Mediation

Muhammad Saeed Aas Meo , Superior University Pak

A Case where we have only one independent variable, one dependent variable and one mediating variable

Special thanks to my respected teachers, Dr.Muhammad Ilyas, Mam Shazia Kusar PhD.

Candidate (Superior University Lahore Pakistan).

Mediation between independent and dependent variables:

First of all I would like to define what is mediating variable.in simple words mediating variable

works like a bridge between two or more than two variables. Mediation is a hypothesized causal

chain in which one variable affects a second variable that, in turn, affects a third variable .Like

we think that teachers degree positively affect students satisfaction, obvious if teachers are

highly qualified then student will be satisfied ,but on the other hand we think student satisfaction

also dependent on student care.it is possible may be students are not satisfied with the teachers

degree but they are satisfy with the care of teacher (S.C) , so here we will consider students care

as mediating variable and we shall see either student care mediate relation between degree and

student satisfaction or not.

We divide mediation into two main kinds, partial mediation and full mediation. Following is chart

which is showing that we are taking in example three variables as independent, mediating and

dependent variable.

indipendent variabel

•Degree

medeating variabel

•student care

dependent variable

•student satisfaction


Now hypothesis will be like this:

1. HI: Teachers degree effects student satisfaction

2. HI: Student care meditates the relationship between teachers degree and student

satisfaction.

Step one

In first step first we will check either mediation exists or not between projected variables

and then in next step we will differentiate partial mediation and complete or full

mediation. Following is the way of checking mediation. AS we have three total variables

so we shall run three time regression and if we shall find significant relationship among

variables then we shall conclude that there is mediation exist.

Run regression (take teachers degree as independent variable while student care as

dependent variable

Degree--------------------------------------- Student care (significant relationship)

Run again regression but this time take student care as independent variable and student

satisfaction dependent variable.

Student Care------------------------------- student satisfaction (Significant

relationship)

Again run regression now degree independent variable and student satisfaction as

dependent variable.

Degree-------------------------------------- student satisfaction (significant relationship)

D-------S.C

S.C------S.S

D--------- S.C

If all three regression results produce significant relationship then we call it there is

mediation among variables ,if regression results don’t produce significant results

then we can say mediation doesn’t exist (although this is not always true; see

MacKinnon, Fairchild, & Fritz, 2007)

Or more concise if independent variable and mediating variable affect dependent

variable significantly then we can say there is mediation among proposed variables

.

Here we assume that I have run regression and following are results of regression and all

variable are affecting dependent variable significantly. Here see degree affecting Student

care and Student care Affecting Student satisfaction, while degree directly also affecting

Student satisfaction , /so above condition fulfill that is all the regression results are

significant or independent and mediating variables are significant associate with dependent

variable so we can that say there is mediation among variables.

Degree S.C S.S


Now next step is partial mediation exists or fully mediation exists.

The following diagram conforming partial mediation because of degree directly and

significantly affecting student satisfaction. While student care also affecting student

satisfaction so here you can conclude, in simple words, you can say all the effect of

independent variable is not going toward dependent variable through mediating variable.

If you will quiet the or drop mediating variable , in this case still relationship will be exist

but speed or you can say strength of relationship may slow because mediating variable

also effecting dependent variable and was significantly associate with independent

variable. Whereas in full mediation if you drop mediating variable ,relationship between

dependent and independent also become zero, the reason is that in full mediation

independent variable directly not affect dependent variable ,but through mediating

variable so when you will quit mediating variable automatically bridge will demolish and

link drop.

Partial mediation

If dependent variable and mediating variable significant affect dependent variables then

we call it partial mediation. Here following we have two graphical examples.

Consider a variable Degree that is assumed to cause another variable S.Satisfaction. The variable

Degree is called the causal variable and the variable that it causes or S. Satisfaction is called the

outcome. In diagrammatic form, the unmediated model is. Path c in the above model is called

the total effect.

The effect of Degree on S.Satisfaction may be mediated by a process or mediating

variable Student care , and the variable Degree may still affect S.Satisfaction. The

mediated model is

(These two diagrams are essential to the understanding of this page. Please study them carefully!) Path c' is called the direct effect. The mediator has been called an intervening or process variable. Complete mediation is the case in

Degree Satisfaction c

Degree Satisfaction

Student care


which variable Degree no longer affects S.Satisfaction after student care has been controlled and so path c' is zero( means without student care or mediating variable no relationship between independent and depend variables that’s why we call it full mediation ). Partial mediation is the case in which the path from Degree to S.Satisfaction is reduced in absolute size but is still different from zero when the mediator is introduced.

Degree

Student care

Student satisfaction

Significant

relationship

Significant relationship

Partial mediation = direct +indirect effect on dependent variable.

IV DV

MV


Full mediation

Maximum evidence for mediation, also called full mediation, would occur if inclusion of the

mediation variable drops the relationship between the independent variable and dependent

variable.

Complete mediation is the case in which variable Degree no longer affects S.Satisfaction

after student care has been controlled and so path c' is zero( means without student care

or mediating variable no relationship between independent and depend variables that’s

why we call it full mediation ) (David A. Kenny

November 12, 2015).again in complete mediation mediating variable is necessary to build

link between two variables and if we quit mediating variable then association will be zero

between dependent and independent variables.

Here In the following screenshot degree (I.V) directly not affecting student satisfaction

(D.V), while degree significantly associates with student care (M.V) and student care

significantly associate with student satisfaction.So here we can conclude that if we quiet

mediating variable between independent and dependent then relationship will be zero and

but if we include mediating variable then independent variable effect will go through

mediating variable toward dependent variable.

Best of luck in next exercise I’ll show you how to deal if we have more than two independent variables

and more than one mediating variables and more than one dependent variable. And soon ill upload

video of mediation.

Insignificant

relationship

Degree significantly

associate with S.C

S.C significantly

associate with S.S

Documents

Mediation