How many variables are there?

This presentation is designed to help you identify the number of variables in your relationship-oriented question.

Here are your options:

Here are your options:

2 variables

3 or more varaiables

or

What is a variable?

A variable is something that can vary or change.

First a variable is something that can vary or change.

For example, temperature varies from day to day.

First a variable is something that can vary or changes.

For example, temperature varies from day to day.

Ice cream sales can vary from day to day.

First a variable is something that can vary or changes.

For example, temperature varies from day to day.

Ice cream sales can vary from day to day.

Religious affiliation (eg., Catholic, Protestant, Jew, Mormon, Muslim) can vary from person to person.

First a variable is something that can vary or changes.

For example, temperature varies from day to day.

Ice cream sales can vary from day to day.

Religious affiliation (eg., Catholic, Protestant, Jew, Mormon, Muslim) can vary from person to person.

While gender can only vary two ways (e.g. male, female), it sill varies from person to person and therefore is a variable.

First a variable is something that can vary or changes.

For example, temperature varies from day to day.

Ice cream sales can vary from day to day.

Religious affiliation (eg., Catholic, Protestant, Jew, Mormon, Muslim) can vary from person to person.

While gender can only vary two ways (e.g. male, female), it sill varies from person to person and therefore is a variable.

In a relationship question there are generally two variables whose relationship is under investigation.

For example:

Researchers wish to determine the relationship between vitamin B intake and soccer player cramping.

Researchers wish to determine the relationship between vitamin B intake and soccer player cramping.

One variable

Researchers wish to determine the relationship between vitamin B intake and soccer player cramping.

This variable could take on a whole range

of values

Researchers wish to determine the relationship between vitamin B intake and soccer player cramping.

such as

Researchers wish to determine the relationship between vitamin B intake and soccer player cramping.

such as 1-10 grams

Researchers wish to determine the relationship between vitamin B intake and soccer player cramping.

such as 1-10 grams

Soccer Player

VitaminB Grams

A 9

B 1

C 3

D 2

E 10

Or the variable can take on another set of values.

1 = No vitamin B2 = Some vitamin B3 = A lot of vitamin B

1 = No vitamin B2 = Some vitamin B3 = A lot of vitamin B

Soccer Player

Amount of Vit B

A

B

C

D

E

1 = No vitamin B2 = Some vitamin B3 = A lot of vitamin B

Soccer Player

Amount of Vit B

A 3

B 1

C 2

D 3

E 2

Researchers wish to determine the relationship between vitamin B intake and soccer player cramping.

This 2nd variable could take on a whole range of values as well.

Researchers wish to determine the relationship between vitamin B intake and soccer player cramping.

such as

Researchers wish to determine the relationship between vitamin B intake and soccer player cramping.

such as0 cramps per game1 cramps per game2 cramps per game3 cramps per game, etc.

Researchers wish to determine the relationship between vitamin B intake and soccer player cramping.

such as0 cramps per game1 cramps per game2 cramps per game3 cramps per game, etc.

Soccer Player

Amount of Vit B

A 3

B 1

C 2

D 3

E 2

Researchers wish to determine the relationship between vitamin B intake and soccer player cramping.

such as0 cramps per game1 cramps per game2 cramps per game3 cramps per game, etc.

Soccer Player

Amount of Vit B

Cramps Per Game

A 3 0

B 1 4

C 2 2

D 3 1

E 2 2

Therefore:

This was an example of a word problem with two variables:

This was an example of a word problem with two variables:

Researchers wish to determine the relationship between vitamin B intake and soccer player cramping.

This was an example of a word problem with two variables:

Researchers wish to determine the relationship between vitamin B intake and soccer player cramping.

Soccer Player

Amount of Vit B

Cramps Per Game

A 3 0

B 1 4

C 2 2

D 3 1

E 2 2

This was an example of a word problem with two variables:

Researchers wish to determine the relationship between vitamin B intake and soccer player cramping.

Soccer Player

Amount of Vit B

Cramps Per Game

A 3 0

B 1 4

C 2 2

D 3 1

E 2 2

1st variable

This was an example of a word problem with two variables:

Researchers wish to determine the relationship between vitamin B intake and soccer player cramping.

Soccer Player

Amount of Vit B

Cramps Per Game

A 3 0

B 1 4

C 2 2

D 3 1

E 2 2

2nd variable

Here is another example:

You have been asked to see if third graders tend to bully fellow class mates more than fourth graders across 5 different schools.

You have been asked to see if third graders tend to bully fellow class mates more than fourth gradersacross 5 different schools.

You have been asked to see if third graders tend to bully fellow class mates more than fourth gradersacross 5 different schools.

1st variable –Grade Level

1 = 3rd graders2 = 4th graders

You have been asked to see if third graders tend to bully fellow class mates more than fourth graders across 5 different schools.

1st variable –Grade Level

1 = 3rd graders2 = 4th graders

You have been asked to see if third graders tend to bully fellow class mates more than fourth graders across 5 different schools.

