Scientific Method and Measurement

Ms. MezzettiBiology

Lynn English High School

Scientific Method

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Scientific MethodThe word science is derived from a Latin verb meaning “to know”.The scientific method is used to solve problems in science and in everyday lifeCan you give an example of how you have used the scientific method?

Steps of the scientific method1. Make an observation:

Using our 5 senses we make observations

2. Ask questions: Based on an observation we ask questions as to what we would like to know

3. Collect Data: Before we can form a hypothesis, we need to collect some information.

Scientific Method4. Make a hypothesis:

Using our observations and collected data a hypothesis is usually an “if..then” testable statement of what we think is true

5. Experiment: Used to test the hypothesis and prove it correct or incorrect.

Experiment

A controlled experiment has a control group which stays the same and an experimental group where one factor is changed-known as the independent variableThe factor that is being measured is known as the dependent variable

Analyze results

6. Analyze: Do the results/data from the experiment support the hypothesis

Data can be models, graphs or tables. It can be qualitative-color change; quantitative which is numbers

Drawing conclusions

7. Draw conclusions: Is the hypothesis correct? . If not, you need to go back and revise the hypothesis and experiment again.

8. Communicate results: After many trials with repeated results, it is important to communicate results. There must be many trials before a theory (thought to be true) or law(fact based on repeated experimentation) can be stated.

Scientific Measurement

Scientists use Systèm International d’Unités (Internal System of Measurements), commonly called SI.This allows scientists to have a universal way to communicate their results

The Seven Fundamental Base Units

1. Meter (m) – length2. Kilogram (kg) – mass3. Second (s) – time4. Ampere (A) – electric current5. Kelvin (K) – thermodynamic temperature6. Mole (mol) – amount of substance7. Candela (cd) – luminous intensity

The Metric System

The metric system uses the same prefixes.Common prefixes are:

kilo = 1000 centi = 1/100th milli = 1/1000th

1 meter = 100 centimeters= 1000 millimeters

Derived Units