--- tags: Reports --- # Sybil Report on Gitcoin Grants Rounds 12 ## Summary An total of 27.9% of the Gitcoin users, representing 21.7% of the contributions, were flagged during R12. The Sybil Incidence during this round is significantly higher than R11, with an estimate of being 2.6x higher (lower / upper boundaries being 1.6x to 5.1x). ## Links - Past reports - GR11: https://hackmd.io/kOEbdDNeSdCkYXGY2wJExQ - GR10: https://hackmd.io/XdCMH5DtRHyPNLCGDFZ-oQ - GR09: https://hackmd.io/smLQ-QXdTse2dz1c6-Z85w ## Parameters Algorithm Aggressiveness: 30% Threshold for marking human evals as "Sybil or "Not Sybil": 90% :::info Algorithm Aggressiveness tunes how much sensitive / specific the flagging model should be. When it is set to 50%, then it will be optimized for accuracy, while closer values to 0% means that it will be optimized for minimizing false detection rate ::: ## Statistics ### Sybil Incidence & Detection #### Sybil Incidence *Estimated Sybil Incidence per Evaluation Round* ![](https://i.imgur.com/cBGSSEQ.png) ___ Scenario A: Incl. squelches - **Estimated Sybil Incidence: 26.3% (between 24.2% and 28.4%, 95% CI)** - Estimated Sybil Users: 7635 (between 7025 and 8245, 95% CI) ___ Scenario B: No squelches - **Estimated Sybil Incidence: 16.4% (between 14.5% and 18.3%, 95% CI)** - Estimated Sybil Users: 4753 (between 4203 and 5304, 95% CI) ___ - **Flagged Users Fraction: 27.9%** - Flagged Sybil Users: 8100 #### Sybil Flags - ML generated flags: 3986 - Heuristic generated flags: 2811 - Human provided flags: 1571 (at most 850 squelches) - Total flags: 8100 #### Sybil Evaluations *Relative distributions of scores per category* ![](https://i.imgur.com/aK39YHV.png) Total users evaluated by humans: 4997 (17.2% of total) Users marked as true by humans: 1571 (31.4%) Users marked as false by humans: 3426 (68.6%) ___ Total users evaluated by heuristics: 2811 (9.7% of total) Users marked as true by heuristics: 2543 (90.5%) Users marked as false by heuristics: 268 (9.5%) ___ Total users evaluated by algorithms: 21179 (73.1% of total) Users marked as true by algorithms: 3986 (18.8%) Users marked as false by algorithms: 17193 (81.2%) ___ Total users evaluated: 28987 (100.0% of total) Users marked as true: 8100 (27.9%) Users marked as false: 20887 (72.1%) ___ *Comparison between Evaluation / Prediction / Aggregate score* ![](https://i.imgur.com/l1B3F1H.png) ### Summary Statistics on Scenarios #### Contributors Total Contributions (original): 528233 Total Contributions (modified): 528233 Total Contributions (removed): 114923 ___ Matched Contributions (original): 528233 Matched Contributions (modified): 413310 Matched Contributions (removed): 0 Change: 114923 Total Contributors (original): 28416 Total Contributors (modified): 20888 Total Contributors (removed): 7529 ___ Sum of USDT Amount (original): 4981968.65 Sum of USDT Amount (removed): 621376.66 ___ Median of Median USDT Amount per User (original): 2.00 Median of Median USDT Amount per User (modified): 2.00 Median of Median USDT Amount per User (removed): 1.60 ___ Median Contribution Count per User (original): 10.00 Median Contribution Count per User (modified): 10.00 Median Contribution Count per User (removed): 8.00 ___ Mean Count per User (original): 18.59 Mean Count per User (modified): 25.29 Mean Count per User (removed): 15.26 ___ *Histogram of the Contribution per User aggregates* ![](https://i.imgur.com/XptVSL4.png)