I was wondering if anybody could help me with my science assignment.I was required to write out a method for a controlled experiment testing my hypothesis: "Physical activity affects heart rate" and I've no idea what my method is to test out this experiment.
Please help &thankyou~
A review of the experimental method might be helpful.
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 is controlled by third party. This controls for experimenter bias and self-fulfilling prophecy. This 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.
I need any 7th grade experiment that is easy bot not too hard
Of course, I can help you with your science assignment. To test your hypothesis that physical activity affects heart rate, you would need to design a controlled experiment. Here is a step-by-step method you can use:
1. Identify your variables: In your experiment, the independent variable is physical activity, and the dependent variable is the heart rate.
2. Define your control group: Have a group of participants who will not engage in any physical activity. This will serve as your control group to compare the heart rate changes.
3. Define your experimental group: Have another group of participants who will engage in physical activity. This group will allow you to observe the changes in heart rate compared to the control group.
4. Randomize and select participants: Randomly assign participants to either the control group or the experimental group. Make sure the groups are similar in terms of age, gender, health status, etc.
5. Take baseline measurements: Measure the participants' resting heart rate before any physical activity. Ensure that all participants are in a calm and relaxed state during this measurement.
6. Perform physical activity: Instruct participants in the experimental group to engage in a specific physical activity. This could involve running, jumping, cycling, or any other exercise that elevates heart rate.
7. Monitor heart rate: Use heart rate monitors or manual pulse measurements to record the heart rate of participants immediately after the physical activity.
8. Repeat measurements: Wait for a specified amount of time (e.g., 5 minutes) and take heart rate measurements again for both groups. Multiple measurements will help ensure reliable data.
9. Analyze the data: Compare the average heart rate of the control group with the average heart rate of the experimental group at each time point. Determine if there are any significant differences.
10. Draw conclusions: Based on the data analysis, determine if physical activity indeed affects heart rate. Consider any limitations or potential sources of error in your experiment.
Remember to document every step of your method, including details about participants, equipment used, and any other relevant information. This will ensure that your experiment can be replicated by others and provide accurate results.