Finding the Control Variable
This, or these variables, is kept constant so that any change is due to the independent variable.
What is controlled variable?
Is the thing that will change, that you intend to measure.
What is dependent/respondent variable.
You decide you want to compare which music makes you fall asleep faster. Week 1 you listen to rock music. Week 2 you listen to country music. Week 3 you listen to classical music. What is a variable that needs to be controlled or kept constant?
What is music at same volume, same time listening, etc.
Is the size of fish affected by the depth of the ocean they live? What would be the IV?
What is depth of ocean.
A group of scientists test the behavior that women find men without earrings more attractive than men with earrings. What is the IV?
What is men wearing earrings.
Bart believes that mice exposed to radio waves will become extra strong. He has two groups of ten mice. He places group A near a radio for 5 hours. Group B that had not been exposed to radio waves. To test the hypothesis he placed a wood block to block the door to the mice food. After 5 hours he found that 8 out of 10 of Group A mice were able to push the block away. 7 out of 10 of Group B mice were able to do the same. What are some variables he needs to control or keep constant?
Same breed/size of mice, same type/amount of food, etc.
Is photosynthesis production of starch faster when plants are exposed to different amounts of light? What would be the DV?
What is amount of starch produced.
Children who entered kindergarten at age 5 were compared with children who entered kindergarten at age 6 on measures of academic achievement taken at grade 5. Results indicate that children who entered kindergarten at age 6 scored higher on standardized tests than those kids that entered at age 5. What is the DV?
What is score on standardized test.
You want to see if students do better on a test if they study with music. You divide up one class into 2 groups of 15 students. Group A listens to music while studying their notes for 1 hour a night. Group B studies their notes with no music for 1 hour a night. After two weeks, a comprehension test was given to all students after they had studied their notes in silence or with music turned on.
What is 4--two weeks, 1 hour a night, 2 groups of 15 students, test
Pea plant clones are giving different amounts of water for three-week period. The first pea plant receives 400 milliliters a day. The second pea plant receives 200 milliliters a day. The third pea plant receives 100 milliliters a day. The heights of the pea plants are recorded daily. Controlled variables?
Same type/clones of pea plants, same amount of light, soil, etc.
A researcher wants to investigate the types of social behavior that develops in children in day care depending on the amount of time the child spend in day care. What is the IV?
What is time spent in daycare.
When multiple experiments have been conducted, data is analyzed and the results are shared with others.
What is communicating results?
The design of a good experiment that only tests one variable at a time.
What is has only one independent variable, a measurable/observable dependent variable, and all other variables controlled or kept the same/constant?
Three redwood trees are kept at different humidity levels inside a greenhouse for 12 weeks. One tree is left outside in normal conditions. The heights of the trees are measured once a week. IV ? DV ?
What is IV-different humidity; levels DV-Height of redwood trees?
Explains a natural phenomenon, a explanation of many different hypothesis that have been tested widely.
What is a theory?