Name: ______Date:______Hr:______
Three Examples of Variables:
1. Apple trees that receive the most water will produce the largest apples.
The amount of water can be changed to determine its effect on the size of the apples grown.
Independent Variable-amounts of water used
Dependent Variable-size of the apple
Constants-type of water, time of day watered, water delivery system, temperature of water, type of tree, size of tree,growth measurements completed at the same time
2. Students will score better on spelling tests by increasing the number of minutes each student studies.
The amount of time can be changed to determine its effect on the spelling scores.
Independent Variable-amount of time students study
Dependent Variable-score on individual spelling tests
Constants-age of student, gender of student, time of test, test giver, study method
3. An electromagnet will pick up more nails if more batteries are put in the circuit.
The number of batteries can be changed to determine its effect on the electromagnet.
Independent Variable-number of batteries in a circuit
Dependent Variable-number of nails the electromagnet picks up
Constants-type of battery, size and amount of wire, type of connection, type of circuit, size and type of paper clips,procedure for picking up the clips.
Questions for today’s assignment
- A researcher was interested in the effects of reward on intrinsic motivation. Some children were told that they would be given a special award for drawing with magic markers (an activity they already enjoyed). Other children were simply asked to draw with the magic markers. One week later, the children were unobtrusively observed for how much time they spent drawing with the markers. The children who expected and received a reward for drawing with the markers were less likely to draw with them later.
Experimental Design Diagram
Title: The effect of the ______on the ______.
(Independent Variable) (Dependent Variable)
Hypothesis: If the ______
(Independent Variable) (Describe how it will be changed)
thenthe ______will ______.
(Dependent Variable) (Describe the effect)
Independent Variable / Levels of IV / # Trials /Dependent Variablelow / 1.
2.
3.
middle / 1.
2.
3.
high / 1.
2.
3.
Independent Variable (IV):
Dependent Variable (DV):
Control:
Constants (C):
2. In an investigation of the fundamental attribution error, subjects were given a speech to read that either favored or opposed Fidel Castro, the communist leader of Cuba. Subjects were told that the speech was written by a student who had been assigned to the position taken in the paper (that is, the student writing the speech had no choice on which position to take). Nevertheless, subjects believed that the student who wrote the pro-Castro speech had positive attitudes toward Castro, while subjects who read the anti-Castro paper believed the writer had negative attitudes toward Castro.
Experimental Design Diagram
Title: The effect of the ______on the ______.
(Independent Variable) (Dependent Variable)
Hypothesis: If the ______
(Independent Variable) (Describe how it will be changed)
thenthe ______will ______.
(Dependent Variable) (Describe the effect)
Independent Variable / Levels of IV / # Trials /Dependent Variablelow / 1.
2.
3.
middle / 1.
2.
3.
high / 1.
2.
3.
Independent Variable (IV):
Dependent Variable (DV):
Control:
Constants (C):
3. Within a classroom setting, subjects were asked to listen to a guest instructor. All subjects were given a description of the instructor. Some subjects read a description containing the phrase “People who know him consider him to be a rather cold person...”, while other people read a description where the word “warm” was substituted for the word cold (otherwise, the descriptions were identical). After the lecture, subjects were asked to rate the instructor. Subjects who were told the instructor was warm gave him more favorable ratings compared to subjects who were told that the instructor was cold.
Experimental Design Diagram
Title: The effect of the ______on the ______.
(Independent Variable) (Dependent Variable)
Hypothesis: If the ______
(Independent Variable) (Describe how it will be changed)
thenthe ______will ______.
(Dependent Variable) (Describe the effect)
Independent Variable / Levels of IV / # Trials /Dependent Variablelow / 1.
2.
3.
middle / 1.
2.
3.
high / 1.
2.
3.
Independent Variable (IV):
Dependent Variable (DV):
Control:
Constants (C):
4. Subjects watched a videotape of a woman taking an SAT-like test. In all cases, she correctly answered 15 out of 30 questions. But subjects who observed a pattern of initial success followed by failure perceived the woman as more intelligent than did those who observed the opposite pattern of failure followed by success.
Experimental Design Diagram
Title: The effect of the ______on the ______.
(Independent Variable) (Dependent Variable)
Hypothesis: If the ______
(Independent Variable) (Describe how it will be changed)
thenthe ______will ______.
(Dependent Variable) (Describe the effect)
Independent Variable / Levels of IV / # Trials /Dependent Variablelow / 1.
2.
3.
middle / 1.
2.
3.
high / 1.
2.
3.
