Which of the following statements about Delphi method is true –
Delphi method 

Delphi method is a systemic, interactive forecasting method which relies on a panel of independent experts.
The first round of the delphi method essentially involves development of a questionnaire that are posted to members of the team experts.
The carefully selected experts answer questionnaires in two or more rounds.
After each round, a facilitator provides an anonymous summary of the experts forecasts from the previous round as well as the reasons they provided for their judgment.
Thus, experts are encouraged to revise their earlier answers in light of the replies of other members of the panel.
It is believed that during this process the range of the answers will decrease and the group will converge towards the "correct" answer.
Finally, the process is stopped after a pre-defined stop criterion (e.g. number of rounds, stability of results) and the mean and median scores of the final rounds determine the results.

Principal of Delphi 

Delphi is based on the principal that forecast from a structured group of experts are more accurate than those from unstructured groups or individuals.
The technique can be adapted for use in face-to-face meetings, and is then called mini-Delphi or Estimale - Talk - Estimate (ECE).
Delphi has been widely used for business forecasting and has certain advantages over another structured forecasting approach called, prediction markets.

Key characteristics of Delphi method 

The following key characteristics of the Delphi method help the participant to focus on the issues at hand and separate Delphi from other methodology -

1. Structuring of information flow

The initial contributions from the experts are collected in the form of answer of questionnaires and their comments to these answers.
The panel director controls the interactions among the participants by processing the information and filtering out irrelevant content.
This avoids the negative effects of face-to-face panel discussion and solves the usual problems of group dynamics.

2. Regular feedback

Participants comment on their own forecasts, the responses of others and on the progress of the panel as a whole.
At any moment they can revise their earlier statements.
While in regular group meetings participants tend to stick to previously stated opinions and often conform too much to group leader, the Delphi methods prevents it.

3. Anonymity of the participants

Usually all participants maintain anonymity.
Their identity is not revealed even after the completion of the final report.

This stops them from dominating others in the process using their authority or personality, frees them to some extent from their personal biases, minimizes the "bandwagan effect" or "halo effect", allows them to freely express their opinions, encourages open critique and admitting errors by revision earlier judgments.
Method involves formation of a team to undertake and monitor a Delphi on a given subject
Selection of one or more panels to participate in the exercise. Customarily, the panelists are experts in the area to be investigated.
The first round in the Delphi method involves development of a questionnaire
All are true