Scientific Method

Problem or Question Research Hypothesis Procedure Observations Data Conclusion

Hypothesis A possible explanation for observations that relate to a scientific question Must be testable by observation or experiment It is a Scientific “Guess” Example: I think that if I water the plant everyday it will grow.

You use all five of these to gather information Observation Uses all five senses Sight Hearing Touch Smell Taste You use all five of these to gather information

Observations and measurements recorded during an experiment Data Observations and measurements recorded during an experiment

Controlling Responding Manipulated Variables Factors that can CHANGE during an experiment 3 Types of Variables Controlling Responding Manipulated

Controlled Variable The variable that stays the SAME Example: You have two plants that are both in the same pot, with the same amount of soil, the same amount of seeds and have the same amount of water. You place one in front of the window and the other in a closet. After two weeks you measure to see the growth of each of the plants.

Manipulated Variable The variable that the scientist CHANGES Independent variable, Found on the x-axis Example: You have two plants that are both in the same pot, with the same amount of soil, the same amount of seeds and have the same amount of water. You place one in front of the window and the other in a closet. After two weeks you measure to see the growth of each of the plants.

Responding Variable The variable that the scientist Measures Dependent variable, Found on the y-axis Example: You have two plants that are both in the same pot, with the same amount of soil, the same amount of seeds and have the same amount of water. You place one in front of the window and the other in a closet. After two weeks you measure to see the growth of each of the plants.

control or control group controlled variables -V- control or control group The control or control group is used to compare your experimental results. It is the group or item that the scientist does nothing to. Example – test 2 types of car wax. You wax two spots on the car and leave one spot unchanged (no wax is applied).

What are the controlled variables? Battery, wire, type of nail None of these items were changed

Let’s Practice! Students of different ages were given the same jigsaw puzzle to put together. They were timed to see how long it took to finish the puzzle.

What is the Independent Variable? Ages of the students Different ages were tested by the scientist

What was the dependent variable? The time it took to put the puzzle together The time was observed and measured by the scientist

What was the controlled variable? Same puzzle All of the participants were tested with the same puzzle. It would not have been a fair test if some had an easy 30 piece puzzle and some had a harder 500 piece puzzle.

Try Another An investigation was done with an electromagnetic system made from a battery and wire wrapped around a nail. Different sizes of nails were used. The number of paper clips the electromagnet could pick up was measured.

What is the independent variable? Sizes of nails These were changed by the scientist

What is the dependent variable? Number of paper clips picked up The number of paper clips observed and counted (measured)

Results There are many different ways to organize the data into your results Bar Graph Data Table Line Graph Circle Graph

Compare Hypothesis to the Data How to begin…. Conclusion Compare Hypothesis to the Data How to begin…. According to my data, my hypothesis was right or wrong because…. I think this happened because….If I were to do this experiment again I would…..

Scientific Law A statement that describes what scientists expect to happen EVERY time under a particular set of conditions. Example: Law of gravity …what goes up will come down…(happens every time)

Scientific Theory A well-tested idea that explains and connects a wide range of observations. Can be changed because of new evidence Example: My theory is that everyone in this class will get an A+ on their first test