Open the App

Subjects

Psychology

5 Dec 2025

108

2 pages

Understanding Variables: Key Concepts for Studies

user profile picture

Paulina ๐ŸŒป @chronic..pessimist_3o9u

Planning proper research is crucial for getting reliable results in psychology studies. Understanding different types of variables and... Show more

-planning research

variables

independent variable IV)
variable that is changed/manipulated to see its effect on
the DV

how to operational

Planning Research Variables

Every psychology experiment revolves around variables - the things you change, measure, and try to control. Getting these right from the start determines whether your research will actually prove anything useful.

The independent variable (IV) is what you deliberately change or manipulate to see what happens. Think of it as the cause you're testing - like comparing how boys versus girls perform on a memory test. When you operationalise your IV, be crystal clear about your groups or conditions (e.g., "gender male participants vs female participants").

The dependent variable (DV) is what you measure to see if your IV actually made a difference. This is your effect or outcome. Always operationalise your DV by starting with phrases like "score on..." or "number of..." - you need something you can turn into actual numbers for analysis.

Extraneous variables (EVs) are the sneaky factors that could mess up your results. These include environmental stuff (temperature, noise, time of day), participant differences (age, personality), and experimenter effects (tone of voice, instructions). Standardisation means keeping these EVs identical across all conditions so they can't interfere with your results.

Key Point Poor variable control = unreliable results that other researchers can't replicate!

-planning research

variables

independent variable IV)
variable that is changed/manipulated to see its effect on
the DV

how to operational

Co-variables in Correlational Research

Sometimes you're not trying to prove that one thing causes another - you just want to see if two things are related. That's where co-variables come into play, and they work completely differently from IVs and DVs.

In correlational studies, you don't have independent or dependent variables because you're not manipulating anything. Instead, you measure two co-variables to see if there's a relationship between them. Neither variable is being controlled or changed by the researcher.

For example, if you want to investigate whether blood pressure links to anxiety levels, both blood pressure and anxiety are your co-variables. You'd measure both in the same participants and look for patterns, but you can't claim one causes the other.

Remember that correlations show relationships, not cause and effect. Even if high blood pressure always appears with high anxiety, you can't prove that one directly causes the other - there might be other factors involved.

Remember Co-variables = looking for relationships, not proving what causes what!

We thought youโ€™d never ask...

What is the Knowunity AI companion?

Our AI Companion is a student-focused AI tool that offers more than just answers. Built on millions of Knowunity resources, it provides relevant information, personalised study plans, quizzes, and content directly in the chat, adapting to your individual learning journey.

Where can I download the Knowunity app?

You can download the app from Google Play Store and Apple App Store.

Is Knowunity really free of charge?

That's right! Enjoy free access to study content, connect with fellow students, and get instant help โ€“ all at your fingertips.

2

Smart Tools NEW

Transform this note into: โœ“ 50+ Practice Questions โœ“ Interactive Flashcards โœ“ Full Mock Exam โœ“ Essay Outlines

Mock Exam
Quiz
Flashcards
Essay

Most popular content in Psychology

Most popular content

English - inspector calls quotes and analysis

Quotes from every main character

English LiteratureEnglish Literature
10

Can't find what you're looking for? Explore other subjects.

Students love us โ€” and so will you.

4.9/5

App Store

4.8/5

Google Play

The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.

Stefan S

iOS user

This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.

Samantha Klich

Android user

Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.

Anna

iOS user

Best app on earth! no words because itโ€™s too good

Thomas R

iOS user

Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.

Basil

Android user

This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.

David K

iOS user

The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!

Sudenaz Ocak

Android user

In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.

Greenlight Bonnie

Android user

very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.

Rohan U

Android user

I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didnโ€™t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as Iโ€™m sure you too will see developments.

Xander S

iOS user

THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH ๐Ÿ˜๐Ÿ˜๐Ÿ˜ฒ๐Ÿค‘๐Ÿ’—โœจ๐ŸŽ€๐Ÿ˜ฎ

Elisha

iOS user

This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now

Paul T

iOS user

The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.

Stefan S

iOS user

This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.

Samantha Klich

Android user

Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.

Anna

iOS user

Best app on earth! no words because itโ€™s too good

Thomas R

iOS user

Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.

Basil

Android user

This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.

David K

iOS user

The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!

Sudenaz Ocak

Android user

In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.

Greenlight Bonnie

Android user

very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.

Rohan U

Android user

I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didnโ€™t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as Iโ€™m sure you too will see developments.

Xander S

iOS user

THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH ๐Ÿ˜๐Ÿ˜๐Ÿ˜ฒ๐Ÿค‘๐Ÿ’—โœจ๐ŸŽ€๐Ÿ˜ฎ

Elisha

iOS user

This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now

Paul T

iOS user

ย 

Psychology

โ€ข

108

โ€ข

5 Dec 2025

โ€ข

2 pages

Understanding Variables: Key Concepts for Studies

user profile picture

Paulina ๐ŸŒป

@chronic..pessimist_3o9u

Planning proper research is crucial for getting reliable results in psychology studies. Understanding different types of variables and how to control them makes the difference between good science and dodgy conclusions that nobody can trust.

