SCIENCE The Art of Experimentation What is Science

SCIENCE The Art of Experimentation

What is Science? n A collection of facts that change as new discoveries are made. Gives us a better understanding on what is going on in the world. n Old theories have been replaced with new ones.

Experiments n Every experiment, no matter how unique, share certain characteristics WITH all the others. They all must have: 1. Problem or Question 2. Variables- factors that will influence the outcome of the experiment

Lab Variables n Independent variable (IV) – the factor that you are testing in the experiment. AKA the manipulated variable Ex: Change amount of water a plant receives. n Dependent Variable (DV)– the factor that changes because of the independent variable; it’s the variable you measure Ex: Measure the plant height after two weeks. n Constants/Controlled variables– variables that are the same for both control and experimental groups. Ex: Plant A and B are same type of plant, planted in the same size pot, watered at the same time of day, etc.

Scientific Method

Hypothesis n A reasonable explanation of an observation or experimental result or n A possible answer to a scientific question that can be tested n **based on credible (trustworthy), accurate (correct-based on supported data) and relevant (related to the topic of the investigation) sources of scientific information

Hypothesis writing n Good Examples: Circle the Independent Variable & the Responding (dependent) variable for each. n If Derrick Rose has less than two injuries this basketball season, then the New York Knicks will make it to the playoffs. n If Taylor Swift works in the studio three hours each day, then she will sell 1 million albums this year. n If the each member of Nation Ford Cross Country team eats ½ lb of pasta before their meet, then their individual times will decrease by 1 minute.

Not So good Examples Not So Good Examples: n I think Seattle will win the Superbowl. n Dogs are better pets than cats. n Nation Ford will win the basketball game tonight.

You Try it!! n Length of helicopter blades vs. rotational speed n Length of string telephone vs. clarity of sound n Hours of shopping vs. amount of money spent n Temperature of solution vs. dissolving time of powdered drink mix

Controlled Experiments n Controlled experiments have two groups: A. Control– the group that does not receive the treatment. You use this group to compare how much change if any, you achieved during your experiment. B. Experimental- the group that receives the treatment.

Multiple Trials n Necessary to repeat an experiment at least 2 times. n If you get the same results over and over then your results are considered reliable. This does NOT prove a hypothesis is correct or incorrect, but supports or does not support the hypothesis.

Collecting Data Two Types of Data: 1. Quantitative – numbers (time, temperature, length, mass, etc. ) 2. Qualitative – descriptions, drawings n Both types of data are important in conducting experiments

Examples of Experimental Data A. B.

Displaying Data n TABLE n GRAPH

Line graph n Shows change between variables.

Bar graph n Shows comparisons

Pie graph n Shows parts of a whole or percentages

Graph Requirements n All graphs must have: n Title n Label on each axis with name of variable n Unit on each axis marked off in equal increments