Title: | Calculate the Knowledge-Weighted Estimate |
---|---|
Description: | According to a phenomenon known as "the wisdom of the crowds," combining point estimates from multiple judges often provides a more accurate aggregate estimate than using a point estimate from a single judge. However, if the judges use shared information in their estimates, the simple average will over-emphasize this common component at the expense of the judges’ private information. Asa Palley & Ville Satopää (2021) "Boosting the Wisdom of Crowds Within a Single Judgment Problem: Selective Averaging Based on Peer Predictions" <https://papers.ssrn.com/sol3/Papers.cfm?abstract_id=3504286> proposes a procedure for calculating a weighted average of the judges’ individual estimates such that resulting aggregate estimate appropriately combines the judges' collective information within a single estimation problem. The authors use both simulation and data from six experimental studies to illustrate that the weighting procedure outperforms existing averaging-like methods, such as the equally weighted average, trimmed average, and median. This aggregate estimate -- know as "the knowledge-weighted estimate" -- inputs a) judges' estimates of a continuous outcome (E) and b) predictions of others' average estimate of this outcome (P). In this R-package, the function knowledge_weighted_estimate(E,P) implements the knowledge-weighted estimate. Its use is illustrated with a simple stylized example and on real-world experimental data. |
Authors: | Ville Satopää [aut, cre, cph], Asa Palley [aut] |
Maintainer: | Ville Satopää <[email protected]> |
License: | GPL-2 |
Version: | 0.3.0 |
Built: | 2025-02-06 03:25:27 UTC |
Source: | https://github.com/cran/metaggR |
Palley and Satopää (2021) conducted an experiment where participants were presented with 36 different pictures of food from different restaurants and were asked to estimate the total number of calories in these dishes. Each response involves three steps:
Initial Estimates: On the first screen the participant was presented with a picture of a meal and asked How many calories do you think are in this meal?
Predictions of Others: On the second screen the participant saw the same picture, was reminded of their previous estimate, and given the statement: We will be showing this picture to other participants as well. Just as we did with you, we will ask them how many calories they believe are in this meal. The participant was then asked to predict How many calories do you think that others will guess on average?
Final Estimates: On the third screen the participant saw the same picture again and was asked After having reflected on others, what is your own final best estimate of the number of calories in this meal?
E_CALORIES_INITIAL E_CALORIES_FINAL P_CALORIES THETA_CALORIES ID_CALORIES
E_CALORIES_INITIAL E_CALORIES_FINAL P_CALORIES THETA_CALORIES ID_CALORIES
E_CALORIES_INITIAL
is a list of the judges' initial estimates of the calorie counts in each of the 36 meals.
Specifically, the th element is a vector of the judges' initial estimates of the calories in the
th meal.
E_CALORIES_FINAL
is a list of the judges' final estimates of the calorie counts in each of the 36 meals.
Specifically, the th element is a vector of the judges' final estimates of the calories in the
th meal.
P_CALORIES
is a list of the judges' predictions of others.
Specifically, the th element is a vector of the judges' predictions of other judges' average
estimate of the number of calories in the
th meal.
THETA_CALORIES
is a vector of the true calorie counts in each of the 36 meals.
Specifically, the th element is the true calorie count in the
th meal.
ID_CALORIES
is a list of the judges' identification numbers in each of the 36 meals.
Specifically, the th element is a vector of identification numbers of judges' who gave responses
for the
th meal. These values make it possible to track a judge across questions.
The elements of each list correspond to the same meal. Specifically, the th elements of
THETA_CALORIES
, E_CALORIES_INITIAL
, E_CALORIES_FINAL
, P_CALORIES
, and ID_CALORIES
represent the true calories, initial estimates, final estimates, the predictions of others, and identification
numbers of the th meal.
Asa Palley and Ville Satopää. "Boosting the Wisdom of Crowds Within a Single Judgment Problem: Selective Averaging Based on Peer Predictions." https://papers.ssrn.com/sol3/Papers.cfm?abstract_id=3504286
Palley and Soll (2019) recruited individuals on Amazon Mechanical Turk and asked them to estimate the proportion of heads in 100 flips of a biased two-sided coin. The probability of heads was unknown to the participants, who were told that it could be anywhere between 1% and 99%. Before responding, each judge was shown a sample of flips that all judges saw (shared information) and another sample of flips that was only seen by that individual or by a subset of judges (private information). Three information structures were considered:
Symmetric: All judges saw their own unique sample of flips. There are a total of 72 judgment tasks under this condition.
