simple scoring system for prompts and ranks

This commit is contained in:
Alexander Mattick
2022-12-25 13:39:21 +01:00
parent 76f7ed813b
commit 58885f1e9b
+121 -11
View File
@@ -1,9 +1,10 @@
# -*- coding: utf-8 -*-
from dataclasses import dataclass
from dataclasses import dataclass, replace
from typing import Any
import numpy as np
import numpy.typing as npt
from scipy.stats import kendalltau
@dataclass
@@ -18,7 +19,15 @@ class Voter:
uid: Any
num_votes: int
num_good_votes: int
total_points: int
num_prompts: int
num_good_prompts: int
num_rankings: int
num_good_rankings: int
#####################
voting_points: int
prompt_points: int
ranking_points: int
def voter_quality(self):
return self.num_good_votes / self.num_votes
@@ -26,11 +35,22 @@ class Voter:
def is_well_behaved(self, threshhold):
return self.voter_quality() > threshhold
def total_points(self, voting_weight, prompt_weight, ranking_weight):
return (
voting_weight * self.voting_points
+ prompt_weight * self.prompt_points
+ ranking_weight * self.ranking_points
)
def score_update(new_vote: int, consensus: npt.ArrayLike, voter_data: Voter) -> Voter:
def score_update_votes(new_vote: int, consensus: npt.ArrayLike, voter_data: Voter) -> Voter:
"""
This function returns the new "quality score" and points for a voter.
I.e. a voter casts a vote on a question.
This function returns the new "quality score" and points for a voter,
after that voter cast a vote on a question.
This function is only to be run when archiving a question
i.e. the question has had sufficiently many votes, or we cann't get more than "K" bits of information
The consensus is the array of all votes cast by all voters for that question
We then update the voter data using the new information
@@ -45,21 +65,111 @@ def score_update(new_vote: int, consensus: npt.ArrayLike, voter_data: Voter) ->
# produces the ranking of votes, e.g. for [100,300,200] it returns [0, 2, 1],
# since 100 is the lowest, 300 the highest and 200 the middle value
consensus_ranking = np.argsort(np.argsort(consensus))
new_points = consensus_ranking[new_vote] + voter_data.total_points
new_points = consensus_ranking[new_vote] + voter_data.voting_points
# we need to correct for 0 indexing, if you are closer to "right" than "wrong" of the conensus,
# it's a good vote
new_good_votes = int(consensus_ranking[new_vote] > (len(consensus) - 1) / 2) + voter_data.num_good_votes
new_num_votes = voter_data.num_votes + 1
return Voter(voter_data.uid, new_num_votes, new_good_votes, new_points)
return replace(voter_data, num_votes=new_num_votes, num_good_votes=new_good_votes, voting_points=new_points)
def score_update_prompts(consensus: npt.ArrayLike, voter_data: Voter) -> Voter:
"""
This function returns the gain of points for a given prompt's votes
This function is only to be run when archiving a question
i.e. the question has had sufficiently many votes, or we cann't get more than "K" bits of information
Parameters:
consensus (ArrayLike): all votes cast for this question
voter_data (Voter): a "Voter" object that represents the person that wrote the prompt
Returns:
updated_voter (Voter): the new "quality score" and points for the voter
"""
# produces the ranking of votes, e.g. for [100,300,200] it returns [0, 2, 1],
# since 100 is the lowest, 300 the highest and 200 the middle value
consensus_ranking = np.argsort(np.argsort(consensus)) - len(consensus) // 2
delta_votes = np.sum(consensus_ranking * consensus)
new_points = delta_votes + voter_data.prompt_points
# we need to correct for 0 indexing, if you are closer to "right" than "wrong" of the conensus,
# it's a good vote
new_good_prompts = int(delta_votes > 0) + voter_data.num_good_prompts
new_num_prompts = voter_data.num_prompts + 1
return replace(
voter_data,
num_prompts=new_num_prompts,
num_good_prompts=new_good_prompts,
prompt_points=new_points,
)
def score_update_ranking(user_ranking: npt.ArrayLike, consensus_ranking: npt.ArrayLike, voter_data: Voter) -> Voter:
"""
This function returns the gain of points for a given ranking's votes
This function is only to be run when archiving a question
i.e. the question has had sufficiently many votes, or we cann't get more than "K" bits of information
we use the bubble-sort distance (or "kendall-tau" distance) to compare the two rankings
we use this over spearman correlation since:
"[Kendall's τ] approaches a normal distribution more rapidly than ρ, as N, the sample size, increases;
and τ is also more tractable mathematically, particularly when ties are present"
Gilpin, A. R. (1993). Table for conversion of Kendall's Tau to Spearman's
Rho within the context measures of magnitude of effect for meta-analysis
Further in
"research design and statistical analyses, second edition, 2003"
the authors note that at least from an significance test POV they will yield the same p-values
Parameters:
user_ranking (ArrayLike): ranking produced by the user
consensus (ArrayLike): ranking produced after running the voting algorithm to merge into the consensus ranking
voter_data (Voter): a "Voter" object that represents the person that wrote the prompt
Returns:
updated_voter (Voter): the new "quality score" and points for the voter
"""
bubble_sort_distance, p_value = kendalltau(user_ranking, consensus_ranking)
# normalize kendall-tau from [-1,1] into [0,1] range
bubble_sort_distance = (1 + bubble_sort_distance) / 2
new_points = bubble_sort_distance + voter_data.ranking_points
# it's a good ranking if the likelihood that the consensus ranking and the
# user ranking are related
new_good_rankings = int(p_value < 0.5) + voter_data.num_good_rankings
new_num_rankings = voter_data.num_rankings + 1
return replace(
voter_data,
num_rankings=new_num_rankings,
num_good_rankings=new_good_rankings,
ranking_points=new_points,
)
if __name__ == "__main__":
demo_voter = Voter("abc", 10, 2, 6)
demo_voter = Voter(
"abc",
num_votes=10,
num_good_votes=2,
num_prompts=10,
num_good_prompts=2,
num_rankings=10,
num_good_rankings=2,
voting_points=6,
prompt_points=0,
ranking_points=0,
)
new_vote = 3
consensus = np.array([200, 300, 100, 500])
print(demo_voter)
print("best vote", score_update(new_vote, consensus, demo_voter))
print("best vote ", score_update_votes(new_vote, consensus, demo_voter))
new_vote = 2
print("worst vote", score_update(new_vote, consensus, demo_voter))
print("worst vote ", score_update_votes(new_vote, consensus, demo_voter))
new_vote = 1
print("medium vote", score_update(new_vote, consensus, demo_voter))
print("medium vote ", score_update_votes(new_vote, consensus, demo_voter))
print("prompt writer", score_update_prompts(consensus, demo_voter))
print("best rank ", score_update_ranking(np.array([0, 2, 1]), np.array([0, 2, 1]), demo_voter))
print("medium rank ", score_update_ranking(np.array([2, 0, 1]), np.array([0, 2, 1]), demo_voter))
print("worst rank ", score_update_ranking(np.array([1, 0, 2]), np.array([0, 2, 1]), demo_voter))