Using the Scientific Method

 

The scientific method is an approach used by scientists to answer questions about the natural world.

*The scientific method is bases upon evidence, rather than belief. This distinguishes science from faith.

* A scientist is suitably skeptical of anything but good evidence.

I. Identify the Problem to be solved/ or the question to be answered.

II. Observation; This is used throughout the process of the Scientific Method.

A. Direct; using one or more of the senses (sight, sound, taste, touch, or smell).

B. Indirect; using an instrument in addition to the senses.

1. Use of microscope or telescope to see things beyond the normal range of human sight.

2. Reading a thermometer to know the actual temperature of a substance.

III. Form a Hypothesis; A possible solution to the problem or answer to the question.

*Your hypotheses can be, and often are incorrect.

*Your hypothesis must be something that you can test, or science cannot help you decide whether it is correct or incorrect.

*Usually, before a scientist makes a hypothesis, they have some idea what the answer to their question might be.

IV. Experiment; Testing your hypothesis to see if it is correct.

A Parts of an experiment;

1. Control: this is kept under “normal” conditions during

and experiment, and is used to make a comparison to see if anything has occurred.

2. Constants: the things that remain the same throughout the

experiment.

*a. using the same amount of water (any substance) in all of the tested samples as well as the control.

*b. doing tests at the same temp. and keeping the control at the same temp.

3. Variable; the thing that is changed, or measured in an experiment. This

should be a single factor.

a. Independent (manipulated) variable; The single factor, or condition in a controlled experiment that is changed.

b. Dependent (responding) variable; The measurable condition that results from changing the independent variable.

B. Data; Information collected during experimental trials.

1. Quantitative; appear as numbers. *ex. There are 300 wolves in Yellowstone Park.

2. Qualitative; descriptive, and involve characteristics that can’t be counted.

*ex. The wolves in Yellowstone Park appear to be very healthy.

V. Analysis; After multiple trials, you should be able to look at the data that you have gathered to

determine whether or not your hypothesis can be supported.

Graphing your data will allow you to see the results of your experiment in a format that is easy to read and analyze.

There are several types of graphs used, for illustrating data in a variety of ways.

Circle graph(pie chart) are used to illustrate a part to whole relationship.

Of the whole atmosphere, oxygen is a part at 21%.

A bar graph is used to make comparisons.

A line graph

is used to illustrate a trend.

M I X

D

R

Y

ependant

esponding

-axis

anipulative

ndependant

-axis

Your X-axis might show each year, for a 20 year period from Yellowstone Park.

Your Y-axis might show the change in wolf population during this time.

← D comes before↓ M

VI. Conclusion; After verifying your results, form a conclusion stating whether or not your hypothesis has,

or has not been supported. It is important to share this

information with other scientists. Then, they can verify your results by repeating your experiment.

*If the same results occur again, this provides support for your original conclusions. If your original idea was flawed, this keeps others from repeating your mistakes.

*In science, there are exceptions to following these steps in the scientific method.

Some situations may dictate that this strategy is not necessary to follow. In addition, scientist do not verbally state each step of “the method” as they are solving problems.

It is simply a logical and methodical way to solve problems.

Scientific Theories, and Laws

*Scientific theories are based on more than just a wild idea, or an unsure guess.

*In science, if a large body of evidence supports a hypothesis over a long period of time, it becomes a theory.

*A theory is an explanation for a natural phenomenon that is supported by lots of scientific evidence.

*A theory often becomes the dominant view amongst scientists. Even so, a theory

isn’t considered the absolute truth. New evidence may cause a theory to be revised, or replaced.

*Certain facts in science are recognized as scientific laws. For example, the fact that a dropped apple falls to the earth is an illustration of the law of gravity.