The Basics of Experimentation: Original Material by T. Brown 2005 An examples of how to set up and conduct a basic experiment. Original Material by T. Brown 2005

Original Material by T. Brown 2005 FERTILIZER GIVEN TO THESE A Basic Experiment Set Up Properly: Experimental Group Control Group Original Material by T. Brown 2005

Original Material by T. Brown 2005 FERTILIZER GIVEN TO THESE A Basic Experiment Set Up Properly: Background: Here a scientist has created a new kind of plant fertilizer (Fertilizer A: purple) that she thinks will increase plant growth better than standard fertilizer (blue). She wished to design and conduct an experiment to support her hypothesis. If Fertilizer A is superior, then plants given Fertilizer A will grow larger than plants given standard fertilizer, because Fertilizer A is more nutritious and better formulated to the growth needs of plants. Original Material by T. Brown 2005

Original Material by T. Brown 2005 FERTILIZER GIVEN TO THESE In this experiment the INDEPENDENT VARIABLE (IV) is the new formula of plant fertilizer (Fertilizer A). The DEPENDENT VARIABLE (DV) is the size of the plants. Original Material by T. Brown 2005

Original Material by T. Brown 2005 FERTILIZER GIVEN TO THESE A Basic Experiment Set Up Properly: Experimental Group Control Group A CONTROL GROUP is a group of plants that is used as a comparison to the experimental group. The only difference should be that the control group does not get the IV (the new fertilizer), and instead receives the same amount of standard fertilizer. Everything else should be kept equivalent. Original Material by T. Brown 2005

Original Material by T. Brown 2005 FERTILIZER GIVEN TO THESE A Basic Experiment Set Up Properly: Experiment Control If there was only one plant involved it would be called a CONTROL. When there are more than one they are called a CONTROL GROUP. Ideally one should have more than one. Original Material by T. Brown 2005

Original Material by T. Brown 2005 FERTILIZER GIVEN TO THESE A Basic Experiment Set Up Properly: Experimental Group Control Group CONTROLLED VARIABLES sometimes called CONSTANTS are all the things that stay the same between the two groups. Examples include… same sun exposure, same watering amount and times, same type of plant, same starting condition and age of plants, same amount of fertilizer, same temperature, same soil, same size pots, same air ventilation. Original Material by T. Brown 2005

Original Material by T. Brown 2005 FERTILIZER GIVEN TO THESE A Basic Experiment Set Up Properly: Experimental Group Control Group RESULTS are just a factual accounting of the data. A summary of the results is often written in a lab report as data tables, graphs, and narrative summaries. Results may be QUANTITATIVE or QUALITATIVE. Measuring the height of the plants would be quantitative. Original Material by T. Brown 2005

Original Material by T. Brown 2005 FERTILIZER GIVEN TO THESE A Basic Experiment Set Up Properly: Experimental Group Control Group Sometimes the results may not be what you expected. Original Material by T. Brown 2005

Original Material by T. Brown 2005 FERTILIZER GIVEN TO THESE A Basic Experiment Set Up Properly: Experimental Group Control Group Sometimes the results may be unclear or inconclusive. Original Material by T. Brown 2005

Original Material by T. Brown 2005 FERTILIZER GIVEN TO THESE A Basic Experiment Set Up Properly: Experimental Group Control Group In a CONCLUSION you interpret the results as they relate to the hypothesis. In the example above… The results of the experiment supported the hypothesis. Original Material by T. Brown 2005

Original Material by T. Brown 2005 FERTILIZER GIVEN TO THESE A Basic Experiment Set Up Properly: Experimental Group Control Group In the example above… The results of the experiment rejected the hypothesis. Original Material by T. Brown 2005

Original Material by T. Brown 2005 FERTILIZER GIVEN TO THESE A Basic Experiment Set Up Properly: Experimental Group Control Group Use.. The results of this experiment neither supported nor rejected the hypothesis. When the results are unclear. Original Material by T. Brown 2005