Download ppt - SCIENTIFIC METHOD. INTRODUCTION WHAT IS IT? WHY DO WE NEED IT? WHY THE WORD “SCIENTIFIC”? WHAT “METHOD” HAS TO DO WITH IT? SO SHALL WE START?!!

SCIENTIFIC METHOD. INTRODUCTION

WHAT IS IT?

WHY DO WE NEED IT?

WHY THE WORD “SCIENTIFIC”?

WHAT “METHOD” HAS TO DO WITH IT?

SO SHALL WE START?!!

A common misperception of science is that science defines "truth". Science does not define truth, but rather it defines a way of thought. It is a process in which experiments are used to answer questions. This process is called the scientific method and involves several steps:

Steps of the scientific method: 1. Define the problem - This is usually a question. Example: "Does acid rain affect the development of salamanders?" 2. Collect and organize information - Research library information on:

• Salamanders, acid rain, acids and bases, etc. • Sources could include: books, journals, internet articles, etc. 3. Form a Hypothesis (educated guess or tentative explanation) The hypothesis is a statement that can be tested. • Example: "Salamanders that develop under acid rain conditions show a greater number of developmental abnormalities than salamanders that develop in unpolluted waters."

4. Test the hypothesis - EXPERIMENT Controlled experiment - all the conditions are alike except the condition being tested.

• VARIABLE - the one condition that is tested

• The EXPERIMENTAL GROUP is exposed to the variable.

• The CONTROL GROUP is raised under normal conditions, without the variable.

• Only one variable may be tested at a time.

Variables that depend on each other (for example- in the case of gases pressure will depend directly on the volume of the gas) are called dependent variables. So if the variable "a" changes and causes a change in variable "b" then b is said to be dependent on "a". Independent variables are those which do not depend on each other, such as density and area of a liquid.

5. Observe and record data. Measurements are important. Always rely on facts not comparisons. The scientist may use drawings, tables, graphs, diagrams, photographs, written observations, or sound recordings.

6. Drawing Conclusions

•Conclusions are based on DATA (facts)

•Statistics may be used to evaluate data.

•If a hypothesis is proven to be true over and over it may be called a law or principle.

•If a hypothesis seems to be true but is unable to be directly tested, it becomes a theory.

•Theories and laws may have to be replaced as new evidence becomes available.

A conclusion will often lead to another question, which will lead another experiment, which can lead to another conclusion, and on and on. Science is like doing a giant puzzle, with the handicap that you are anunknown number of pieces. Each new scientific fact is a Piece of the puzzle. Each new piece can change the appearance of entire sections of the picture or fit where one did not expect it to. When scientists have an answer to a question they have asked, they share their results with other scientists in papers, magazine articles, lectures, posters or displays at conventions. This way, new puzzle pieces can be checked out, and the fit tested. You will present your results at the science fair in the form of a display.

Theory vs. Law

A theory or law in the world of science is a hypothesis, or many hypotheses, which have undergone rigorous tests and have never been disproved. There is no set number of tests or a set length of time in which a hypothesis can become a theory or a law. A hypothesis becomes a theory or law when it is the general consensus of the scientific community that it should be so. Theories and laws are not as easily discarded as hypotheses.

Lab Activity:

Purpose: To correctly identify the independent and dependent variables.

Title: Fractures in Rollup candy

Science should be fun.. science should be edible..

The Scientific Method

The scientific method is the only scientific way accepted to back up a theory oridea. This is the method on which all research projects should be based. TheScientific Method is used by researchers to support or disprove a theory.


The Scientific Method involves 5 steps: ObservationQuestionHypothesisMethodResult


Observation- You observe something in the material world, using your senses or machines which are basically extensions of those senses.

AH—Look at this!


Question- You ask a question about what you observe. State the problem or question.


Hypothesis- You predict what you think the answer to your question might be.


Method - You figure out a way to test whether the hypothesis is correct. The outcome must be measurable (quantifiable).Record and analyze data.


Result- You do the experiment using the method you came up with and record the results. You repeat the experiment to confirm your results by retesting.


State Conclusion- You state whether your prediction was confirmed or not and try to explain your results.


Test you knowledge byvisiting the Scientific Scenariosand see if you can identifythe steps of the scientific method.