Wide-Band Delphi
Wide-Band Delphi is a variation of the classical Delphi technique, adapted to include more extensive communication and collaboration among the participants. It aims to reach a more accurate and agreed-upon estimate by reconciling widely varying initial estimates through iterative rounds of estimation and discussion.
Core Steps in Wide-Band Delphi
Initial Anonymous Estimates: Similar to the traditional Delphi technique, experts individually and anonymously provide their initial estimates for the task or product backlog item.
Compilation of Estimates: All the estimates are compiled and summarized, often showing the range, median, and mode of the estimates.
Group Discussion: Unlike traditional Delphi, where feedback is mainly written and participants remain anonymous, Wide-Band Delphi allows for direct discussion among experts. This can happen in a face-to-face meeting, virtual conference, or other collaborative forums.
Rationale Sharing: Those who provided the highest and lowest estimates are given an opportunity to share their reasoning. This helps in uncovering hidden assumptions, overlooked risks, or additional context that may affect the estimate.
Re-Estimation: Experts revise their estimates based on the discussion and any new insights gained.
Iteration: The process of summarization, discussion, and re-estimation is repeated until a convergence of estimates is achieved.
Advantages
Improved Accuracy: The increased bandwidth of communication allows for better understanding and therefore more accurate estimates.
Enhanced Team Collaboration: Open discussions enable team members to share insights, reducing the likelihood of overlooking key factors.
Quick Convergence: The iterative approach, coupled with open discussions, usually leads to quicker convergence compared to traditional Delphi.
Disadvantages
Time-Consuming: Because it involves more discussion, it can be more time-consuming compared to traditional Delphi.
Potential for Bias: The anonymity is compromised to some extent, which may introduce bias or influence from dominant personalities.
Applicability
Complex Projects: Useful for tasks that are complex and where initial estimates can vary widely.
Expert-Led Environments: Best suited for situations where a variety of experts contribute to the project and their collective wisdom is valued.
Agile Methodologies: It can be effectively integrated into Agile frameworks where iterative estimation and re-estimation are common.
Wide-Band Delphi combines the structured, anonymous input of the Delphi technique with more open communication to arrive at reliable estimates. Whether applied formally or informally, it offers a balanced approach to harness collective expertise while allowing for discussion and clarification.