-planning research

variables

independent variable IV)
variable that is changed/manipulated to see its effect on
the DV

how to operational

Sign up to see the contentIt's free!

Access to all documents

Improve your grades

Join milions of students

By signing up you accept Terms of Service and Privacy Policy

Planning Research Variables

Every psychology experiment revolves around variables - the things you change, measure, and try to control. Getting these right from the start determines whether your research will actually prove anything useful.

The independent variable (IV) is what you deliberately change or manipulate to see what happens. Think of it as the cause you're testing - like comparing how boys versus girls perform on a memory test. When you operationalise your IV, be crystal clear about your groups or conditions (e.g., "gender: male participants vs female participants").

The dependent variable (DV) is what you measure to see if your IV actually made a difference. This is your effect or outcome. Always operationalise your DV by starting with phrases like "score on..." or "number of..." - you need something you can turn into actual numbers for analysis.

Extraneous variables (EVs) are the sneaky factors that could mess up your results. These include environmental stuff (temperature, noise, time of day), participant differences (age, personality), and experimenter effects (tone of voice, instructions). Standardisation means keeping these EVs identical across all conditions so they can't interfere with your results.

Key Point: Poor variable control = unreliable results that other researchers can't replicate!

-planning research

variables

independent variable IV)
variable that is changed/manipulated to see its effect on
the DV

how to operational

Sign up to see the contentIt's free!

Access to all documents

Improve your grades

Join milions of students

By signing up you accept Terms of Service and Privacy Policy

Co-variables in Correlational Research

Sometimes you're not trying to prove that one thing causes another - you just want to see if two things are related. That's where co-variables come into play, and they work completely differently from IVs and DVs.

In correlational studies, you don't have independent or dependent variables because you're not manipulating anything. Instead, you measure two co-variables to see if there's a relationship between them. Neither variable is being controlled or changed by the researcher.

For example, if you want to investigate whether blood pressure links to anxiety levels, both blood pressure and anxiety are your co-variables. You'd measure both in the same participants and look for patterns, but you can't claim one causes the other.

Remember that correlations show relationships, not cause and effect. Even if high blood pressure always appears with high anxiety, you can't prove that one directly causes the other - there might be other factors involved.

Remember: Co-variables = looking for relationships, not proving what causes what!

We thought youโ€™d never ask...

What is the Knowunity AI companion?

Our AI Companion is a student-focused AI tool that offers more than just answers. Built on millions of Knowunity resources, it provides relevant information, personalised study plans, quizzes, and content directly in the chat, adapting to your individual learning journey.

Where can I download the Knowunity app?

You can download the app from Google Play Store and Apple App Store.

Is Knowunity really free of charge?

That's right! Enjoy free access to study content, connect with fellow students, and get instant help โ€“ all at your fingertips.

2

Smart Tools NEW

Transform this note into: โœ“ 50+ Practice Questions โœ“ Interactive Flashcards โœ“ Full Mock Exam โœ“ Essay Outlines

Mock Exam
Quiz
Flashcards
Essay

Most popular content in Psychology

Most popular content

English - inspector calls quotes and analysis

Quotes from every main character

English LiteratureEnglish Literature
10

Can't find what you're looking for? Explore other subjects.

Students love us โ€” and so will you.

4.9/5

App Store

4.8/5

Google Play

The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.

Stefan S

iOS user

This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.

Samantha Klich

Android user

Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.

Anna

iOS user

Best app on earth! no words because itโ€™s too good

Thomas R

iOS user

Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.

Basil

Android user

This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.

David K

iOS user

The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!

Sudenaz Ocak

Android user

In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.

Greenlight Bonnie

Android user

very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.

Rohan U

Android user

I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didnโ€™t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as Iโ€™m sure you too will see developments.

Xander S

iOS user

THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH ๐Ÿ˜๐Ÿ˜๐Ÿ˜ฒ๐Ÿค‘๐Ÿ’—โœจ๐ŸŽ€๐Ÿ˜ฎ

Elisha

iOS user

This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now

Paul T

iOS user

The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.

Stefan S

iOS user

This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.

Samantha Klich

Android user

Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.

Anna

iOS user

Best app on earth! no words because itโ€™s too good

Thomas R

iOS user

Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.

Basil

Android user

This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.

David K

iOS user

The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!

Sudenaz Ocak

Android user

In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.

Greenlight Bonnie

Android user

very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.

Rohan U

Android user

I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didnโ€™t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as Iโ€™m sure you too will see developments.

Xander S

iOS user

THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH ๐Ÿ˜๐Ÿ˜๐Ÿ˜ฒ๐Ÿค‘๐Ÿ’—โœจ๐ŸŽ€๐Ÿ˜ฎ

Elisha

iOS user

This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now

Paul T

iOS user