Категория: - Bobcat Laboratories
 
 
In today's society of fast-paced crime series on television and high-tech action-filled mystery movies, people are exposed to a broad range of media where the words data and evidence are used interchangeably.  It is, therefore, not surprising to say that this could be confusing due to the misconception that data automatically tells us something important about an investigation. Today we spent our time learning the difference between data and evidence.

To sum up, all data is information. However, evidence is data that can support a claim made by a scientist. Put in another way, all evidence is data but not all data is evidence.

To facilitate this concept, we all participated in an activity called Murder Mystery (created by James Rudd - a former chemical education graduate student from Iowa State University.  I provided a scenario to the students entitled, Who Killed Mr. Xavier, and they were then to develop a solution to the crime. The scenario purposefully does not provide enough data for students to be able to support any claims that they make with evidence. However, the superb imagination and strong opinions of 5th graders did not let such a detail stop them from making claims.  Instead of using scientific data and reasoning, the students used their own imaginations to "create" evidence - which, as any good judge woudl tell you, really is not evidence.

We all had a good time listening to the creative explanations of what had happened to Mr. Xavier. However, due to the lack of information, we will never really know what happened. We can only speculate.
 
Today was an interesting day in class.  We discussed our ideas of what the terms hypothesis, theory, and law mean in regards to how they are used in science.  We started with the word "theory." In everyday usage, it tends to mean an untested idea or opinion.  However, this can be very confusing in science because the word means exactly the opposite.  In science, a theory (e.g., Theory of Plate Tectonics, Atomic Theory, the General Theory of Relativity, or Heliocentrism) refers to a concept that is well supported through extensive and repeated study and testing.  Needless to say, we spent a great deal of our time discussing different scientific theories and how they have been supported by enough evidence to actually be categorized as a scientific theory.

There is a term for an untested idea or opinion, as well, that we spent a large portion of time learning.  That term is "hypothesis." A hypothesis needs has four important parts:
  1. A declarative statement must be made. (i.e., I think it will rain tomorrow...)
  2. Supporting evidence or prior knowledge/understanding. (i.e., ...because it rained today and yesterday.)
  3. Number 1 and Number 2 need to relate to one another. (e.g., it would sound ridiculous to say "I think it will rain tomorrow because I just clipped my dogs's toenails.)
  4. The hypothesis must be a statement with supporting evidence that can be tested through experimentation.


If a hypothesis is not false after being tested over and over and over again, then we as scientists come to accept it as being factual...it can become a "theory."

Finally, we spent a brief amount of time on Scientific Laws.  A scientific law is an attempt to describe the basic nature of the Universe. Some examples include Newton's Laws of Motion, Kepler's Laws of Planetary Motion, and the Laws of Thermodynamics. Although a hypothesis can become a theory, theories do not become laws. 

I realize that this may seem like some really heavy stuff for our 5th grade scientists.  However, they were all evry interested and following the concepts quite well.

A homework assignment was given for the weekend. It can be found here.