Nested: Some judges saw only the shared sample while others saw an additional common sample. There are a total of 24 judgment tasks under this condition.
Nested-Symmetric: Some judges saw only the shared sample while others saw their own additional sample of flips. There are a total of 24 judgment tasks under this condition.
E_COINS_SYMMETRIC E_COINS_NESTED E_COINS_NESTED_SYMMETRIC P_COINS_SYMMETRIC P_COINS_NESTED P_COINS_NESTED_SYMMETRIC THETA_COINS_SYMMETRIC THETA_COINS_NESTED THETA_COINS_NESTED_SYMMETRIC ID_COINS_SYMMETRIC ID_COINS_NESTED ID_COINS_NESTED_SYMMETRIC
E_COINS_SYMMETRIC E_COINS_NESTED E_COINS_NESTED_SYMMETRIC P_COINS_SYMMETRIC P_COINS_NESTED P_COINS_NESTED_SYMMETRIC THETA_COINS_SYMMETRIC THETA_COINS_NESTED THETA_COINS_NESTED_SYMMETRIC ID_COINS_SYMMETRIC ID_COINS_NESTED ID_COINS_NESTED_SYMMETRIC
E_COINS_SYMMETRIC
is a list of the judges' estimates of the proportion of
heads in 100 flips of a biased two-sided coin under the Symmetric condition.
Specifically, the th element is a vector of the judges' estimated proportions in the
th task.
E_COINS_NESTED
is a list of the judges' estimates of the proportion of
heads in 100 flips of a biased two-sided coin under the Nested condition.
Specifically, the th element is a vector of the judges' estimated proportions in the
th task.
E_COINS_NESTED_SYMMETRIC
is a list of the judges' estimates of the proportion of
heads in 100 flips of a biased two-sided coin under the Nested-Symmetric condition.
Specifically, the th element is a vector of the judges' estimated proportions in the
th task.
P_COINS_SYMMETRIC
is a list of the judges' predictions of other judges' average estimate
of the proportion of heads in 100 flips of a biased two-sided coin under the Symmetric condition.
Specifically, the th element is a vector of the judges' predictions of others in the
th task.
P_COINS_NESTED
is a list of the judges' predictions of other judges' average estimate
of the proportion of
heads in 100 flips of a biased two-sided coin under the Nested condition.
Specifically, the th element is a vector of the judges' predictions of others in the
th task.
P_COINS_NESTED_SYMMETRIC
is a list of the judges' predictions of other judges' average estimate
of the proportion of
heads in 100 flips of a biased two-sided coin under the Nested-Symmetric condition.
Specifically, the th element is a vector of the judges' predictions of others in the
th task.
THETA_COINS_SYMMETRIC
is a vector of the actual proportions of heads under the Symmetric condition.
Specifically, the th element is the actual proportion of heads in the
th task.
THETA_COINS_NESTED
is a vector of the actual proportions of heads under the Nested condition.
Specifically, the th element is the actual proportion of heads in the
th task.
THETA_COINS_NESTED_SYMMETRIC
is a vector of the actual proportions of heads
under the Nested-Symmetric condition.
Specifically, the th element is the actual proportion of heads in the
th task.
ID_COINS_SYMMETRIC
is a list of the judges' identification numbers in the judgment tasks
under the Symmetric condition.
Specifically, the th element is a vector of identification numbers of judges' who participated in
estimating the proportion of heads in the
th task.
These values make it possible to track a judge across judgment tasks.
ID_COINS_NESTED
is a list of the judges' identification numbers in the judgment tasks
under the Nested condition.
Specifically, the th element is a vector of identification numbers of judges' who participated in
estimating the proportion of heads in the
th task.
These values make it possible to track a judge across judgment tasks.
ID_COINS_NESTED_SYMMETRIC
is a list of the judges' identification numbers in the judgment tasks
under the Nested-Symmetric condition.
Specifically, the th element is a vector of identification numbers of judges' who participated in
estimating the proportion of heads in the
th task.
These values make it possible to track a judge across judgment tasks.
The elements of each list correspond to the same meal. For instance, the th elements of
THETA_COINS_SYMMETRIC
, E_COINS_SYMMETRIC
, P_COINS_SYMMETRIC
, and ID_COINS_SYMMETRIC
represent the true proportion, estimates, the predictions of others, and identification
numbers associated with the th task under the Symmetric condition.
