An affinity diagram is used in software quality engineering to organize many ideas, issues, requirements, or causes into meaningful groups. The first step is to collect raw input through an interview, focus group, or brainstorming session. After the ideas are collected, the team groups similar statements together based on natural relationships. Once groups are formed, the team identifies themes or headings that describe each group. The final step is to draw or document the affinity diagram so the organized information can be reviewed, communicated, and used for analysis. Drawing the diagram before collecting or grouping ideas would be incorrect. Identifying themes before grouping statements is also premature because themes should emerge from the grouped data. Therefore, the correct sequence is 1, 3, 4, 2.