The Scientific Method Organized Common Sense Scientific Method

The Scientific Method Organized Common Sense

Scientific Method ¨ The scientific Method is a method of answering scientific question

Steps in the Scientific Method 1. State the problem 2. Form a hypothesis 3. Test the hypothesis 4. Organize data 5. Form a conclusion 6. Replicate work

Stating a Problem ¨THIS IS NOT A PERSONAL PROBLEM!! ¨The problem is the scientific question ¨Do plants need water to grow?

Researched hypothesis ¨ A hypothesis is a possible answer (educated guess) ¨ Based on prior knowledge, observations and research ¨ Written in an “If… then…” format ¨ If plants get water, then they will grow. – Is this true? – We will find out by testing

Test the Hypothesis This may be done through: ¨ Observations ¨ An experiment ¨ Before designing and running an experiment, we must first determine the independent and dependent variables.

How are Experiments run? ¨ Independent variable (IV) is the variable that is purposefully changed by the experimenter. – It is the one factor (cause) that the experimenter wants to test – On a line graph, the IV is plotted on the X-axis. ¨ Example: If plants get water, then they will grow. – IV: the amount of water given to plants

How are Experiments run? ¨ Dependent variable (DV) is the variable that responds or changes during the experiment. – On a line graph, the DV is plotted on the Yaxis. ¨ Example: If plants get water, then they will grow. – DV: the growth of the plant.

How are Experiments run? ¨ You must have constants – Factors in an experiment that are kept the same throughout the experiment in both the control group and the experimental group ¨ Example: I will have three plants of the same species, given the same amount of light, planted in the same soil, given the same nutrients, and receive the same amount of air.

How are Experiments run? ¨ You must have a control and experimental group. ¨ Control is the standard that is used to compare with the experimental group. The independent variable is missing and is often the “normal” situation. ¨ Example: The plant that receives NO water (variable is missing).

How are Experiments run? ¨ Experimental group is the test group, in which all conditions are kept the same except for the single condition being tested. ¨ Example: There are several plants in the experimental group. – One plant gets 5 mls of water – One plant gets 10 mls of water – One plant gets 15 mls of water

Organize Data ¨ Data is information collected during experiment is recorded in an organized fashion. ¨ Data table, pictures, and graphs – Pie graphs show percent – Bar graphs show relationship between IV and DV – Scatter graphs are used to discover how one thing might affect something else

Graphing Rules 1. Include with your graph: - Title - Label for the X and Y axis (including units) 2. Use even numerical spacing (2, 4, 6, etc. ) 3. Use even graphical spacing (graph paper) 4. Be accurate and neat 5. Use rulers, protractors and colors (create a legend or key if necessary)

How do I label the X and Y axis? ¨ For line graphs: – the dependent variable is on the y axis – the independent variable is on the x axis • For bar graphs: - the names of items go on the x axis - the amounts go on the y axis

How do I label the X and Y axis? ¨ Example:

Form a Conclusion ¨ The conclusion tries to explain the data. A good conclusion will: – Analyze and explain the data – Reference the data to support any conclusions made – Explain why this information would be beneficial – Explain any possible errors in the experiment – Recommend other experiments that can be done to understand the topic better

What is a Theory? ¨ A theory is a unifying explanation agreed upon by most scientists developed by analyzing data collected by many experiments over a period of time.

You try ¨Think of a question or a problem that you encountered ¨Try to solve it by using the scientific method ¨Write this in your notes. Use headings.