Primary Data Analysis
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Transcript of Primary Data Analysis
ASSALAM O ALAIKUM .Guys hope you all enjoying,
Normally we deal with two kinds of data.
Primary data and secondary data
This is easy for us to analyze a numerical data, like I have profitability data of hundred
companies and this data are commonly known as secondary data. Secondary data collected form
secondary sources.
There is another kind of data which is known as primary data, so primary data is little bit
difficult and different form secondary data, (my own perceptions), we collect normally primary
data through questionnaire.
So let suppose I have a questionnaire through we will discuss about Primary data analysis. In the
following questionnaire I have three variables and each variable have different items (questions)
so, here we have need to reduce these questions into single variables, like turnover intension
have six items (questions) and justice have three item, let suppose if I take justice as dependent
variable while turnover intention as independent variables so I have to run 3 time regression
because of we have three dependent variables (because three items of justice), which is too hectic
So what I have to do for converting all the items of a variable into single variable, like I have
three item of justice, what I must do for merge all three items into single variable, which is
justice?
Hence, the simple method to reducing data into smallest summary is PRINCIPAL
COMPONENT ANALYSIS (PCA)
Why we use PCA?
1. To discover or to reduce the dimensionality of the data set.
2. To identify new meaningful underlying variable
3. To test theoretical questions through empirically.
From now let’s start. First of all we will conduct reliability test
Reliability test?
Reliability is the degree to which an assessment tool produces stable and consistent results. Test-
retest reliability is a measure of reliability obtained by administering the same test twice over a
period of time to a group of individuals.
Reliability through Cronbach's alpha
Cronbach's alpha is a measure of internal consistency, that is, how closely related a set of items
are as a group. It is considered to be a measure of scale reliability. Technically speaking,
Cronbach's alpha is not a statistical test - it is a coefficient of reliability (or consistency).
What must be the value of Alpha Coefficient to conclude that items are consisting or not?
Let suppose I have the alpha coefficient for the three items (justice questions) is .839, suggesting
that the items have relatively high internal consistency. (Note that a reliability coefficient of .70
or higher is considered “acceptable" in most social science research situations.) And here is also
another reference
Cronbach's alpha Internal consistency
α ≥ 0.9 Excellent
0.9 > α ≥ 0.8 Good
0.8 > α ≥ 0.7 Acceptable
0.7 > α ≥ 0.6 Questionable
0.6 > α ≥ 0.5 Poor
0.5 > α Unacceptable
Reference
George, D., & Mallery, P. (2003). SPSS for Windows step by step: A simple guide and
reference. 11.0 update (4th ed.). Boston: Allyn & Bacon.
How to write the results of your Cronbach’s alpha values in your article of thesis?
Table 1.Reliability of measurement
Constructs Valid number Number of items Cronbach’s alpha
Turnover intension 200 7 .778
Trust 200 3 .913
Justice 200 3 .920
Employees job satisfaction 200 9 .740
Table 1.Represent the estimated values of Cronbach’s coefficient alpha examined the reliability
and internal consistency of the measures. For the present sample, value of Cronbach’s alpha vary
from0.74 to 0.92 which indicates that each multi- item construct possesses high reliability
turnover intension (alpha = .778), trust (alpha = .913) justice (alpha = .920) employee job
satisfaction (alpha = .740) the high Cronbach’s alpha value for each construct implies that they
are internally consistent. In brief, the higher the Cronbach’s value of the construct the higher the
reliability is of measuring.
If you find Cronbach’s alpha acceptable then you can go further analysis otherwise not.
Like PCA, CORRELATION, REGRESSION ETC.
Steps for reliability test .analyze------scale----reliability and ok bellow is resulted file of
reliability test.
Step 2. Drag all items of your first variable (means drag all questions of your first variable
into right side box and ok(repeat same procedure for all your variables )
Step 3.resutls of reliability test for first variable. Check reliability of variables and write
results in above table form.
PCA
Now we are going toward PCA (principal component analysis), let suppose we have observe
reliability of all the items and we find reliability values of all items acceptable in this case
can conduct principle component analysis.
We will find two types of values in PCA, KMO and Bartlett's Test AND Eigen values.
Now why we use KMO?
The KMO measure of sampling adequate indicates the suitability of employing factor analysis.
The value of KMO varies between 0 and 1 a value of 0 indicates that there is larger dispersion in
the pattern of correlations hence, application of factor analysis become inappropriate. A value of
1 indicates that the patterns of correlation are relatively compact so the application of factor
analysis becomes appropriate. It is a general rule of thumb that a KMO value of 0.5 is poor and
0.6 is acceptable and value closer to 1 is better and more desire able further more values between
0.5 and 0.7 are mediocre, values between 0.7 and 0.8 are good values and values between 0.8
and 0.9 are great values above 0.9 are superb
Bartlett’s test sphericity
is conducted to check the significance of the relationship between the items of a construct. If
there is no relationship among the items of a construct then it will be pointless to go ahead with
the factors analysis. Bartlett’s test assumes a null hypothesis of no correlation. Generally, a p-
value <0.05 confirms the significance of the relationship among variables. In my table the p-
values of Bartlett’s test in the case of all constructs is less than 0.001 which provides evidence
against the null hypothesis of no correlation. So we can continue with factors analysis.
What values we should write for analysis in our thesis or article?
KMO and Bartlett's Test
Constructs Number
of items
Kaiser-Meyer-Olkin
Measure of Sampling
Adequacy.