Independent Variable (IV):
Dependent Variable (DV):
Control:
Constants (C):
5. Subjects read about a woman who used a particular title, and then rated her on a number of traits. When the woman used the title Ms. rather than Miss or Mrs., she was assumed to be more assertive, achievement oriented, and dynamic, but also cold, unpopular, and unlikely to have a happy marriage.
Experimental Design Diagram
Title: The effect of the ______on the ______.
(Independent Variable) (Dependent Variable)
Hypothesis: If the ______
(Independent Variable) (Describe how it will be changed)
thenthe ______will ______.
(Dependent Variable) (Describe the effect)
Independent Variable / Levels of IV / # Trials /Dependent Variablelow / 1.
2.
3.
middle / 1.
2.
3.
high / 1.
2.
3.
Independent Variable (IV):
Dependent Variable (DV):
Control:
Constants (C):
6. People were randomly approached on the street by a stranger and were asked to use his camera to take a picture of him for a school project. For half of the subjects, the camera didn’t work--the stranger looked concerned, said that the camera was rather delicate, asked the subject if he touched any of the dials, and announced that it would have to be fixed. For the other half of the subjects, the camera worked fine. Further down the street, a woman dropped a file folder of papers. Forty percent of the subjects who had no broken-camera experience helped the woman pick up her papers, while 80% of the subjects who were led to believe that they broke the woman’s camera helped.
Experimental Design Diagram
Title: The effect of the ______on the ______.
(Independent Variable) (Dependent Variable)
Hypothesis: If the ______
(Independent Variable) (Describe how it will be changed)
thenthe ______will ______.
(Dependent Variable) (Describe the effect)
Independent Variable / Levels of IV / # Trials /Dependent Variablelow / 1.
2.
3.
middle / 1.
2.
3.
high / 1.
2.
3.
Independent Variable (IV):
Dependent Variable (DV):
Control:
Constants (C):
Your hypothesis can even TELL you what your variables are!
Ex. If I drink Mountain Dew before bed, then I will not sleep very much.
IV: Drinking Mountain Dew
DV: the amount of sleep
Use this hypothesis to identify the variables:
7. If I leave all the lights on all day, then my electric bill will be expensive.
IV: ______
DV: ______
8. If I brush my cat more, then there will be less fur on my furniture
IV: ______
DV: ______
9. Elizabeth wanted to test if temperature affected how fast milk goes bad and curdles. She left milk in a room temperature closet, a fridge, and a oven that was turned on low heat. She then measured how rotten the milk was after 10 days.
IV: ______
DV: ______
10. The farther a ball drops, the higher it will bounce.
IV: ______
DV: ______
11. The greater the amount of soap in a soap and water mixture, the bigger a soap bubble can be blown
IV: ______
DV: ______
12. The temperature of water was measured at different depths of a pond.
The higher the temperature of water, the faster an egg will boil.
IV: ______
DV: ______
13. An investigation was done with an electromagnetic system made from a battery and wire wrapped around a nail. Different sizes of nails were used. The number of paper clips the electromagnet could pick up was measured.
IV: ______
DV: ______
14. Students of different ages were given the same jigsaw puzzle to put together. They were timed to see how long it took to finish the puzzle.
IV: ______
DV: ______
15. Problem: How does the angle of light affect the temperature of a surface?
IV: ______
DV: ______
16. Problem: How does an increase in the Pacific sea otter population affect the abalonepopulation off the coast of California?
IV: ______
DV: ______
17. Problem: How does the amount of smoking affect emphysema rates?
IV: ______
DV: ______
18. Problem: How does air pressure affect the boiling point of water?
IV: ______
DV: ______
19. The number of puppies in a litter is determined by the size of the mother.
IV: ______
DV: ______
20. A group of students chose to investigate the relationship between the amount oftree movement and wind strength. They used rulers to measure the distance thattree branches moved, and a wind gauge to measure the wind speed. They concludedthat their data supported their hypothesis, which was “If tree branches have moremovement, then the wind speed will be higher, because the leaves push moremolecules in air around.”
Experimental Design Diagram
Title: The effect of the ______on the ______.
(Independent Variable) (Dependent Variable)
Hypothesis: If the ______
(Independent Variable) (Describe how it will be changed)
thenthe ______will ______.
(Dependent Variable) (Describe the effect)
Independent Variable / Levels of IV / # Trials /Dependent Variablelow / 1.
2.
3.
middle / 1.
2.
3.
high / 1.
2.
3.
Independent Variable (IV):
Dependent Variable (DV):
Control:
Constants (C):
What, if anything, is wrong with this investigation? Explain.
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