Analysis Related to Breeding Researches - Research Methodology - page 298

(continued)
PATH ANALYSIS
VARIABLES FOR PATH ANALYSIS (FIRST DEPENDENT)
12345
GENETIC ADVANCE ¼ 0.54798203E+02
GENOTYPIC PATH
MATRIX OF DIRECT AND INDIRECT EFFECTS
DIRECT EFFECTS ON MAIN DIAGONAL
2 0.323 0.314 0.587 0.080

3 0.068 1.501 1.831 0.360

4 0.101 1.462 1.881 0.284

5 0.048 1.012 1.000 0.534

RESIDUAL 0.2048

PHENOTYPIC PATH
MATRIX OF DIRECT AND INDIRECT EFFECTS
DIRECT EFFECTS ON MAIN DIAGONAL
2

¼

0.330 0.241 0.492 0.068

3 0.068 1.166 1.537 0.312

4 0.103 1.133 1.581 0.246

5 0.049 0.785 0.841 0.463

RESIDUAL ¼ 0.2293

themselves, the question arises on how to work
out the direct influence of a particular variable/
character on the response variable/character and
the effects of the variable/character through other
variables/characters because of their interrela-
tionship. Path coefficient analysis is one of the
possible answers. In a path coefficient analysis,
there are at least two groups of variables: the
independent or exogenous variables and the
dependent or endogenous variables. Path coeffi-
cients indicate the direct and indirect effects of
the variables on another variable. A path diagram
is a flowchart to represent the direction of effects
of different variables on the dependent variables
(Fig. 11.1 ).
In the above diagram,

11.3 Path Analysis

In agriculture and allied fields, including social
sciences, the researchers come across with a
number of variables at a time, in which different
variables are not only related with response
variables but also related among themselves. As
such, the degree of association which we
measured through the correlation coefficient
may not provide the actual intensity of relation-
ship because other variables might have
influenced both variables under consideration.
For example, the paddy yield is governed by
different yield components like the number of
hills per square meter, the number of tillers per
hill, the number of panicle bearing tillers per hill,
the length of panicle, and the number of grains
per panicle. All these components are influencing
the yield. The yield components are not only
individually correlated with yield but also
correlated among themselves. Similarly, while
studying the physical fitness of human being,
one considers the body characteristics like height
and body weight of body, leg length, and BMR.
In socioeconomic studies, the social status of a
person is influenced by his/her age, education,
family size, income, expenditure, involvement in
social program, etc.
As the variables/characters are correlated not

X 1 , X 2 , and X 3 are the

exogenous independent variables, and X 5

are the endogenous dependent variables. Here
the variable

X 4 and

X 5 is dependent not only on X 4 but

also on the independent variables X 1 , X 2 , and X 3 .

X 4 is dependent

Similarly, the dependent variable

on X 3 . The direction of arrows

indicates the response variable by the causal
variables. It may be noted that there may be
both-way arrows among the exogenous indepen-
dent variables, but there are one-way arrows
from the exogenous independent variables to
the endogenous variables. Thus, for

X 1 , X 2 , and

X 5 , the vari-

able X 4 is independent but it is not exogenous.

The both-way arrows mean the variables are