method that we will use in my class was given to me by my dear friend, Dr. OPHERC:

• Observation: The observation is simply any information gathered using the senses or an instrument.  A scientific investigation begins with an interesting observation in the world that generates questions that can be tested.

• Problem/Question: The problem/question is the specific question the scientist will attempt to answer through experimentation.

• Hypothesis: The hypothesis is the claim of the scientist, or an educated guess about the answer to the problem/question.  A hypothesis is based on sufficient observations, prior knowledge, and background research.  

• Experiment: The experiment is when the scientist actually tests his/her hypothesis for supporting evidence using detailed procedures, appropriate materials, and scientific measuring tools.  During the experiment, the scientist records all of his/her qualitative and quantitative observations.

• Results: The results are all of evidence (the qualitative and quantitative observations) gathered throughout the experiment.  The results are often displayed in tables, charts, and graphs for further studying. 

• Conclusion: The conclusion is the reasoning of the scientist that explains the meaning or significance of the results.  In the conclusion, the scientist links the evidence from the experiment back to the original claim (hypothesis).     

Scientific Explanation = Goal of a Scientist

During the first week of school, we learned that science is a way to develop explanations for what we observe, using the evidence we gather through our own experiments, and through the experiments of other scientists.  A scientific explanation, so to speak, is the scientific way of explaining what we observe in the world (and outside of the world, too!).  A scientific explanation is essentially a claim (about what a scientist observes/observed phenomena) that is supported with evidence and reasoning.  
The goal of a scientist is to develop scientific explanations to share with the scientific community, and the purpose scientific method is to gather the "evidence" component of the scientific explanation.  

But what is a claim?  What is evidence?  And what is reasoning?!  These components of a scientific explanation (C.E.R.) have been outlined below.

C.E.R. = Parts of a Scientific Explanation

• Claim: a conclusion that attempts to answer/address a testable scientific question. 
• Evidence: appropriate and sufficient data from an experiment, other scientists' experiments, reading material, and/or other observations that support the claim.  
• Reasoning: a justification that links the claim and evidence that incorporates appropriate and sufficient scientific principles; requires background research.  

Connecting the Scientific Method with C.E.R.

Last week, we performed an experiment to gather evidence in order to develop a scientific explanation. The question we addressed was, "What is the most common color in a 2.17 oz Original Fruit bag of Skittles?"

Below is an outline of how we gathered our evidence via the Dr. OPHERC.  We will use class 711's data for our example.

1.  The scientific method began with an observation.

Observation: There are five different colors in a bag of skittles - red, yellow, orange, green, purple.  Every time I eat a bag of skittles, the frequency (how many) of each color seems to be different.  

2.  This observation inspired, or led to, a question for investigation.

Problem/Question: What is the most common color in a 2.17 oz "Original Fruit" bag of Skittles?  

3.  We made a tentative claim (hypothesis) to test, based on our observations, background research, and prior knowledge.

Hypothesis: If purple is the most popular color of Skittles, then it will be the most common color in a 2.17 oz bag because the makers of Skittles will likely accommodate the preference of the consumers.  Furthermore, according to Skittles.com, green should make up 19.7% of a 2.17 oz bag, yellow should make up 19.5% of a 2.17 oz bag, orange should make up 20.2% of a 2.17 oz bag, red should make up 20% of a 2.17 oz bag, and purple should make up 20.6% of a 2.17 oz bag. 

4.  We then tested our hypothesis through an experiment to gather evidence.

Experimental Procedure:
1.  Open the bag of Skittles onto your sheet of paper towel.
2.  Group your Skittles according to color. 
3.  Count how many of each color are present in your group’s bag and record this info in table 1.   
4.  Analyze your data by creating a bar graph on Table 2.
5.  Make sure to label the graph showing colors and numbers of Skittles. 
6.  Form a conclusion.  State whether your hypothesis was correct or incorrect and why. 

5.  Next, we graphed all of our data (evidence).

Results:
Average number of red (class 711): 11.5 pieces
Average number of yellow (class 711): 13.3 pieces
Average number of orange (class 711): 10.2 pieces
Average number of green (class  711): 13.5 pieces
Average number of purple (class 711): 10.2 pieces

6.  We then made a conclusion by determining whether or not the evidence gathered supported our original claim.  The conclusion is essentially our reasoning.  The conclusion addresses our original claim (was it correct?  incorrect?), provides our evidence, and links our evidence back to our original claim.