Asa Palley and Jack Soll. "Extracting the Wisdom of Crowds When Information Is Shared." doi:10.1287/mnsc.2018.3047
Martinie et al. (2020) recruited individuals on Amazon Mechanical Turk and asked them to provide subjective probabilities of whether various general science statements from U.S. grade school were true or false. Problems were classified into five levels of difficulty, with level 1 being the easiest and level 5 being the most difficult. For example, one easy problem (level 1) presented the statement Omnivores only eat meat, whereas one difficult problem (level 5) presented the statement Sound waves and electromagnetic waves are examples of longitudinal waves.
The full data have been split into 5 groups based on the difficulty the questions.
E_GK_1
to E_GK_5
: A list of the judges' estimates of the probabilities
that the statements are true.
P_GK_1
to P_GK_5
: A list of the judges' predictions of others' average probability estimates.
ID_GK_1
to ID_GK_5
: A list of the judges' identification numbers.
These values make it possible to track a judge across different judgment tasks.
THETA_GK_1
to THETA_GK_5
: Actual outcomes showing whether the statements are true (1) or not (0).
The final number in the name of the data set indicates the associated difficulty level.
For instance, E_GK_5
holds the probability estimates of the most difficult questions,
THETA_GK_1
holds actual outcomes for the easiest questions, and so on.
The elements of each list correspond to the same question. For instance, the th elements
of
THETA_GK_1
, E_GK_1
, P_GK_1
, and ID_GK_1
give
the true outcome, vector of probability estimates, vector of predictions of other judges' average probability estimates,
and vector of identification numbers of the th question with difficulty level 1.
E_GK_1 E_GK_2 E_GK_3 E_GK_4 E_GK_5 P_GK_1 P_GK_2 P_GK_3 P_GK_4 P_GK_5 THETA_GK_1 THETA_GK_2 THETA_GK_3 THETA_GK_4 THETA_GK_5 ID_GK_1 ID_GK_2 ID_GK_3 ID_GK_4 ID_GK_5
E_GK_1 E_GK_2 E_GK_3 E_GK_4 E_GK_5 P_GK_1 P_GK_2 P_GK_3 P_GK_4 P_GK_5 THETA_GK_1 THETA_GK_2 THETA_GK_3 THETA_GK_4 THETA_GK_5 ID_GK_1 ID_GK_2 ID_GK_3 ID_GK_4 ID_GK_5
E_GK_1
holds judges' estimates of the outcome. Specifically, it holds a list of 100 elements,
one per general knowledge statement with difficulty level 1.
The th element is a vector of the judges' estimates of the probability that the
th statement is true.
E_GK_2
holds judges' estimates of the outcome. Specifically, it holds a list of 100 elements,
one per general knowledge statement with difficulty level 2.
The th element is a vector of the judges' estimates of the probability that the
th statement is true.
E_GK_3
holds judges' estimates of the outcome. Specifically, it holds a list of 100 elements,
one per general knowledge statement with difficulty level 3.
The th element is a vector of the judges' estimates of the probability that the
th statement is true.
E_GK_4
holds judges' estimates of the outcome. Specifically, it holds a list of 100 elements,
one per general knowledge statement with difficulty level 4.
The th element is a vector of the judges' estimates of the probability that the
th statement is true.
E_GK_5
holds judges' estimates of the outcome. Specifically, it holds a list of 100 elements,
one per general knowledge statement with difficulty level 5.
The th element is a vector of the judges' estimates of the probability that the
th statement is true.
P_GK_1
holds judges' predictions of other judges' average estimate of the outcome.
Specifically, it holds a list of 100 elements, one per general knowledge statement with difficulty level 1.
The th element is a vector of the judges' predictions of others' average estimate of the probability
that the
th statement is true.
P_GK_2
holds judges' predictions of other judges' average estimate of the outcome.
Specifically, it holds a list of 100 elements, one per general knowledge statement with difficulty level 2.
The th element is a vector of the judges' predictions of others' average estimate of the probability
that the
th statement is true.
P_GK_3
holds judges' predictions of other judges' average estimate of the outcome.
Specifically, it holds a list of 100 elements, one per general knowledge statement with difficulty level 3.
The th element is a vector of the judges' predictions of others' average estimate of the probability
that the
th statement is true.
