2Scientists use experiments to test a hypothesis or answer a question
3Parts of an Experiment QUESTION/PROBLEM What question is being answered, problem solved, or hypothesis tested.For example, “How many drops of water fit on a penny?” Or, how does the side of a penny affect how many drops of water it can hold?
4Controlled Experiments There are two groups in a controlled experiment:1) Control Group: the part of the experiment that is left alone or “natural”. Used to compare back to.
5Controlled Experiments There are two groups in a controlled experiment:2) Experimental Group: the part of the experiment in which a factor or variable is changed.
6Variables are parts of an experiment What is a Variable?Variables are parts of an experiment
7Controlled variables (constants): What is a Variable?Controlled variables (constants):factors in an experiment that are NOT changed.
8Manipulated (independent) variable: What is a Variable?Manipulated (independent) variable:factors in an experiment that are changed.Good experiments have only ONE manipulated variable.
9Responding (dependent) variable: the factor that you are measuring. What is a Variable?Responding (dependent) variable:the factor that you are measuring.
10Parts of an Experiment Hypothesis An educated guess about the results. Always support your idea with a reason! (I think that…because…)What are some hypotheses you can come up with about the penny?Write yours down!
11Parts of an Experiment Materials: Items used during the experiment. What would we need for the penny experiment? Write yours down…
12Parts of an Experiment Procedures: Steps followed during experiment. Write in a numbered listShould be detailed enough that anyone can follow exactly what you did.How many times you are going to do the experiment? It should be written here!
13PracticeWork with your tablemate to practice writing out a procedure for testing the penny experimentBe specific!
14Parts of an Experiment Observations/Data: All the information gathered while performing the experiment.Now, do the experiment! Record your data in the table.
15Parts of an Experiment Results/Conclusions: Analyze your data to determine the final outcome of the experimentWhat do you NOW believe as a result of the experiment or observations?Restate your hypothesis (or at least relate your findings to it)Support your claim with at least 2 pieces of dataUse good explanatory language
16Practice ConclusionWhat should our conclusion be about how many drops of water a penny can hold? Write one for your experiment, using the above guidelines:
17Parts of an Experiment Share your results: Publish your findings so that others may benefit from your work.
19Observations & Inferences Description of objects, eventsMay include data from all five senses (touch/texture, smell, taste, sight, sound)Could be drawings, diagrams, written wordsDo not include opinions.
20Observations & Inferences Drawing conclusions based on observationsOften provide a reason for the event/object being observed.
21Scientific Method Page (Joe & The Birthday Cake) ExampleScientific Method Page(Joe & The Birthday Cake)
22THeories & LawsLay people often misinterpret the language used by scientists. And for that reason, they sometimes draw the wrong conclusions as to what the scientific terms mean. Three such terms that are often used interchangeably are "scientific law," "hypothesis," and "theory."In layman’s terms, if something is said to be “just a theory,” it usually means that it is a mere guess, or is unproved. It might even lack credibility. But in scientific terms, a theory implies that something has been proven and is generally accepted as being true.
23More like a scientific law than a hypothesis. THeoriesMore like a scientific law than a hypothesis.Explanation of a set of related observations or events based upon proven hypotheses.Verified multiple times by detached groups of researchers.One scientist cannot create a theory, he/she can only create a hypothesis.Examples: The theory of evolution, the theory of relativity, and the quantum theory.
24Examples: The law of gravity, the law of thermodynamics. lawsA statement of fact meant to explain, in concise terms, an action or set of actions.Generally accepted to be true and universal, and can sometimes be expressed in terms of a single mathematical equation. Scientific laws are similar to mathematical postulates. They don’t really need any complex external proofs; they are accepted at face value based upon the fact that they have always been observed to be true.Examples: The law of gravity,the law of thermodynamics.
25Both are used to make predictions of events. similaritiesBoth a scientific theory and a scientific law are accepted to be true by the scientific community as a whole.Both are used to make predictions of events.Both are used to advance technology.
26A theory is much more complex and dynamic. DifferencesA theory is much more complex and dynamic.A law governs a single action, whereas a theory explains a whole series of related phenomena.
27An analogy can be made using a slingshot and an automobile. Theories & LawsAn analogy can be made using a slingshot and an automobile.A scientific law is like a slingshot. A slingshot has but one moving part--the rubber band. If you put a rock in it and draw it back, the rock will fly out at a predictable speed, depending upon the distance the band is drawn back.
28Theories & LawsAn automobile has many moving parts, all working in unison to perform the chore of transporting someone from one point to another point. An automobile is a complex piece of machinery. Sometimes, improvements are made to one or more component parts. A new set of spark plugs that are composed of a better alloy that can withstand heat better, for example, might replace the existing set. But the function of the automobile as a whole remains unchanged.
29Theories & LawsA theory is like the automobile. Components of it can be changed or improved upon, without changing the overall truth of the theory as a whole.
30Excerpted from http://wilstar.net/science/ Theories & LawsExcerpted from