Choose a name and parent court: The court must be placed in the tree structure below:
Given that we attempt to create a court where jurors are vetted, none of the V1 courts shown are apt for us. The most reasonable design seems to be placing the Lido court as a child of the Blockchain Technical court.
To learn more about this court, see historical data on Kleros Dashboard.
Redact a policy—a document meant to guide jurors on how to solve cases, uploaded on IPFS. An example for the Blockchain Technical court:
{
"name":"Technical",
"description":"**Court Purpose**\\n\\nThis court serves to arbitrate blockchain disputes of a technical nature. This can include:\\n\\n- Verifying that a smart contract meets a defined standard. \\n\\n- Verifying that a proposed contract call is the technical translation of a decision taken by governance.\\n\\n**Example**\\n\\n- A dispute on whether or not a token should be given a badge indicating that it satisfies ERC20. \\n\\n- A dispute on whether or not a proposed Kleros governor call matches the decision which has been voted through governance.",
"summary":"**Policies:** \\n\\n- Disputes in this subcourt should only be of technical nature. ",
"requiredSkills":"A high understanding of blockchain technology, smart contract, solidity language and Ethereum ABI is required."
}
Estimate some metrics needed for the calculation of parameters. Note that after a court is created one can create further governance proposals to update the parameters in case adjustments are needed.
<aside> ℹ️ Why are these metrics needed? They are used to compute court parameters that respect the following criteria:
**- Honest participation should be profitable.
- Voting without making an effort to analyze a case should be unprofitable.
- Reward for a correct vote should cover gas costs even if there is an extreme spike in gas prices (potentially less relevant as we migrate to L2s).**
The mathematical details can be found in the aforementioned article: Parameterization for Kleros courts.
</aside>
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Typical effort
erequired to evaluate cases: value is given in a currency or stablecoin, and corresponds to a fair minimum compensation to be paid to each juror for analyzing an average case in the court.-
How do we select the $e$ parameter? See comments by the Kleros team:
Generally, if we have a good idea of what a typical case will look like/some sample cases we can get community feedback on what they think the (average) compensation to judge those cases should be. Sometimes if a task has clear analogs to web2 type micro-tasks (e.g. content moderation) we can use the typical compensation of those as a starting point.
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Following the above, note that the Blockchain Technical court uses $e = 80$ EUR. We can use this as a starting point, and if it is found—for example, in a testnet phase—that the tasks for this court are more effort-intensive, then this parameter can be tweaked.
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Degree of subjectivity
- How often will jurors who make honest efforts agree with community consensus? Denote as
p. One can estimate it as the historical coherence rate of a similar court (84% for the Blockchain Technical court) - How often will jurors who don't make effort be able to guess community consensus? Denote as
t. Must have 50% as lower bound (random vote)—a common starting prior is $t=0.6$.
- How often will jurors who make honest efforts agree with community consensus? Denote as
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Risk-aversion factor $
\\lambda$: λ=1 is risk neutrality, λ>1 is risk aversion. This parameter seems to have been introduced as a response to jurors’ complaints of the risk (i.e. variance) in payouts after participating in court, despite the expected return being positive on a large enough timescale. According to the Kleros team, recent court updates have chosen values of $\lambda$ slightly greater than 1 (at the time of writing $\lambda = 1.05$). The team also mentions:That said, if you get feedback that the people who wind up being jurors for your disputes are particularly risk-averse, it can make sense to update that value accordingly.
Once all the metrics above have been gathered, we can use Kleros’ Calculator for Court Parameters to compute the correct parameters. A complete list of what is computed is given below:
feeForJuror: the minimum amount that a coherent juror will earn. Thus, a dispute requires paying the court a fee equal to feeForJuror*n, where $n$ is the number of jurors.minStake: minimum value of PNK that must be staked in order for a juror to participate in a given court.- Remark: minStake(court) ≥ minStake(parent court).
alpha: ratio between the vote stake and minStake. In other words, the percentage of minStake actually at stake per vote.
The following parameters are not computed indirectly—they are assigned manually.
hiddenVotes: If set equal to 1, the court uses its commit-reveal phase. If set equal to 0, votes are public.jurorsForCourtJump: from the blogpost above: “determines how many times a case can be appealed in a given court. Namely, if the number of jurors in the current round is less than jurorsForCourtJump, if there is another appeal the same court will consider the case just with a larger panel of jurors. On the other hand, if the number of jurors in the current round is greater than or equal to jurorsForCourtJump, then a subsequent appeal round will take place in the parent court of the current court.”timesPerPeriod: establishes how long to wait during evidence, voting, and appeal periods.