You have been asked to see if third graders tend to bully fellow class mates more than fourth graders across 5 different schools.

2nd variable –bullying

Incidents of Bullying per

week (1, 2, 3, 4, etc.)

You have been asked to see if third graders tend to bully fellow class mates more than fourth graders across 5 different schools.

2nd variable –bullying

Incidents of bullying per

week (1, 2, 3, 4, etc.)

Here is what the data set might look like:

You have been asked to see if third graders tend to bully fellow class mates more than fourth graders across 5 different schools.

You have been asked to see if third graders tend to bully fellow class mates more than fourth graders across 5 different schools.

You have been asked to see if third graders tend to bully fellow class mates more than fourth graders across 5 different schools.

School Grade 1 = 3rd

2 = 4th

Incidents of

Bullying

A

B

C

D

E

You have been asked to see if third graders tend to bully fellow class mates more than fourth graders across 5 different schools.

School Grade 1 = 3rd

2 = 4th

Incidents of

Bullying

A 1

B 2

C 1

D 1

E 2

You have been asked to see if third graders tend to bully fellow class mates more than fourth graders across 5 different schools.

School Grade 1 = 3rd

2 = 4th

Incidents of

Bullying

A 1

B 2

C 1

D 1

E 2

You have been asked to see if third graders tend to bully fellow class mates more than fourth graders across 5 different schools.

School Grade 1 = 3rd

2 = 4th

Incidents of

Bullying

A 1 5

B 2 2

C 1 6

D 1 7

E 2 1

You have been asked to see if third graders tend to bully fellow class mates more than fourth graders across 5 different schools.

School Grade 1 = 3rd

2 = 4th

Incidents of

Bullying

A 1 5

B 2 2

C 1 6

D 1 7

E 2 1

Once again, there are two variables in this problem

There are other instances when you have three or more variables:

For example:

University administrators wish to know the degree to which GPA, ACT scores, and the number of extracurricular activities applicants participated in, predict students being admitted into the university.

University administrators wish to know the degree to which GPA, ACT scores, and the number of extracurricular activities applicants participated in, predict students being admitted into the university.

Applicant GPA ACT # of ExtracrclrActivities

Admitted 1 = yes, 2 = no

A

B

C

D

E

University administrators wish to know the degree to which GPA, ACT scores, and the number of extracurricular activities applicants participated in, predict students being admitted into the university.

Applicant GPA ACT # of ExtracrclrActivities

Admitted 1 = yes, 2 = no

A

B

C

D

E

University administrators wish to know the degree to which GPA, ACT scores, and the number of extracurricular activities applicants participated in, predict students being admitted into the university.

Applicant GPA ACT # of ExtracrclrActivities

Admitted 1 = yes, 2 = no

A

B

C

D

E

University administrators wish to know the degree to which GPA, ACT scores, and the number of extracurricular activities applicants participated in, predict students being admitted into the university.

Applicant GPA ACT # of ExtracrclrActivities

Admitted 1 = yes, 2 = no

A 3.2

B 3.7

C 3.1

D 2.8

E 3.9

University administrators wish to know the degree to which GPA, ACT scores, and the number of extracurricular activities applicants participated in, predict students being admitted into the university.

Applicant GPA ACT # of ExtracrclrActivities

Admitted 1 = yes, 2 = no

A 3.2

B 3.7

C 3.1

D 2.8

E 3.9

1st Variable

University administrators wish to know the degree to which GPA, ACT scores, and the number of extracurricular activities applicants participated in, predict students being admitted into the university.

Applicant GPA ACT # of ExtracrclrActivities

Admitted 1 = yes, 2 = no

A 3.2

B 3.7

C 3.1

D 2.8

E 3.9

University administrators wish to know the degree to which GPA, ACT scores, and the number of extracurricular activities applicants participated in, predict students being admitted into the university.

Applicant GPA ACT # of ExtracrclrActivities

Admitted 1 = yes, 2 = no

A 3.2 26

B 3.7 27

C 3.1 22

D 2.8 25

E 3.9 23

University administrators wish to know the degree to which GPA, ACT scores, and the number of extracurricular activities applicants participated in, predict students being admitted into the university.

Applicant GPA ACT # of ExtracrclrActivities

Admitted 1 = yes, 2 = no

A 3.2 26

B 3.7 27

C 3.1 22

D 2.8 25

E 3.9 23

2nd Variable

University administrators wish to know the degree to which GPA, ACT scores, and the number of extracurricular activities applicants participated in, predict students being admitted into the university.

Applicant GPA ACT # of ExtracrclrActivities

A 3.2 26 5

B 3.7 27 3

C 3.1 22 0

D 2.8 25 1

E 3.9 23 3

University administrators wish to know the degree to which GPA, ACT scores, and the number of extracurricular activities applicants participated in, predict students being admitted into the university.

Applicant GPA ACT # of ExtracrclrActivities

Admitted 1 = yes, 2 = no

A 3.2 26 5

B 3.7 27 3

C 3.1 22 0

D 2.8 25 1

E 3.9 23 3

University administrators wish to know the degree to which GPA, ACT scores, and the number of extracurricular activities applicants participated in, predict students being admitted into the university.