Conclusion: My hypothesis was not supported through this experiment because I predicted that purple would be the most common color, and my results show that green is the most common color in this experiment.  The average total number of candies in class 711 was 58.6 pieces.  There was an average of 10.2 red candies, 13.3 yellow candies, 10.2 orange candies, 13.5 green candies, and 10.2 purple candies in a 2.17 oz bag.  Class 711's results were different from class 711, 714, 715, and 716. My next step is to average the data from all four classes.  Since every class has a different average frequency of colors, the results do not provide enough evidence to support or oppose my claim that purple is the most common color of skittles in a 2.17 oz bag.  Furthermore, since Skittles.com states that green should make up 19.7% of a 2.17 oz bag, yellow should make up 19.5% of a 2.17 oz bag, orange should make up 20.2% of a 2.17 oz bag, red should make up 20% of a 2.17 oz bag, and purple should make up 20.6% of a 2.17 oz bag, it is important that we increase our sample size in order to have a fair test.

Homework:

Answer the following questions in your science notebook.  Write the questions AND answer in complete sentences.

1.  Why do scientists use the scientific method?
2.  What is a scientific explanation according to this article?  Cite your evidence.
3.  How is the "reasoning" in a scientific explanation related to the claim and evidence?  Explain.
4.  According to this blog post, a claim is a conclusion that attempts to answer/address a testable scientific question.  What is another way to define claim?
5.  According to this blog post, evidence is appropriate and sufficient data from an experiment, other scientists' experiments, reading material, and/or other observations that support the claim.  What is another way to define evidence?
6.  Were we able to gather enough evidence through our Skittles experiment to support a claim that a particular color is the most common in a 2.17 oz bag of "Original Fruit" Skittles? Explain.
7.  Using the scientific method does not always provide the necessary evidence to support the claim (hypothesis) of the scientist.  What do you think a scientist should do in the case that the evidence does not support the claim (hypothesis)?  Explain what you think should be the next steps for the scientist.

Due: Monday, October 21, 2013.

Take a look at the image on the left.  What do you observe?  A pair of eyes?  A nose?  A raccoon?

In reality, the image is a picture of a South African moth using "eye-spot mimicry".  Check out a picture of the moth taken from a different perspective here.  Surprised?

If your instinct was to try to guess what was "in" the image, you are not alone.  It is a very tempting response to the question, "What do you observe?".  However, as scientists, it is important that we understand the difference between what we observe, and what we infer. In this blog post, we will first learn about observations, the types of observations, and the relationship between observations and data.  We will then look into inferences, and how we can use our observations in order to make scientific inferences.

Observations

In reality, an observation is any information you can gather using the five senses and scientific instruments and tools.  In other words, what can we actually see, smell, taste, touch, hear, and measure in the picture?  There are two sets of concentric circles, the colors of burnt red, orange, white, and varying shades of brown, and symmetrical patterns and colors.

All observations are classified into one of two categories: qualitative observations and quantitative observations.  Qualitative observations describe the characteristics or qualities of something with words, such as color, odor, texture, sound, taste, etc.  Quantitative observations describe the measurement or quantity of something with numbers and a unit of measurement, such as "10 feet" or "150 grams".  Keep in mind that the unit is extremely important; it is the only part of the observation that actually tells us the meaning of that number.

When a scientist collects data, he/she is simply gathering and recording qualitative and quantitative observations.  Data describes all of the qualitative and quantitative observations that are collected as part of an experiment.  Some experiments involve making more qualitative observations, while others involve making more quantitative observations.  However, most experimental data is a combination of both qualitative and quantitative observations.  For example, scientists who are studying the effects of global warming refer to both qualitative and quantitative data.

Inferences

On the other hand, an inference is a logical conclusion based on observations and prior knowledge. "Based on my observations of the tomatoes, I can infer that the tomatoes are fresh because they are bright red, round, and shiny, and have a mass of 15.5 grams, which means that the tomatoes have a reasonably high water content."  In this example inference sentence, note how I incorporated both qualitative observations, quantitative observations, and prior knowledge in the "because" portion of the sentence.  Without this important "because", I would not be fully supporting my logical conclusion (inference).

Let's go back to our first picture example.  I can infer that the object in the image is a winged insect using "eyespot mimicry" because of the symmetrical patterns and colors, concentric circles, and soft appearance.  Again, note how the "because" portion of the inference is where I incorporated my observations and prior knowledge.

Below are example sentences to help you write your own scientific inferences:

• “I infer ___________________, because ________________________."
• “Because _________________, I infer __________________________.”
• “Based on my observations, I infer ________, because _____________.”

Check out the video below, created by Mr. Epp's science classroom.  When watching the video, keep in mind that the word "precise" means accurate and exact.

As scientists, it is very important that we understand the relationship between observations and inferences.  In order to make a scientific inference, we must consider all qualitative and quantitative observations before making any conclusions.  As we move into developing our own scientific investigations this school year, keep in mind that we will be collecting data (qualitative and quantitative observations) to develop our own scientific inferences and explanations of the phenomena we observe.