P_GK_4
holds judges' predictions of other judges' average estimate of the outcome.
Specifically, it holds a list of 100 elements, one per general knowledge statement with difficulty level 4.
The th element is a vector of the judges' predictions of others' average estimate of the probability
that the
th statement is true.
P_GK_5
holds judges' predictions of other judges' average estimate of the outcome.
Specifically, it holds a list of 100 elements, one per general knowledge statement with difficulty level 5.
The th element is a vector of the judges' predictions of others' average estimate of the probability
that the
th statement is true.
THETA_GK_1
is a vector of 100 elements, one per general knowledge statement with difficulty level 1.
The th element shows whether the
th general statement is true (1) or false (0).
THETA_GK_2
is a vector of 100 elements, one per general knowledge statement with difficulty level 2.
The th element shows whether the
th general statement is true (1) or false (0).
THETA_GK_3
is a vector of 100 elements, one per general knowledge statement with difficulty level 3.
The th element shows whether the
th general statement is true (1) or false (0).
THETA_GK_4
is a vector of 100 elements, one per general knowledge statement with difficulty level 4.
The th element shows whether the
th general statement is true (1) or false (0).
THETA_GK_5
is a vector of 100 elements, one per general knowledge statement with difficulty level 5.
The th element shows whether the
th general statement is true (1) or false (0).
ID_GK_1
holds judges' identification numbers.
Specifically, it holds a list of 100 elements, one per general knowledge statement with difficulty level 1.
The th element is a vector of numbers identifying the judges who provides responses for the
th statement.
These values make it possible to track a judge across questions.
ID_GK_2
holds judges' identification numbers.
Specifically, it holds a list of 100 elements, one per general knowledge statement with difficulty level 2.
The th element is a vector of numbers identifying the judges who provides responses for the
th statement.
These values make it possible to track a judge across questions.
ID_GK_3
holds judges' identification numbers.
Specifically, it holds a list of 100 elements, one per general knowledge statement with difficulty level 3.
The th element is a vector of numbers identifying the judges who provides responses for the
th statement.
These values make it possible to track a judge across questions.
ID_GK_4
holds judges' identification numbers.
Specifically, it holds a list of 100 elements, one per general knowledge statement with difficulty level 4.
The th element is a vector of numbers identifying the judges who provides responses for the
th statement.
These values make it possible to track a judge across questions.
ID_GK_5
holds judges' identification numbers.
Specifically, it holds a list of 100 elements, one per general knowledge statement with difficulty level 5.
The th element is a vector of numbers identifying the judges who provides responses for the
th statement.
These values make it possible to track a judge across questions.
Marcellin Martinie, Tom Wilkening, and Piers D. L. Howe. "Using meta-predictions to identify experts in the crowd when past performance is unknown" https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0232058
This function computes and plots the influence scores described in Palley & Satopää (2021): Boosting the Wisdom of Crowds Within a Single Judgment Problem: Weighted Averaging Based on Peer Predictions. The current version of the paper is available at https://papers.ssrn.com/sol3/Papers.cfm?abstract_id=3504286
get_influence_scores(E, P, plotIt = FALSE, cutoff = 7/2)
get_influence_scores(E, P, plotIt = FALSE, cutoff = 7/2)
E |
Vector of |
P |
Vector of |
plotIt |
A boolean value. If TRUE, then the function call produces two side-by-side plots:
For more information on the plots, see the Electronic Companion of Palley & Satopää (2021): Boosting the Wisdom of Crowds Within a Single Judgment Problem: Weighted Averaging Based on Peer Predictions at https://papers.ssrn.com/sol3/Papers.cfm?abstract_id=3504286. |
cutoff |
A positive scalar describing the cutoff value for the outlier-robust knowledge-weighted estimate.
The outlier-robust version calculates the influence scores for all
judges. Each influence score is then compared against |
vector of influence scores. Intuitively, the influence score of a judge represents the amount by which the
knowledge-weighted estimate would change if that judge was removed from the crowd. Judges with an exceptionally
high influence should be inspected. As a default cutoff value, the authors recommend
times the interquartile range
of the individual judges' influence scores.
