Scientific Method Interactive Notebook Notes

Using the Scientific Method Science begins with an “observation” : Nitrogen is an essential nutrient that all living organisms, including plants, need to make amino acids which in turn makes proteins. Often gardeners and farmers can be seen using nitrogen fertilizer on their plants.

Step 1: Observation leads to a QUESTION: Does nitrogen fertilizer affect plant height? QUESTION leads to a possible prediction: Nitrogen fertilizer increases plant height

LETS TEST THIS!!! Does nitrogen fertilizer affect plant height? Step 2: Form a Hypothesis Hypothesis: A hypothesis is ALWAYS written in an if, then statement If plants are given nitrogen fertilizer, then they will grow taller. Educated Guess or Answer to your question

Identifying variables - Not a step but a MUST Independent Variable: Dependent Variable: Controlled Variables: Factors in an experiment that a scientist PURPOSELY Changes (manipulated) Factors in an experiment that a scientist WANTS TO MEASURE and is changed by the independent variable. Factors that scientists purposely keep the SAME AKA:Constants

Does nitrogen fertilizer affect plant height? Independent Variable: Dependent Variable: Controlled Variables: Whether or not the plants receive the nitrogen fertilizer. Plant Height Type of plants, amount of water/fertilizer, amount of weeks tested, amount of sun received

Step 3: Set up Experiment Experimental group vs. Control Group Experimental Group Group that receives the variable being tested. This group is then compared to CONTROL GROUP. Control Group Group that DOES NOT receive the variable being tested. This group is then compared to EXPERIMENTAL GROUP.

Does nitrogen fertilizer affect plant height? Experimental group vs. Control Group Experimental Group The group of plants that RECEIVE the nitrogen fertilizer. Control Group The group of plants that DO NOT RECEIVE the nitrogen fertilizer.

Step 4: Recording/Analyzing Results and Data: Here are the plants after 3 weeks. Measure each plant’s height using a ruler, record the data in the table, and then create a bar graph. Next, analyze your results, what did you find?

Recording Data GroupPlant NumberPlant Height (cm) Experimental Group With Nitrogen Fertilizer Plant 13.2 Plant 24.3 Plant 35.5 Plant 44.8 Plant 53.0 Control Group Without Nitrogen Fertilizer Plant 12.4 Plant 21.6 Plant 32.7 Plant 41.4 Plant 51.8

Record Data

Analyzing Data Put your data in words. Ten Plants were used in this experiment. The 5 tallest plants all came from the experimental group (received nitrogen fertilizer). The 5 shortest plants all came from the control group (did not receive nitrogen fertilizer).

Step 5: Conclusions Summarize your results. Indicate whether or not your data supported or rejected your hypothesis. Did your experiment have any errors or complications? What were they? Suggest any changes in the experimental procedure(or design) and/or possibilities for further study.

Example Conclusion The results of the experiment supported the hypothesis that if plants given nitrogen fertilizer then they would grow taller than those not given it. The experiment went smoothly with no errors or problems. In the future I would like to test various amounts of fertilizer to find out what amount makes plants grow at their maximum capacity.