Bartlett's
Test of
Sphericity
Bartlett's
Test of
Sphericity sig
Turnover intension 7 .690 771.529 .000
Trust 3 .685 674.495 .000
Justice 3 .656 634.317 .000
Employees job satisfaction 9 .858 1384.0 .000
ANALYZE----DIMENTION REDUCITON----FACTOR and ok
Step 1.
Step 2.drag all items of your first variable and note, don’t include informational variables
like gender, age etc, and below is detail about what u must click in descriptive, extraction
rotation etc. and after click all required options do ok.
Descriptive = click KMO
Extraction =no need to change any thing
Rotation=click to varimax
Scores =save as variable
Option =no need to change any thing
Step 3.
We have need of
KMO and Bartlett’s
test values, and
significance values
Step 4. You can see all five items of first variables merge and adopt a form of single
variable now go to your spss file and give the original name of your variable to new
variables , from this method convert all the variables in single variables.
What must be the KMO values?
I HAVE ALREADY TOLD ABOUT THE KMO VALUE AND BARTLET TEST VALUE
IN ABOVE PARAGHARPH.
REFRENCE.Hutcheson, G. and Sofroniou, N. (1999), The multivariate social scientist. London: Sage.
Eigen values and total variance?
Frist of all how to write Eigen values
Construct Components Total % of variance Cumulative %
Turnover Comp1 3.220 64.404 64.404
Trust Comp1 2.734 91.126 91.126
Justice Comp1 2.964 89.791 89.791
Job satisfaction Comp1 6.245 56.774 56.774
Faci_1 is new variable which is produce after
PCA, now u must give name to this variable like
you can write here justice, customer satisfaction
etc means assign name of your variable, in label
also write the name of this new variable.
Note: Constructs means our variables, component means when we run PCA
let suppose when I run PCA for first variable we saw only one variable
extract or develop , it’s not necessary that all the items produce one
component ,let suppose justice items produce 2 component means two
variable then we will write like this and remaining items same
Construct
Justice Comp1
Comp2 If I interpret above results, turnover having one component which have 64% information
of all the items of justice variables. And remain same interpretation, and if two component,
then let suppose justice have two component and one component have information of all
items x% while component 2 having information of all items of justice x%.
Correlation
Let suppose we have run PCA and summarized the items of all variables into only four
variable
The correlation analysis has been used to confirm mutual association among the items of each
construct. Then main purpose of correlation is to check the relationship strength means strong
relation or weak or moderate etc.
1. If value comes less than 0..34 we will say weak relationship among variables
2. If value comes 0.34-----.74 moderate relation
3. If value comes more than .74 strong relation
In the following window we can see 23 items are summarize into four variables , now we
will check correlation among variables , now u have no need to examine all the items u
can use only these four variables
Steps for checking correlation. Analyze --- correlate ---bivariate
Following window is showing results of correlation among variables
Here we can see that we have convert all 23
items not only four variables
I have use
only new four
variables not
all items. And
ok
How to write results of correlation
Turnover
intentions
Trust Justice Employees job
satisfaction
Employees turnover
intentions
1
Trust .134**
1
Justice .129* .798
** 1 .
Employees job
satisfaction
.891**
.524
**
.241* 1
Last regression analysis
In the following window write your dependent variable and independent variable
Your dependent
variables and all
independent
variable
Let suppose I write my T variable as dependent and other variables as independent
variable.
RESUTLS OF REGRESISON BEST OF LUCK
To see
autocorrelation in
your data you can
click on statistics and
D.W VALUE
Questionnaire used for interpretation
1. Disagree 2.Strongly disagree 3. Neutral 4. Agree 5. Strongly Agree
Turnover Intension
1 Employees understand specific needs of customers (empathy). 1 2 3 4 5
2 Employees are able to “put themselves in the customers’ place”
(empathy).
1 2 3 4 5
3 Employees are able to “tune in” to each specific customer (empathy). 1 2 3 4 5
4 Employees “surprise” customers with their excellent service (excellent
performance).
1 2 3 4 5
5 Employees do more than usual for customers (excellent performance). 1 2 3 4 5
6 Employees deliver an excellent service quality that is difficult to find in
other organizations (excellent performance).
1 2 3 4 5
Justice
1 Justice between the employees is main element in organization
1 2 3 4 5
2 Justice improve the efficiency of organization
1 2 3 4 5
3 Justice is key determent of value addition in organization
1 2 3 4 5
Employees work engagement
1 At work, I feel full of energy. 1 2 3 4 5
2 In my job, I feel strong and vigorous. 1 2 3 4 5
3 When I get up in the morning, I feel like going to work. 1 2 3 4 5
4 I can continue working for very long periods at a time. 1 2 3 4 5
5 In my job, I am mentally very resilient. 1 2 3 4 5
6 At work, I always persevere, even when things do not go well 1 2 3 4 5
7 I find the work that I do full of meaning and purpose. 1 2 3 4 5
8 I am enthusiastic about my job. 1 2 3 4 5
9 My job inspires me. 1 2 3 4 5
10 I am proud of the work I do. 1 2 3 4 5
11 I find my job challenging. 1 2 3 4 5
12 Time flies when I’m working. 1 2 3 4 5
13 .When I am working, I forget everything else around me. 1 2 3 4 5
14 I feel happy when I am working intensely. 1 2 3 4 5