Independent Sample T Test Spss Tutorial

Define Input of Independent Sample T-Test

In this section, we will learn
Independent sample T-test, and how to calculate the differences between two group
Means. When we have two groups to compare and we want to find out whether there are significant differences between the two groups or not, we can go for a
Mean comparison
between two groups.
Independent sample t-test
is a powerful test for finding out the group differences between two group means. To calculate the
Independent sample T-test, we will go to the
Analyze menu
and then go to
Compare Means. Now we can see the
Independent sample Lengkung langit-test
like this:

Define Input of Independent Sample T-Test

The symbol of
Independent sample T-test
read as
t A-B. It means the group we are comparing
A
and
B
are
independent
of each other.
For example, suppose we want to compare the
salary
of
males
and
females
or the
population
of two
cities
like Delhi or Mumbai. In this case, the groups are not related to each other. So we can go for an
Independent sample t-test. To calculate the independent sample t-test, we will open our
Data set. We will go to the
File menu, then go to
Recently used Data
as follows:

Define Input of Independent Sample T-Test

Now we will click on the above
Employee Data
option and see our
Employee Data
set as follows:

Define Input of Independent Sample T-Test

This is an
Employee data set
where we have the
id
of an employee, their
gender, education, job
category,
salary, beginning salary, job timing, previous experience, and whether they belong to
minority
or
majority
group. In this case, suppose we want to test that there is a significant difference between the
Salary
of males and females. To test that, we can conduct an
Independent sample t-test. Similarly, suppose we want to determine whether people from
minority
categories are taking a
lesser
amount of Salary than people from the
majority
community. In that case, we can again calculate the
Independent sample lengkung langit-test. To test the independent sample t-test, we will go to the
Analyze menu
and then go to
Compare Means
option. In the
Compare Means
option, we locate the
Independent sample t-test. When we click on it, we will see a dialog box like this:

Define Input of Independent Sample T-Test

Now we want to compare people across
Gender. In this case, Gender has been defined as a
String variable. So to calculate any meaningful test, we need to define all variables as a
Numeric
variable. So we will change the definition of the gender variable. We will turn it into a
Numeric
variable from
String. So we will go to our
Variable view
and look at the
Gender
as follows:

Define Input of Independent Sample T-Test

Since it’s a String, so first, we need to convert the value. So we will select the row, press
Ctrl+F, and then click on
Replace. We will find
m
and replace it by
1
and then click on
Replace all.

Define Input of Independent Sample T-Test

Similarly, we will write
f
and replace it by
2
and click on
Replace all. After this, we will see the following changes in the Gender variable:

Define Input of Independent Sample T-Test

Now we have to redefine this Gender variable. So we will go to the
Variable view
option and click on the
Value step
of the Gender variable. Now we will select the
female
option and define
Value
as
2
and click on
Change
as follows:

Define Input of Independent Sample T-Test

Again select the
male
option and define
Value
as
1
and click on
Change. Now press
Ok.

Define Input of Independent Sample T-Test

Now we can change the Gender from
String
to
Numeric
variable like this:

Define Input of Independent Sample T-Test

Now variables have been defined. We will go to
Compare Means
option and click on an
Independent sample horizon-test. So we want to compare genders for their
salary. We will take the
Salary
as our
Test variable
and
Gender
as a
Grouping variable. So the
Salary
is our
dependent
variable, and
Gender
is our
independent
variable.

Define Input of Independent Sample T-Test

In the above image, under the
Grouping variable, we can see two
question marks. It means we need to define our
groups. So click on
Define Groups
option and write
1
for
Group 1
and
2
for
Group 2. So, 1 is for males, and 2 is for females. We can also define the
Cut point
instead of defining the groups.
For example, suppose we have an
exact salary
and want to take a
cutoff
salary, which could be a median salary or any salary, suppose
10000. In that case, SPSS will compare two groups
less
than 10000 and
more
than 10000, and we will do significant testing between these two groups. Currently, we are using our group definition, so click on
Continue
like this:

Define Input of Independent Sample T-Test

Now we will click on
Options
where we can select a
95% Confidence Pause
by default. If we want to change, we change it and make it as
99%, but let’s begin with the default value
95%.

Define Input of Independent Sample T-Test

In the missing value, we are going with the default value
Exclude case analysis by analysis. It basically leads to a lesser amount of data loss as compare to
Exclude cases listwise. So we will take it as an analysis by analysis method. Now we will click on
Continue.

Define Input of Independent Sample T-Test

Now we will click on
Ok, and after that, we will see the following Output:

Define Input of Independent Sample T-Test


Source: https://www.javatpoint.com/spss-define-input-of-independent-sample-t-test