Conclusion - Evaluating the Results

After you have completed your experiment, you need to evaluate the results.    Make a computer graph with your experiment results BEFORE you begin your conclusion section.  Graphs help you to see trends and patterns in the results.

Look at the Tables and Graphs and Evaluate the results of your experiment by asking yourself the following:

1. What happened in my experiment?  Using your results, write down the following information from your Table of Results:
   1. If you measured using metric units (distance, mass, temperature, time), write down the following:
      1. Highest number for each variable tested
      2. Lowest number for each variable tested
      3. The average number (from all the trials) for each variable tested.
   2. If your results were an Observation, write down the following:
      1. What changed (color change, size, density, etc.)
      2. How did it change?

2. Evaluating Experimental Error:

In science we use measurements to help us observe the changes we see when we perform experiments.   A student may ask why the measurements will be different when we are completing the SAME experiment using the SAME equipment.  Whenever we measure using a piece of scientific equipment there will ALWAYS be some errors.   The main idea the scientist should understand is that the most common measurement errors are:

1. The person doing the measuring does not read the equipment correctly.
2. The precision of the equipment being used. (For example, a metric ruler can measure to the nearest millimeter, a metric caliper can measure to the nearest thousandth of a millimeter)
3. Environmental conditions during measurement (Was there a major change in temperature that could affect the measurement results?)

There are several ways that we can CONTROL experimental error when completing a science experiment.  The following errors are associated with experiments:

1.  Measurement Errors -  More precise equipment = less error in results.  Any measuring done in science has SOME ERROR associated with it.   Example: 
   1. Using a metric ruler to measure thickness gives accuracy to the nearest millimeter.
   2. Using a metric caliper to measure thickness gives accuracy to the a micrometer.
2. Interpretation Errors – Did the scientist have an adequate number of trials to be able to make a conclusion based on the testing completed?

           Example:

1. An experiment has 15 trials with distances being measured
2. An experiment has 150 trials with distances being measured

Which experiment will give more accurate information? (150 trials!)