Theory vs Hypotheses

A hypothesis is an educated guess. A hypothesis can become a theory.

A theory has: undergone extensive testing by various scientists AND is generally accepted as being an accurate explanation of an observation. This does NOT mean the theory is correct; only that current testing has not yet been able to disprove it, and the current evidence appears to support it.

In other words… A theory has been tested many times by many scientists. It is a proposed explanation for a wide range of observations– Theories are never proven

Theories, no matter how well accepted, are always subject to change as new knowledge comes to light.

PIT STOP (Write in complete sentences) 1. What is the difference between a hypothesis and a theory? A hypothesis is … while a theory is…

A description of nature that can be used to make predictions Scientific Models A description of nature that can be used to make predictions

Models can be changed and refined

All models have limitations — no model can possibly explain every detail of a scientific phenomena

The Scientific Method

What is the scientific method? One (of many) process(es) used by scientists to solve problems

All scientific understanding is based on observing- using one or more of the 1) 5 senses Sight, Hearing, Taste, Touch, Smell

WHAT ARE YOU TRYING TO FIND OUT? 2. QUESTION OR PROBLEM WHAT ARE YOU TRYING TO FIND OUT?

3. RESEARCH FIND OUT WHAT THERE IS TO KNOW ON THE SUBJECT…. GET BACKGROUND INFORMATION

WHAT YOU THINK MAY HAPPEN 4. MAKE A HYPOTHESIS AN EDUCATED GUESS… WHAT YOU THINK MAY HAPPEN

Design an experiment to test the hypothesis 5.EXPERIMENTATION Design an experiment to test the hypothesis

All experiments have 2 types of variables: 1. independent variable- what is being changed/tested 2. dependent variable – what ever you are measuring

Your experiment must include only one INDEPENDENT VARIABLE. **The DEPENDENT variable depends on the independent variable

Example: You are measuring the effects of caffeine on your heart rate. You give one group caffeine and another group water. The heart rate (what you are measuring) depends on whether you had caffeine or not (what is being changed between the groups/what is being tested) The caffeine is the independent variable, the heart rate is the dependent variable

The experiment must also include a CONTROL GROUP. The CONTROL is set up exactly like the one with the variable, but it does not contain the variable. They are factors that stay the same throughout the experiment

In the above example is there a control group? Yes, the group without caffeine What would you do to create a control group? Take away the independent variable

PIT STOP (Write in complete sentences) 1. What is the difference between the independent variable and the dependent variable of an experiment? The I.V. is … while the D.V. is…

6. COLLECT DATA/ Analysis Ways to collect data: Record visual observations, take pictures, measurements, graph, data table, etc.

7. CONCLUSION Determine what happened and why… Were your results reliable?

A statement that supports or rejects your hypothesis 7. CONCLUSION A statement that supports or rejects your hypothesis