Group decision-making (also known as collaborative decision-making) is a situation faced when individuals collectively make a choice from the alternatives before them. Discussion: it is an important phase, because members of group expose their ideas, and they put all kind of information about the problem, and exchanging and processing the information.

1. Collectivedecision
theory
 Group decision-making (also known as collaborative
decision-making) is a situation faced when individuals
collectively make a choice from the alternatives before
them.
 Discussion: it is an important phase, because members
of group expose their ideas, and they put all
kind of information about the problem, and exchanging
and processing the information.

2.  Various models that focus on different stages of
decision making are
problem identification,
solution development,
Analyzing alternative,
Implementing alternative,
Evaluating decision effectiveness,
And also, has determined that the union of the efforts of
each group member can achieve a common goal.

3.  Some researchers have argued that decisions made in a
group are better than decisions made individually and
also large groups make better decision.
 Committee members do not know which of two
alternatives is the best.
 The collective decision help to achieve Efficiency goal.

4. Role of collective
decision
 Social choice theory is theoretical framework for
analysis of combining individual opinions, preferences,
interests, or welfares to reach a collective decision or
social welfare in some sense.
 There is social choice problems, which deals with
methods of marshalling information, particularly those
relating to the people involved, to arrive at correct
social judgments or acceptable group decisions.

5.  The natures of the possible informational inputs vary,
as do the required outputs of judgments, decisions, or
the required means of settlement.
 This relates to distinctions among structures such as
 social welfare functions,
 social decision functions,
 social choice functions or
 functional collective choice rules,

6. Why study collective decision
making
 The attraction of these theme is that it appears to stand
at across road in social science ,raising positive and
normative issues of great complexity in various
disciplines.
 Normative: men all agree that human decision are
imperfect and that we need better decision analytically,
it is possible to separate the moral quality of decision
and the rational quality of decision.

7.  Positive : this involves on the one hand individual
psychology on the other hand the disciplines which
study process at work in collectivities of various kinds,
such as
Social psychology,
Social anthropology,
Sociology,
Administration ,
Political science , and
History
Such inquiries are concerned with power and
process in collective decision .