# Illustration on the Three Gorges Dam Example in Palley & Satopää (2021): # The original example with 6 judges is augmented with a 7th judge with an extreme response. # Judges' estimates: E2 = c(50, 134, 206, 290, 326, 374, 1000) # Judges' predictions of others P2 = c(26, 92, 116, 218, 218, 206, 400) # The influence score of the 7th judge is much higher than the other judges' scores. # This judge's response should be inspected and potentially excluded from # the final knowledge-weighted estimate. get_influence_scores(E2,P2)
# Illustration on the Three Gorges Dam Example in Palley & Satopää (2021): # The original example with 6 judges is augmented with a 7th judge with an extreme response. # Judges' estimates: E2 = c(50, 134, 206, 290, 326, 374, 1000) # Judges' predictions of others P2 = c(26, 92, 116, 218, 218, 206, 400) # The influence score of the 7th judge is much higher than the other judges' scores. # This judge's response should be inspected and potentially excluded from # the final knowledge-weighted estimate. get_influence_scores(E2,P2)
Palley and Soll (2019) recruited volunteers passing through the student union to estimate the total price of 10 different bundles of nonperishable grocery items. Examples of items include a bottle of 190 Lil Critters Gummy Vites Sour Complete multivitamins ($10.93), a 5-oz. can of Wild Planet wild albacore tuna in extra virgin olive oil ($4.19), and an 11 oz. bag of Stauffer's Animal Crackers ($1.00).
E_GROCERIES P_GROCERIES THETA_GROCERIES ID_GROCERIES
E_GROCERIES P_GROCERIES THETA_GROCERIES ID_GROCERIES
E_GROCERIES
is a list of the judges' estimates of the prices in each of the 10 bundles of groceries.
Specifically, the th element is a vector of the judges' estimates of the price of the
th bundle.
P_GROCERIES
is a list of the judges' predictions of others.
Specifically, the th element is a vector of the judges' predictions of other judges' average
estimate of the price of the
th bundle.
THETA_GROCERIES
is a vector of the prices of the 10 bundles of groceries.
Specifically, the th element is the actual price of the
th bundle.
ID_GROCERIES
is a list of the judges' identification numbers in the judgment tasks.
Specifically, the th element is a vector of identification numbers of judges' who participated in
estimating the price of the
th bundle. These values make it possible to track a judge across judgment tasks.
The elements of each list correspond to the same judgment task. Specifically, the th elements of
THETA_GROCERIES
, E_GROCERIES
, P_GROCERIES
, and ID_GROCERIES
represent the true price, estimates, the predictions of others, and identification
numbers associated with the th bundle.
Asa Palley and Jack Soll. "Extracting the Wisdom of Crowds When Information Is Shared." doi:10.1287/mnsc.2018.3047
This function computes the knowledge gap described in Palley & Satopää (2021): Boosting the Wisdom of Crowds Within a Single Judgment Problem: Weighted Averaging Based on Peer Predictions. The current version of the paper is available at https://papers.ssrn.com/sol3/Papers.cfm?abstract_id=3504286
knowledge_gap(E, P, alpha)
knowledge_gap(E, P, alpha)
E |
Vector of |
P |
Vector of |
alpha |
Vector of |
A singular value representing the knowledge gap. This represents the expected distance between the
weighted combination of the judges' estimates,
where the weights have been given by alpha
, and the optimal aggregate estimate called the Global Posterior Expectation (GPE).
# Illustration on the Three Gorges Dam Example in Palley & Satopää (2021): # Judges' estimates: E = c(50, 134, 206, 290, 326, 374) # Judges' predictions of others P = c(26, 92, 116, 218, 218, 206) # First find the knowledge-weights that minimize the knowledge gap: alpha = knowledge_weights(E,P) knowledge_gap(E,P, alpha) # Small perturbations increase the knowledge gap: alpha_per = alpha alpha_per[1] = alpha_per[1] + 0.001 alpha_per[2] = alpha_per[2] - 0.001 knowledge_gap(E,P, alpha_per)
# Illustration on the Three Gorges Dam Example in Palley & Satopää (2021): # Judges' estimates: E = c(50, 134, 206, 290, 326, 374) # Judges' predictions of others P = c(26, 92, 116, 218, 218, 206) # First find the knowledge-weights that minimize the knowledge gap: alpha = knowledge_weights(E,P) knowledge_gap(E,P, alpha) # Small perturbations increase the knowledge gap: alpha_per = alpha alpha_per[1] = alpha_per[1] + 0.001 alpha_per[2] = alpha_per[2] - 0.001 knowledge_gap(E,P, alpha_per)
This function computes the knowledge-weighted estimate from Palley & Satopää (2021): Boosting the Wisdom of Crowds Within a Single Judgment Problem: Weighted Averaging Based on Peer Predictions. The current version of the paper is available at https://papers.ssrn.com/sol3/Papers.cfm?abstract_id=3504286.
