Practice English Speaking&Listening with: Compare Groups of Scores with SPSS for Beginners

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Welcome to this tutorial on using spss to make sense of data. The example is about the impact of violent

programs on TV and display of aggressive behavior.

The example for this tutorial is on page 14 of the textbook "Essential of

statistics for behavioral sciences" and the textbook is by Gravetter

and Wallnau. Research question: "Is there a relationship between the amount of

violence the children see on television and the amount of aggressive behavior?"

(In this example) 18 kids are selected randomly from the population?

This is an (example of) experimental data ... experimental research design in which

one variable is whether the children watch or don't watch TV programs with violence

the variable one is "Violence" and

this variable has two values (1 and 2): the number one means that they watch TV programs with

violence, and number two

means that the children don't watch such programs. The secont variable, variable two is display of aggressive

behavior. The second variable is measures the number of aggressive instances. The values of this variable vary from zero to

four.

We will use the textbook data and spss. The goal is to enter data into SPSS then

we will let spss to organize and visualize the data for us. You know this

can happen with the click of a mouse or few clicks of our mouse. Then we will

make sense of this data.

In SPSS, first we will go in Variable View, and will enter our two variables. The first variable is

Violence on TV. The name of the variable is "Violence." The

label is "Violence on TV." As you know we use label for the variable, because the name name of the variable in SPSS should be only one word. This is

a string type of variable with two values. I will give values to numerical symbols:

1 means that the children are watching violent movies or

programs' and 2 means the children in the second group do not watch violent programs.

The first variable is ready. This variable this is controlled by the research

scientists. Researchers are controlling that children from the first group are watching violent programs, and

children from the second group are not watching violent programs. Researchers should not allow anything else to

interfere with this variable, which is the only one independent variable.

The second variable is "Aggression."

This is a numerical variable. The aggressive behavior ...

The variable is measured as a scale iin SPSS (interval/ratio level of measurement).

The two variables are identified in "Variable View."

In "Data View," I can use "1" for Violence, and I can copy the repetitive values.

On the key board, "Control C" will copy, and "Control + V" will paste the selected group of values.

Now let's enter the data for the second variable, Aggression. We have four values.

4, 2, 0, ...

Now i will form two groups. I will select all scores from the first group and will copy

and paste the scores in a new column, somewhere in here.

this is the group of children exposed to violent programs on TV. And then I willl copy the No Violence" group.

SPSS automatically forms two column, called "Variable 12" and "Variable 13."

Let's switch to "Variable View" and change "Variable 12" to aggression with violence

and "Variable 13" would be aggression with no violence.

so I split one variable in two groups.

In this case, the Violence on TV is a controlled or independent variable.

I will visualize the first group by Histogram - how many children have zero instances of violence, one instance, etc.

So, you can see that there are many children in this group who actually display more violent behavior (skew to the right),

which means a lot of aggression. Then, I will do graph the second group as a histogram. Let's see

the frequency distribution if kids don't watch violent programs.

So the children who are not exposed to violent programs on TV have much less

violent behavior.

i will copy these hystograms. Control C copy and will place it in PowerPoint (Control V). Immediately you can see

that very few children from who do not watch violent programs have high level of aggressive behavior. (left graph).

We can see there is difference between the two histograms.

Children who do not watch violent programs on TV do not display violent behavior.

Children who watch violent programs, display more instances of violent behavior.

The Description of Compare Groups of Scores with SPSS for Beginners