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.

A cause and effect relationship is when one event or characteristic results in another.  Scientists attempt to understand and explain cause and effect relationships so that they can help prepare the world for future events and conditions, while searching for immediate solutions to prevent/reduce/address current problems and conditions.

Scientists often use the transitional "signal" words and phrases to indicate cause and effect relationships. You can explain a cause and effect relationship using these words and phrases, and/or identify cause and effect relationships written by other scientists upon spotting these words and phrases in published scientific studies.

As scientists, we make observations, and then allow those observations to inspire scientific questions. Consequently, these fascinating questions drive us to investigate for answers.  One observation scientists have noted worldwide is the dramatic increase in carbon dioxide, methane, and nitrous oxide in the Earth's atmosphere over the past 50 years.  What is the cause of this change?  What is the effect of this change?  You might ask?

Well, lets first take it back to the basic composition and function of the Earth's atmosphere.  The Earth's atmosphere is made up of a mixture of gases-- mostly Nitrogen, Oxygen, water vapor (the gas state of water)-- which is held in place by Earth's gravity.  The atmosphere acts like a blanket for the Earth, keeping it nice and warm, while protecting it from the Sun's harmful ultraviolet rays.  

The recent increase in carbon dioxide, methane, and nitrous oxide (also known as "greenhouse gases") in the Earth's atmosphere has a similar effect of adding more mass to a blanket: more heat gets trapped underneath, and the temperature rises. This phenomena of rising temperatures in the Earth's atmosphere due to the increase in greenhouse gases is called global warming.  But what is the cause of the increase in these greenhouse gases?  Here is what the students of MS 88 concluded upon examining a series of images and captions from an article published by NASA:

• “People want corn and corn products faster and cheaper.  As a result, more chemical fertilizers are used, which give off nitrous oxide.  Therefore, there is an increase in nitrous oxide in the Earth’s atmosphere.”
• “People around the world love McDonalds.  Consequently, the amount of livestock increases, which produce more methane gas.  As a result, there is an increase in methane gas in the Earth’s atmosphere.”
• "People buy more and waste more.  Therefore, landfills are packed, giving off a ton of methane gas.  This leads to an increase in methane gas in the Earth’s atmosphere.”
• “People love to drive big, fancy cars.  That is why more gasoline is burned, putting more carbon dioxide in the atmosphere.  Therefore, there is an increase in carbon dioxide in the Earth’s atmosphere.”
• “People use and waste a lot of paper products.  Therefore, more forests, which usually absorb carbon dioxide from the atmosphere, are cut down.  As a result, there is an increase in carbon dioxide lingering in the Earth’s atmosphere.”
• “People love their electronic gadgets.  Consequently, more fossil fuels are burned to provide electricity.  Therefore, there is an increase in carbon dioxide in the Earth’s atmosphere.”

To learn more about what other scientists are observing and predicting to be the effects of global warming, check out the following websites:

• http://environment.nationalgeographic.com/environment/global-warming/gw-effects/
  
• http://planetsave.com/2009/06/07/global-warming-effects-and-causes-a-top-10-list/
  
• http://www.climatehotmap.org/global-warming-effects/
• http://timeforchange.org/cause-and-effect-for-global-warming

Homework: Read at least two of the articles above.  Then write 3 different effects of the increase in carbon dioxide, methane, and nitrous oxide in the Earth's atmosphere.  Make sure to use the transitional cause and effect "signal" words (above), and write in complete sentences.  Use the example sentences to help get you started.  Remember, we are discussing EFFECTS this time, not causes.

• "The result of the increase in carbon dioxide, methane, and nitrous oxide in the Earth's atmosphere is ________________."
• As a result of the increase in carbon dioxide, methane, and nitrous oxide in the Earth's atmosphere, __________________."
• "The effect of the increase in carbon dioxide, methane, and nitrous oxide in the Earth's atmosphere is. _______________."
• "One effect of global warming due to the increase in greenhouse gases is ____________."