Understanding these basic scientific terms is important so you can interpret data and draw your own conclusions.

When developing an experiment, certain aspects are typically held constant while other aspects are changed.  It is important not to change too many aspects of an experiment at once or the data may not be conclusive, or clear.

• The control is the portion of the experiment that does not vary. For instance, if you want to determine how quickly fabric will fade in the sun, it would be necessary to keep a sample of the fabric away from sunlight so the original color can be compared to the other samples that were exposed to the sunlight.
• The independent variable is the portion of the experiment that is changed. This causes what will happen in the experiment.  If you placed three pieces of the fabric in the sun for a different amount of time, the amount of fading that occurs would vary between the pieces of fabric.  In this instance, the independent variable would be the amount of time each piece of fabric was left in the sun.
• The dependent variable is the outcome, or results, of the experiment. It is dependent on the independent variable.  The dependent variable in our fabric experiment would be how much the fabric color faded.  In this class, you must determine each experiment’s dependent and independent variables.  You must identify these variables in formal lab reports, laboratory assignments, and exams.
• There are also controlled variables. These variables are kept exactly the same for all of the tested items.  Examples of controlled variables in our fabric experiment would include using the same color fabric for each test and cutting all the fabric samples to the same size.

To report on the experimental findings, students will need to collect good data.  Students will be collecting two general types of data in this class: qualitative data and quantitative data.

• Qualitative data is comprised of general observations about the experiment being conducted. This includes shape, color, relative size (large, medium, small), etc.
• Quantitative data is comprised of specific measurements involving numbers that have been collected during the experiment. Examples of quantitative data include volume, density, blood pressure, and temperature.  Including units with quantitative data is important so others who read the data will know how it was measured.

Both of these types of data help to develop a picture of what is occurring and why it is happening when a phenomenon is observed.  Always be sure to write down all of your observations and the data you collect when conducting an experiment.  Do not rely on your memory to recall any information when collecting data because memories are not always reliable or accurate.

During this week’s activity, your instructor will lead you through a scientific study where you will develop a hypothesis, determine possible next steps for research, and draw conclusions based on the information presented.  As this activity is conducted, remember there is no right or wrong hypothesis or incorrect direction of study.  If the data don’t support a hypothesis, it is simply revised or recreated.  The important thing is that the conclusions drawn are supported by the data that has been collected.