P4 THE SCIENTIFIC METHOD

what if… when I… how do… Find a general topic that interests you and write down the question that you want to answer.

Ask a Question The scientific method starts when you ask a question about something that you observe: How, What, When, Who, Which, Why or Where? Observation means using one or more of your senses to try and understand or learn about something. But in order for the scientific method to answer the question, it must be about something that you can measure, preferably with a number.

Ask a Question Begin with observations Observations are not inferences Use all five senses Observations are not inferences Gather Information Research Ask questions

Do Background Research So that you can design an experiment You need to research what techniques and equipment might be best for investigating your topic. Rather than starting from scratch, savvy investigators want to use their library and internet research to help them find the best way of doing things.

Construct a Hypothesis “If [ I do this ]_, _[ this]__will happen.” A hypothesis is an educated guess about how things work. It is a tentative statement that proposes a possible explanation to some phenomenon or event. You must state your hypothesis in a way that you can easily measure and, of course, your hypothesis should be constructed in a way to help you answer your original question. Write the problem statement (using the phrase, “To find out”)

Construct a Hypothesis A useful hypothesis is a testable statement which may include a prediction. The keyword is testable. So you need to perform a test of how 2 variables might be related. You test the variables in a real experiment. There has to be a tentative relationship stated between the variables. Variables are quantities whose values can change.

Construct a Hypothesis Variables To construct a hypothesis, you need to know 2 variables, independent and dependent variables. The independent variable is the one you, the ‘scientist’ controls and the dependent variable is the one you observe or measure the results.

Identifying Variables Let’s try to identify the variables using the examples of hypotheses below: 1. If drinking soft drinks is related to tooth decay, then people who consume large amounts of soft drinks will have a higher frequency of tooth decay. (Independent variable:? Dependent variable:?)

Identifying Variables 2. If leaf colour change is related to temperature, then exposing plants to low temperatures will result in changes in leaf colour. (Independent variable:? Dependent variable:?)

Test with an Experiment Your experiment tests whether your hypothesis is true or false. It is important that your experiment is a fair test. You conduct a fair test by making sure that you change only one variable at a time while keeping all other variables the same.

Test with an Experiment There are two groups in an experiment: The Control Group The Experimental Group The Experimental Group receives the addition of the variable being tested. The Control Group does not.

Test with an Experiment Conducting the experiment once is called a Trial. Repeating an experiment several times is making Multiple Trials. You should repeat your experiment several times to make sure that your first results weren’t just an accident. The scientist then takes an average of the results.

Analyze Data Once your experiment is complete, collect your measurements and analyze them to see if your hypothesis is true or false. Draw Conclusions A Conclusion is a statement based on the results of the experiment. The conclusion may or may not support the hypothesis.

Analyze Data If false or partially true, you think and try again by going back to constructing a hypothesis. (Scientists often find that their hypothesis was false and if so, they will construct a new one. Even if the hypothesis was true, they may want to test it in a new way!)

Analyze Data If true, go to the The Scientific Method If true, go to the next step which is communicate your results. Copyright 2007 Kenneth Lafferty Hess Family Charitable Foundation

Analyze Data A Graph is a diagram that shows the relationship of one variable to another. A graph makes interpretation and analysis of data easier.

Analyze Data Three Basic Graph Types A Line Graph best represents “change over time” data. A Bar Graph should be used for “one-time” measurements. A Pie Graph can clearly display percentages or “parts of a whole”.

Analyze Data

Analyze Data

Analyze Data

Analyze Data Important Notes on Graphs! The axes display the range of the data, not the data itself. On the axes, gridlines must represent equal distances. The larger the graph, the better the representation of the data.

Communicate Results To complete your project, you will communicate your results to others in a final report and/or a display board. Professional scientists do almost exactly the same by publishing their final report in a scientific journal or by presenting their results on a poster at a scientific meeting.

Communicate Results Valid Results are those that measure what they were intended to measure. Reliable Results are those that can be repeated.

THE SCIENTIFIC METHOD The scientific method is a way to ask and answer scientific questions by making observations and doing experiments.

Acknowledgements: Website http://www.sciencebuddies.org/