Bart believes that mice exposed to microwaves will become extra strong (maybe he's been reading too much Radioactive Man). He decides to perform this experiment by placing 10 mice in a microwave for 10 seconds. He compared these 10 mice to another 10 mice that had not been exposed. His test consisted of a heavy block of wood that blocked the mouse food. he found that 8 out of 10 of the microwaved mice were able to push the block away. 7 out of 10 of the non-microwaved mice were able to do the same.
Identify the-
11. Control Group
12. Independent Variable
13. Dependent Variable
14. What should Bart's conclusion be?
15. How could Bart's experiment be improved?
Control group- non microwaved mice
Independent Variable- exposure to the microwave
Dependent Variable- the weight of the block of wood
Conclusion- Microwaved mice will be extra strong.
Improvement- Repeat the experiment a few more times and compare the results.
Owls hunt mice. An owl hears a mouse. How will the owl react?
A.
The owl will fly away.
B.
The owl will swoop down to catch the mouse.
C.
The owl will stare at the mouse.
D.
The owl will scream to alert other owls.
B duh
11. The control group in Bart's experiment is the group of mice that were not exposed to microwaves.
12. The independent variable in Bart's experiment is the exposure to microwaves.
13. The dependent variable in Bart's experiment is the ability of the mice to push the block of wood away.
14. Bart's conclusion should be that exposure to microwaves does not necessarily result in extra strength for mice. This is because a higher percentage of the non-microwaved mice were able to push the block away compared to the microwaved mice.
15. Bart's experiment could be improved in several ways.
a) Increase the sample size: The experiment should be conducted with a larger number of mice to increase statistical significance and reduce the impact of random variation.
b) Randomize the groups: Assign the mice randomly to the microwave group and control group to minimize bias and ensure equal representation of characteristics that could affect the results.
c) Use a longer exposure time: 10 seconds might not be a sufficient duration for any potential effects to manifest. Testing with longer exposure times could provide more reliable results.
d) Include multiple trials: Conduct several repetitions of the experiment to account for any variations or inconsistencies within the mice population.
e) Consider alternative measures: Instead of just using the ability to push the block of wood as the only measure, additional parameters like strength measurement, agility, or other physical tests could be included to provide a more comprehensive understanding of the mice's abilities.
f) Seek expert guidance: Bart could consult experts or relevant scientific literature to gain guidance on experimental design, variables, and interpretation of results.
It might help to review the above concepts.
An independent variable is the potential stimulus or cause, usually directly manipulated by the experimenter, so it could also be called a manipulative variable.
A dependent variable is the response or measure of results.
Extraneous variables — other than the independent variable — potentially can affect the dependent variable, so they must be controlled. If possible, you try to keep them constant between the experimental and control group.
The experimental group receives the independent variable.
The control group is similar to experimental, except it does not receive the independent variable. Extraneous variables are balanced between experimental and control groups.
Types of experiments
1. Single blind gives the control group a placebo — a substance that is inert, it has no physical effect. Subjects don't know if they are in experimental or control group to reduce placebo effect, a change in behavior solely due to believing that you are getting the independent variable.
2. Double blind keeps both subjects and experimenter ignorant of group setup. Distribution of the independent variable and placebo are controlled by third party. This controls for experimenter bias and self-fulfilling prophecy, which means that experimenters with particular expectations are likely to consciously or unconsciously to bias the experiment and influence it to conform to their expectations.
As an example, suppose you want to find out if fluorides reduce dental cavities. You would find two groups, trying to control the extraneous variables. Extraneous variables are found by surveying previous research in the area. In this case, you would match the groups in terms of previous history of cavities, diet and dental hygiene habits including how and how often they brush their teeth.
The experimental group would get toothpaste with the independent variable, the fluoride, while the control group would not have the fluoride in their toothpaste. The toothpaste without the fluoride would be the placebo.
The dependent variable would be the number of cavities after participating in the experiment for a time. The dependent variable indicates the results, but it is not the results. At the end of the experiment, both groups could have no change in cavities or one of the groups could have a greater reduction in cavities. (Of course, if the fluoride increased cavities, you wouldn't want to use it.) All of these varied results would be indicated in terms of the dependent variable.
If only the subjects do not know who is getting the fluoride, it is a single blind experiment. If both the subjects and experimenter do not know, it is a double blind.
I hope this helps a little more. Thanks for asking.