Why rotations
A large hackathon organiser guide, listed below, recommends science fair style judging: teams present at their tables as judges arrive, every project is seen by at least three different judges, and projects are staggered across judges rather than clustered. Its planning figure is about four minutes per judge visit, with the demo, questions, scoring and the walk to the next table inside that time.
The slot arithmetic
With 18 teams and 3 visits each, the rotation holds 54 visits. Spread over 6 judges that is 9 visits each, so the rotation needs at least 9 slots. At 4 minutes a slot that is 36 minutes of judging; the example adds 3 spare slots so there is room to move a visit when a demo overruns.
Worked example: 18 teams, 6 judges, 4 minute slots
An invented hackathon with 18 teams at tables A1 to A9 in the hall and B1 to B9 in the lab, and 6 judges with no categories, was given 12 slots of 4 minutes from 13:00 to 13:48, one judge at a table at a time, and 3 judges per team. The judge assigner filled 54 of 54 visits, gave every judge 9 teams, and broke 0 rules. Judge A's rotation:
| Time | Table | Room | Team |
|---|---|---|---|
| 13:00 to 13:04 | A2 | Hall | Team 2 |
| 13:04 to 13:08 | A1 | Hall | Team 1 |
| 13:20 to 13:24 | A9 | Hall | Team 9 |
| 13:24 to 13:28 | A8 | Hall | Team 8 |
| 13:28 to 13:32 | A7 | Hall | Team 7 |
| 13:32 to 13:36 | A6 | Hall | Team 6 |
| 13:36 to 13:40 | A3 | Hall | Team 3 |
| 13:40 to 13:44 | A4 | Hall | Team 4 |
| 13:44 to 13:48 | A5 | Hall | Team 5 |
Setting it up
Paste the teams as projects, with the table and room of each; the category column can hold the prize track. Paste the judges with the hours they are there. On the Rules tab, set the judges per project, switch on time slots, add a run of slots and set one judge at a table at a time. Assign, check the grid, lock anything a sponsor has asked for, and print the route sheets.
Common mistakes
- Judging rooms, so a team is only compared with the few teams that shared its room.
- Too few slots, so the rotation only works if nothing overruns.
- Two judges arriving at one table together when demos are meant to be one to one.
- A judge whose own company sponsored a team judging that team.
- Posting the rotation late, so teams leave their tables before their last judge arrives.
The same method runs a science fair with timed interviews; see judge route sheets and schedules.