Bell Work Aug 31, 2015 SPI 0807.Inq.1 (Variables and Controls) 1. The number of pigs in a litter is determined by the mass of the mother pig. Name the independent variable and the dependent variable. 2. You water three sunflower plants with salt water. Each plant receives a different concentration of salt solutions. After a two week period, the height is measured. Name the independent and dependent variables. 3. Different rose bushes are grown in a greenhouse for 2 months. The number of flowers on each bush is counted at the end of the experiment. Name the independent and dependent variables.

Review Activity 1)Go ahead and do this… ….If you sit on the right side of the room, go to work station 1 and get a dry erase board, a marker, and a paper towel. Take these with you back to your seat. …If you sit on the left side of the room, go to the tabletop along the purple wall and get a dry erase board, a marker, and a paper towel. Take these with you back to your seat. 2) Then wait silently for additional instructions. Aug 31, 2015 SPI 0807.Inq.1 (Variables and Controls)

SPI 0807.Inq.1 (Variables and Controls) Today's Plan Plan 1) Explain/Discuss bellwork 2) Emphasize objective(s) 3) Review Independent and Dependent Variables 3)Discuss control variables 4) Watch Mythbuster video(s) and identify ind variables WRITE THIS IN YOUR AGENDA! Homework: NONE Science

Silly Thought Silly Thought 02 I spilled some spot remover on my dog… …now he's gone  Random Fun

In an experiment…  …you should only test for ONE key thing at a time When you repeat the experiment…  …only change this ONE key thing This one thing is called… Notes SPI 0807.Inq.1 (Variables and Controls) Independent Variables

Notes SPI 0807.Inq.1 (Variables and Controls) Science What Is A Dependent Variable?  Often called the "responding variable" because it is the response to the factor that was previously introduced  These are the results that you observe after you introduced the independent/manipulated variable  In other words, anything that "changes on its own" while the experimenter is observing it will be a… Also called "Responding Variable"

Notes SPI 0807.Inq.1 (Variables and Controls) Science What Is A Contolled Variable?  In an experiment, the control variable is something that is constant and unchanged.  Further, a control variable strongly influences values; it is held constant to test the relative impact of independent variables.  In other words, if not held constant it will affect your results and make them invalid.

A student conducts an experiment to determine which ink color in ballpoint pens will last the longest before running out. She uses 3 ink colors in 3 ballpoint pens in a series of experiments. (1) Black ink pen, (2) Blue ink pen, (3) Red ink pen) She copies text from her science book. She copies the same text over and over. She writes at the same speed. The room temperature remains the same. She writes on the same kind of paper. The independent variable is the color of the ink A dependent variable is how long the ink last. What is a contol variables in this example? Textbook, same text, same speed, room temp., same kind of paper Notes SPI 0807.Inq.1 (Variables and Controls) Science

Example: A scientist is conducting an experiment to test how sunlight affects plant growth.  She places one corn plant 1 meter away from a sunlamp.  She places one corn plant 2 meters away from a sunlamp.  She places one corn plant 3 meters away from a sunlamp. Corn plant 01Corn plant 02Corn plant 03 What is the controlled variables in this example? Light source, type of plant, water, soil, temperature, humidity The independent variable is the distance from the sunlamp A dependent variable is the plant growth