Chapter 1.2, Defining Science  Pure Science  research that adds to the body of scientific knowledge  has no practical use  Applied Science (Technology)  the practical application of scientific knowledge

Defining Science PURE  human genetics  polymer science  atomic theory  study of the human ear APPLIED  DNA fingerprinting  Lycra ® spandex  nuclear weapons  hearing aids

Problem-Solving 1. Identify the problem.  What do you know?  What do you need to know? 2. Plan a strategy.  Look for patterns.  Break the problem into smaller steps.  Develop a model (representation of an object or event, globe = small scale of earth)

Problem-Solving 3. Execute your plan. 4. Evaluate your results.  Did you solve the problem?  Is your answer reasonable? Identify - Plan - Execute - Evaluate

Scientific Method  Hypothesis - testable prediction (proposed answer to a question)  Construct a Hypothesis: A hypothesis is an educated guess about how things work:  "If _____[I do this] _____, then _____[this]_____ will happen.“ (ex: popcorn, skip to slide16)  You must state your hypothesis in a way that you can easily measure, and of course, your hypothesis should be constructed in a way to help you answer your original question.

Scientific Method  Theory - explanation of “why”  based on many observations & experimental results  Scientific Law - prediction of “what”  describes a pattern in nature

Scientific Method Theories and laws are well-accepted by scientists, but... They are revised when new information is discovered. THEY ARE NOT SET IN STONE!

Scientific Method 1. Determine the problem. (by making observations, asking a question, doing research 2. Make a hypothesis. 3. Test your hypothesis. 4. Analyze the results. 5. Draw conclusions.

Scientific Method

1. Determine the problem. When the Titanic sank, what happened to the water level on shore? 2. Make a hypothesis. The water level rose. The water level dropped. The water level stayed the same.

Scientific Method 3. Test your hypothesis. How could we test our hypothesis? 4. Analyze the results. What happened during our test? 5. Draw conclusions. Was our hypothesis correct? Is further testing necessary?

Experimental Design  Experiment - organized procedure for testing a hypothesis  Key Components:  Control Experiment - standard for comparison (independent variable eliminated or set at a standard value)  Independent variable - keeps other factors constant, only one variable changes at a time  Repeated trials - for reliability

Experimental Design  Types of Variables  An independent variable is the variable that is changed in a scientific experiment  Changed to test their dependent variable -what the experimenter measures / tests in a scientific experiment  A change in the independent variable directly causes a change in the dependent variable

Example  A scientist is testing the effect of light and dark on the behavior of moths by turning a light on and off. The independent variable is the amount of light and the moth's reaction is the dependent variable  A change in the independent variable (amount of light) directly causes a change in the dependent variable (moth behavior)

Experimental Design  Hypothesis: Storing popcorn in the freezer makes it pop better.  Control: a group of subjects closely resembling the treatment group BUT NOT receiving the different factor under study and thereby serving as a comparison group when treatment results are evaluated Popcorn stored at room temp.

Experimental Design  Independent variable: Storage temperature  Constants: Popcorn brand Freshness Storage time Popper

Experimental Design -Independent Variable: Storage temperature -Dependent Variable: Number of un-popped kernels