Scientific Method The Way Science Works

Science Science is a method of understanding the natural world. It is characterized by empirical criteria, logical argument, and skeptical review. It is characterized by creativity and is based on change.

Scientific Knowledge and Change Facts, concepts, principles, laws, theories, and models. Scientific knowledge is always changing as our understanding of the natural world improves. Many people think science is a large list of facts. That’s wrong!

Goal of Science The goal of science is to understand the natural world. The goal of technology is to make modifications in the world to meet human needs.

Conducting Experiments

Scientific Method The scientific method is the heart and soul of science!!! An orderly and systematic manner for solving a problem

What is the scientific method? A logical way of solving problems It enables scientists to organize their work Following it helps scientists to be sure of the results at the end of an experiment

Steps of the Scientific Method Problem Research Hypothesis Experiment –Data Conclusion

Problem Once you have observed something, you may have a question about it. A scientific problem is always stated as a question. Ex: Does the amount of water affect how tall a plant grows?

Gathering Information Observations Libraries Experts

Observation An observation is any information you gather through your five senses There are two kinds of observations:

Observations Quantitative observations always involve a number, or quantity Ex: The chalkboard is 6 meters long Qualitative observations do not have a number Ex: The chalkboard is green

Hypothesis An educated guess Should be an answer to the question you posed as your problem Written as an “If...then... “ statement. Ex: If the amount of water increases, then plant height will also increase

An Educated Guess?

Experiment This is for testing your hypothesis Experiments have variables

Variable Something that you change while doing your experiment Ex: If your variable is the amount of water, you may give some plants 1 liter of water every day, and others plants 2 liters of water A good experiment only tests 1 variable at a time

Variables: There are 2 kinds An independent variable is the part of the experiment you are deliberately manipulating. It does not depend on anything else. (Amount of water.) A dependent variable may change when the independent variable is changed. (Plant height.)

Control To verify or regulate by conducting a parallel experiment For Comparison

Experiment Test/Investigate –Plan the investigation or experiment. Decide what to ignore. Clarify. Think. Devise an experiment. –Execute the plan or experiment. Gather materials. Assemble experiment. Observe results. Devise data collection method.

Placebo

Data Information you gather from your experiment Always make a data table before you do your experiment A good data table has: –Labels at the top of each column –Includes the units you are measuring in –Is made with a straight edge

Analyze and Evaluate Repeat or confirm or predict. –Interpret Data. –Does the experiment need to be revised and repeated because it was flawed in some way? –Did the experiment confirm or deny the hypothesis?

Conclusion At the end of your experiment, you make a conclusion based on the data you have gathered.

Conclusion Your conclusion should state whether your hypothesis was “supported” or “not supported” by the data you gathered. It should also include any sources of error (things that may have gone wrong) in your experiment.

How to Remember All This “ Pizza Really Has Extra Delicious Cheese!” Problem Research Hypothesis Experiment Data Conclusion

Review Questions What is an observation? Give an example of a quantitative observation. How should a hypothesis always be written?

Review Questions Name 2 characteristics of a good data table. How many variables should an experiment test at a time? What is the purpose of a conclusion?