The Nature of Science

What is Science? The goal of science is to understand the world in which we live!

The Scientific Method No set order!

Observation Employing your five senses to perceive objects or events

Asking a Question Based on observations; one or more questions are generated Questions should be meaningful and testable! You must be able to create an EXPERIMENT based on that question

Hypothesizing Possible explanation for what you think will happen in a certain situation Based on research or observations! A clear statement that can be tested Hypothesis = a statement that says what scientists think will happen when an experiment is tested Needs to be a clear statement and something that can be tested and measured Ex. Room temperature water will make plants grow taller than boiling water.

Experimenting Testing a hypothesis or prediction by gathering data under controlled conditions Based on a comparison of a control group with an experimental group What are we testing here? Can be simple!

Parts of Your Experiment Independent variable = factors you change Dependent variable = the result of what you changed Constants = factors you keep the same DRY MIX Example: want to know if bigger engines make cars go faster Independent variable = size of engine Dependent variable = speed of car Constants = same track, same car, etc.

Parts of Your Experiment Control Group: An experiment where one group receives no treatment Used for comparison Experimental Group: Group that has had the independent variable added to it Example continued Control group = speed of car that has a normal size engine (size not changed) Experimental group = car with bigger engine

Collecting Data Data = evidence Includes all measurements & observations made during the experiment Repeat trials and average your results to reduce random error

Types of Data Quantitative data = results that are measured and described with numbers Examples: 5 mph (speed), 2 feet (length) Qualitative data = results that are described in words; from our five senses Examples: color, texture

Organizing Data Involves placing observations and measurement (data) in order Graphs, charts, tables, or maps

Analyzing Data Collected and organized data must be analyzed Process of determining whether data are reliable or whether they support or do not support a hypothesis or prediction

Forming a Theory supported with much experimental data a broad and comprehensive statement of what is thought to be true

Communication Share the results of their studies with other scientists Publish findings in journals or at scientific meetings Subject to examination and verification by other scientists = peer reviewed Allows scientists to build on the work of others Can’t trust findings if it hasn’t been peer reviewed!

Let’s practice together! Patrick believes that fish that eat food exposed to microwaves will become smarter and would be able to swim through a maze faster. He decides to perform an experiment by placing fish food in a microwave for 20 seconds. He has the fish swim through a maze and records the time it takes for each one to make it to the end. He feeds the special food to 10 fish and gives regular food to 10 others. After 1 week, he has the fish swim through the maze again and records the times for each. Hypothesis? Fish that eat food exposed to microwaves will be able to swim through a maze faster. Control group? 10 fish that get regular food Independent variable? Type of food Dependent variable? Smartness Conclusion? They all did a little better the second time, so microwaved food doesn’t make a significant difference Next steps? New hypothesis?