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August 25, 2019, 12:16:22 am

Author Topic: Purpose of control and experimental group?  (Read 493 times)  Share 

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almostdonewithschooling

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Purpose of control and experimental group?
« on: February 12, 2018, 06:27:00 pm »
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Is the purpose for control group is to determine whether or not if there was any effect from the treatment of experiment group?

and what's the purpose of control group?


Another question: how do we determine a likely sample??

Ex. People who fear cats will also fear dogs?

lazaward

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Re: Purpose of control and experimental group?
« Reply #1 on: February 12, 2018, 06:48:54 pm »
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The purpose of a control group is to act as a comparison to the experimental group to see the effect of the treatment (independent variable), so yes you are right. As for your second question I'm not quite sure what you mean by it, do you mean how to determine a sample???

Poet

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Re: Purpose of control and experimental group?
« Reply #2 on: February 12, 2018, 07:11:58 pm »
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Yes, almostdonewithschooling, the control group is there to provide a basis off which the experiment can claim validity. Without a control group, how are we meant to measure the effects on a variable?
To be put more simply, if a person who fears cats has a reaction, you need to be able to compare their behaviour with that of a person who does not fear cats. Hence the control and experimental groups are born!

To answer your next question, determining a likely sample is just a question of logic. Think about the likely outcome and decide whether you can set up a proper experiment that prevents extraneous variables. If you're thinking about cats and dogs, it actually depends on a lot of things in a person's background and their personal experiences with dogs, cats, and animals in general. It would be difficult to get a clear answer, so you would have to do a specific sample due to people's experience, which is not a fair sample.

I hope you can understand, psych can get a little weird! :)
« Last Edit: February 12, 2018, 07:17:36 pm by secretly_a_poet »
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almostdonewithschooling

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Re: Purpose of control and experimental group?
« Reply #3 on: February 12, 2018, 07:22:37 pm »
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Ahh thanks guys. I was meant to ask, what's the purpose of the experimental group not control

Poet

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Re: Purpose of control and experimental group?
« Reply #4 on: February 12, 2018, 07:47:38 pm »
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Ahh thanks guys. I was meant to ask, what's the purpose of the experimental group not control

OH LOL! I hope my explanation covered the purpose of both?
You're both the fire and the water that extinguishes it.
You're the narrator, the protagonist, and the sidekick.
You're the storyteller and the story told.
You are somebody's something, but you are also your you.

Dealing with Year 12 - Put Your Mental Health at the Forefront
A Little Guide to Healthy Eating

almostdonewithschooling

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Re: Purpose of control and experimental group?
« Reply #5 on: February 12, 2018, 08:02:47 pm »
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The answer for the dog and cats says  a substantial number (100+) with a fear of cats

Poet

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Re: Purpose of control and experimental group?
« Reply #6 on: February 12, 2018, 08:07:38 pm »
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That is logical, if the aim of the experiment was to see whether or not people who feared cats also fear dogs, wasn't it?  :P
You're both the fire and the water that extinguishes it.
You're the narrator, the protagonist, and the sidekick.
You're the storyteller and the story told.
You are somebody's something, but you are also your you.

Dealing with Year 12 - Put Your Mental Health at the Forefront
A Little Guide to Healthy Eating

Bri MT

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Re: Purpose of control and experimental group?
« Reply #7 on: February 16, 2018, 04:04:26 pm »
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Ahh thanks guys. I was meant to ask, what's the purpose of the experimental group not control

There have been some good answers here already but for further clarification:

The purpose of an experiment is to investigate the relationship between variables.

So if you wanted to test if exposure to sunlight (independent variable) increases the height of gum trees you would test how high gum trees grow when 1. Gum trees are exposed to light and when 2.  Gum trees are not exposed to light.
If you only had gum trees in situation one or only in situation 2 the results would be meaningless as you would have no idea what the impact of the situation was (as there is nothing to compare it to).
However, if you have gum trees in both situations you can compare them and this draw conclusions about the effect of sunlight. 

The way that I have phrased it 1. is the experimental group and 2. Is the control group. However,  I could  have asked if "non-exposure to sunlight decreases gum tree height" in which case 1. would be the control and 2. would be the experimental group.

Hopefully this demonstrates to you that the experimental and control group both have the same role: to act as a comparison against the other.  Neither has meaning without the other.
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