Lecture-1emrulmahmud.weebly.com/uploads/5/2/4/2/52421679/lecture-1.pdf · Md. Abdullah Al Mahmud Senior Lecturer Manarat International University Data: A data set is the organized

Md. Abdullah Al Mahmud Senior Lecturer

Manarat International University

Lecture-1 Introduction to SPSS

What is SPSS?

The statistical package SPSS was first devised in 1966. Actually SPSS was developed as an

analysis program for social scientists.

SPSS [Statistical Package for Social Sciences] is a program that allows us to describe and

analyze data.

Analysis of data using SPSS

Proficiency with statistical software package is indispensable today for research in Business.

SPSS is one of the most widely used and powerful statistical software packages. It covers a

broad range of statistical procedures that allow us to summarize data (e.g mean, standard

deviation, CV), examine relationships among variables (e.g. correlation, regression), determine

whether there are significant difference between groups (e.g t-test, z-test, ANOVA), and

graphical presentation of results (e.g bar chart, line chart, histogram). It can easily perform

almost any statistical analysis.

What can SPSS do?

manipulate and manage data

produce reports and tables

perform simple and complex statistical analyses

produce graphical output

SPSS for windows: Getting started

You can start SPSS either by clicking on SPSS for windows in the Programs of start button or by

double clicking its shortcut icon.



What do we see first?

Once SPSS has been initialized the first screen which we see in SPSS will look like that in the figure1.1. This first window is the Data Editor. Here we enter data and save it as a data file. To begin with it is called Untitled- SPSS Data Editor. This indicates that this is a new and as yet, empty data file.

Figure 1.1: SPSS initial screen display-The Data Editor

Composition of the Data File

The topmost along the top of the screen we see the Menu Bar is used to access all the commands available. The Menu Bar has a number of headings, splitting the commands into categories of similar functions (File, Edit, View, Data, Transform, Analyze, Graphs, Utilities, Window, and Help).



Data:

A data set is the organized or structured form of information obtained from experiments, surveys

or other sources. Before starting data analysis in SPSS, it is important to be clear about how the

variables are recorded for each case individual.

Note that: In the Data Editor window of SPSS each column will represent a variable and each

row will stand for a case or respondent or individual.

Creating the Data File

Here is the step-by-step procedure for creating data file with the help of the following example.

Data on 10 individuals collected in a study are presented in table1.2

Table1.1: Diastolic and Systolic BP, Blood Glucose and income for 10 subjects

Subject no.

Gender Religion Diastolic BP

Systolic BP

Blood Glucose

Income(Tk)

1 Male 1 90 120 6.7 5000

2 Female 1 100 130 5.5 10000

3 Female 2 85 125 7.5 40000

4 Male 1 80 110 8.0 20000

5 Female 3 75 150 6.2 15000

6 Male 4 90 120 8.5 60000

7 Male 1 65 140 9.0 3000

8 Male 3 60 150 7.2 1000

9 Female 1 95 135 5.6 50000

10 Female 2 100 110 7.1 100000



Creating Variables:

To create variable(s) we need to follow the steps below:

1. On the bottom of left hand corner of the Data Editor Window simply click on Variable View

(Figure 1.2)

2. In the space for Name, type the desired variable name, this can be no more than 8 characters

in length. The first character must be alphabetic; the remaining characters can be alphabetic and /

or numeric, and no spaces can appear in the name. So, in this case, let’s type Name.

3. We should then through the relevant columns for that particular variable.

4 Click on the gray portion following String.

Figure 1.2: Variable View Window.



Functions of the columns and the default values of a variable view window:

Default values

a. Type: Allows defining the type of variable, Numeric

b. Width: Total number of characters, 8

c. Decimals: Number of characters beyond the decimal point, 2

d. Label: A name for the variable that can be up to 120 characters long and can include spaces (which variable names cannot). If a variable label is entered, the label will be printed on charts and reports instead of the name, making them easier to understand.

Allows to list a more extensive label for our variable. Eight character variable names are difficult

to remember, and we always exercise the option of listing a more descriptive label.

None

e. Value: Allows providing labels for the various label of a variable. None

It provides a key to translate numeric data.

To change the variable label, click on the Labels… button. This will open the Define Labels: dialog box. Enter the appropriate information into the fields. When done, click on the Continue button.

f. Missing values: This field indicates which subset of the data will not be included in the data set. To change this field, click on the Missing Values… button. This will open the Define Missing Values: dialog box. Enter the appropriate information into the fields. When done, click on the Continue button.

That Enables designate certain scores as missing. None



g. Columns: Allows changing the maximum number of characters in a column.

8

h. Align: Allows determining the alignment of column. Right

Measure: Allows determining the kind of scale for that particular variable. Scale

Nominal data: are categories that have no numerical meaning such as one's religious

denomination or city or residence. The values can't logically be added, subtracted, or even sorted.

Ordinal data: are categories also, but they can be sorted in some logical fashion such as class

(freshman, junior, senior).



.

Figure1.3: Variable type dialog box.

5. Click on label and type the Name of the respondent

6. If necessary perform other options such as modify the column width and whether the numbers

appear left justified, right justified, or centered.



Figure1.4: SPSS Data Editor with Value Labels dialog box.



Figure1.5: SPSS Data File showing the variables.



Figure1.6: SPSS Data Editor showing the values for different variables.

Descriptive Statistics:

Descriptive statistics includes the measures of both location (mean, median, mode etc.) and

dispersion (range, SD etc). The following are considered when computing descriptive statistics.

Mean and standard deviation are often used when data are assumed normal

Median and range are normally used in case of data containing extreme values

The mode is useful for nonnumeric data.

We shall describe the step-by-step procedures using data from example for computing

descriptive statistics.



Frequencies:

To begin, click on

Analyze

Descriptive Statistics

Frequencies

Figure: 1.7: SPSS data editor showing the path to the option Frequencies

Selecting variables:



1. Click on [Analyze => Descriptive Statistics => Frequencies] which gives Frequencies dialog

box (Figure 1.8)

2. Select the variables from the list on the left in the frequencies dialog box

3. Click on arrow to move the variable to the window on the right

Specify Statistics:

4. Select Statistics that yield Frequencies: Statistics dialog box. Select required statistics.

5. Click continued and finally OK

Figure: 1.8: Frequencies and Frequencies: Statistics dialog box



Figure:1.9: Output showing important statistics and Frequency table

What are the different types of windows in SPSS?W?

There are three kinds of windows in SPSS.

Data Editor Window: This is the first window that will appear when you start an SPSS session. The Data Editor Window is used to define and enter data and to perform statistical computations.

Output Window: The results of the statistical test appear in the Output Window.

Syntax Window: The Syntax Window can be used to keep a record of the operations that we perform on our data. This window is automatically opened when we click a Paste function.



Different SPSS windows and their functions:

Windows Function

Data Editor Used to define, enter, and edit data and to run statistical tests

Output Contains the results of the statistical procedures

Syntax Activate when we click on the Paste function and record of the operations

Documents

Lecture-1emrulmahmud.weebly.com/uploads/5/2/4/2/52421679/lecture-1.pdf · Md. Abdullah Al Mahmud Senior Lecturer Manarat International University Data: A data set is the organized