Applicant GPA ACT # of ExtracrclrActivities

Admitted 1 = yes, 2 = no

A 3.2 26 5

B 3.7 27 3

C 3.1 22 0

D 2.8 25 1

E 3.9 23 3

3rd Variable

University administrators wish to know the degree to which GPA, ACT scores, and the number of extracurricular activities applicants participated in, predict students being admitted into the university.

Applicant GPA ACT # of ExtracrclrActivities

A 3.2 26 5

B 3.7 27 3

C 3.1 22 0

D 2.8 25 1

E 3.9 23 3

University administrators wish to know the degree to which GPA, ACT scores, and the number of extracurricular activities applicants participated in, predict students being admitted into the university.

Applicant GPA ACT # of ExtracrclrActivities

Admitted 1 = yes, 2 = no

A 3.2 26 5 1

B 3.7 27 3 1

C 3.1 22 0 2

D 2.8 25 1 2

E 3.9 23 3 1

University administrators wish to know the degree to which GPA, ACT scores, and the number of extracurricular activities applicants participated in, predict students being admitted into the university.

Applicant GPA ACT # of ExtracrclrActivities

Admitted 1 = yes, 2 = no

A 3.2 26 5 1

B 3.7 27 3 1

C 3.1 22 0 2

D 2.8 25 1 2

E 3.9 23 3 1

4th Variable

So, that is an example of a word problem with three or more variables.

Note – there is one special case that you should be aware of.

Some word problems will be worded as follows:

You have been asked to determine if a relationship exists between the amount of peanut butter consumed and gender controlling for age.

You have been asked to determine if a relationship exists between the amount of peanut butter consumed and gender controlling for age.

Here is the data set for this question

You have been asked to determine if a relationship exists between the amount of peanut butter consumed and gender controlling for age.

StudyParticipant

Average Daily Peanut Butter

Intake in grams

Gender1 = male

2 = female

Age1 = 0-25

2 = 26-45

A 6 1 1

B 3 1 2

C 2 2 1

D 4 2 2

E 2 1 1

You have been asked to determine if a relationship exists between the amount of peanut butter consumed and gender controlling for age.

StudyParticipant

Average Daily Peanut Butter

Intake in grams

Gender1 = male

2 = female

Age1 = 0-25

2 = 26-45

A 6 1 1

B 3 1 2

C 2 2 1

D 4 2 2

E 2 1 1

1st Variable

You have been asked to determine if a relationship exists between the amount of peanut butter consumed and gender controlling for age.

StudyParticipant

Average Daily Peanut Butter

Intake in grams

Gender1 = male

2 = female

Age1 = 0-25

2 = 26-45

A 6 1 1

B 3 1 2

C 2 2 1

D 4 2 2

E 2 1 1

You have been asked to determine if a relationship exists between the amount of peanut butter consumed and gender controlling for age.

StudyParticipant

Average Daily Peanut Butter

Intake in grams

Gender1 = male

2 = female

Age1 = 0-25

2 = 26-45

A 6 1 1

B 3 1 2

C 2 2 1

D 4 2 2

E 2 1 1

2nd Variable

You have been asked to determine if a relationship exists between the amount of peanut butter consumed and gender controlling for age.

StudyParticipant

Average Daily Peanut Butter

Intake in grams

Gender1 = male

2 = female

Age1 = 0-25

2 = 26-45

A 6 1 1

B 3 1 2

C 2 2 1

D 4 2 2

E 2 1 1

You have been asked to determine if a relationship exists between the amount of peanut butter consumed and gender controlling for age.

StudyParticipant

Average Daily Peanut Butter

Intake in grams

Gender1 = male

2 = female

Age1 = 0-25

2 = 26-45

A 6 1 1

B 3 1 2

C 2 2 1

D 4 2 2

E 2 1 1

Age is actually NOTconsidered a 3rd Variable

You have been asked to determine if a relationship exists between the amount of peanut butter consumed and gender controlling for age.

StudyParticipant

Average Daily Peanut Butter

Intake in grams

Gender1 = male

2 = female

Age1 = 0-25

2 = 26-45

A 6 1 1

B 3 1 2

C 2 2 1

D 4 2 2

E 2 1 1

That is because the two variables of interest are peanut butter intake and gender, controlling for

age is an additional analysis.

You have been asked to determine if a relationship exists between the amount of peanut butter consumed and gender controlling for age.

StudyParticipant

Average Daily Peanut Butter

Intake in grams

Gender1 = male

2 = female

Age1 = 0-25

2 = 26-45

A 6 1 1

B 3 1 2

C 2 2 1

D 4 2 2

E 2 1 1

The idea of controlling for another variable will be explained in another presentation, but it is important for you to know that a problem like this is

examining the relationship between TWO not Three variables.

Look at the problem you are working on and determine if it contains:

Look at the problem you are working on and determine if it contains:

2 variables

3 or more varaiables

or