knowledge_weighted_estimate( E, P, cutoff = 7/2, remove_inf = FALSE, no_inf_check = FALSE )
knowledge_weighted_estimate( E, P, cutoff = 7/2, remove_inf = FALSE, no_inf_check = FALSE )
E |
Vector of |
P |
Vector of |
cutoff |
A positive scalar describing the cutoff value for the outlier-robust knowledge-weighted estimate.
The outlier-robust version calculates the influence scores for all
judges (see |
remove_inf |
A boolean value. If TRUE, then all exceptionally influential judges are removed before
the knowledge-weighted estimate is calculated. If FALSE, then the knowledge-weighted estimate is
calculated based on the responses of all |
no_inf_check |
A boolean value. If TRUE, then the influence scores are not calculated at any point. This can be helpful to speed up calculations. However, the authors recommend checking for influential judges each time the knowledge weighted estimate is applied. |
A singular value representing the knowledge-weighted estimate
# Illustration on the Three Gorges Dam Example in Palley & Satopää (2021): # Judges' estimates: E1 = c(50, 134, 206, 290, 326, 374) # Judges' predictions of others P1 = c(26, 92, 116, 218, 218, 206) # Knowledge-weighted estimate is 329.305 knowledge_weighted_estimate(E1,P1) # The original example with 6 judges is augmented with a 7th judge with an extreme response. # Judges' estimates: E2 = c(50, 134, 206, 290, 326, 374, 1000) # Judges' predictions of others P2 = c(26, 92, 116, 218, 218, 206, 400) # Knowledge-weighted estimate is 630.0491 # The function call warns of exceptionally influential judges. knowledge_weighted_estimate(E2,P2) # Calculate the knowledge-weighted estimate without influence score checking. knowledge_weighted_estimate(E2,P2, no_inf_check = TRUE) # Calculate the influence scores of the judges. # This reveals that the 7th judge is highly influential. get_influence_scores(E2,P2) # Calculate the outlier-robust knowledge-weighted estimate. # This removes all highly influential judges, namely judge 7 in this simple example, # and returns the knowledge-weighted estimate of the remaining judges' estimates. # This estimate aligns with the original 329.305 knowledge_weighted_estimate(E2,P2, remove_inf = TRUE)
# Illustration on the Three Gorges Dam Example in Palley & Satopää (2021): # Judges' estimates: E1 = c(50, 134, 206, 290, 326, 374) # Judges' predictions of others P1 = c(26, 92, 116, 218, 218, 206) # Knowledge-weighted estimate is 329.305 knowledge_weighted_estimate(E1,P1) # The original example with 6 judges is augmented with a 7th judge with an extreme response. # Judges' estimates: E2 = c(50, 134, 206, 290, 326, 374, 1000) # Judges' predictions of others P2 = c(26, 92, 116, 218, 218, 206, 400) # Knowledge-weighted estimate is 630.0491 # The function call warns of exceptionally influential judges. knowledge_weighted_estimate(E2,P2) # Calculate the knowledge-weighted estimate without influence score checking. knowledge_weighted_estimate(E2,P2, no_inf_check = TRUE) # Calculate the influence scores of the judges. # This reveals that the 7th judge is highly influential. get_influence_scores(E2,P2) # Calculate the outlier-robust knowledge-weighted estimate. # This removes all highly influential judges, namely judge 7 in this simple example, # and returns the knowledge-weighted estimate of the remaining judges' estimates. # This estimate aligns with the original 329.305 knowledge_weighted_estimate(E2,P2, remove_inf = TRUE)
This function computes the weighted used in the knowledge-weighted estimate of Palley & Satopää (2021): Boosting the Wisdom of Crowds Within a Single Judgment Problem: Weighted Averaging Based on Peer Predictions. The current version of the paper is available at https://papers.ssrn.com/sol3/Papers.cfm?abstract_id=3504286
knowledge_weights(E, P)
knowledge_weights(E, P)
E |
Vector of |
P |
Vector of |
vector of weights that minimizes the knowledge gap and lead to the knowledge-weighted estimate.
# Illustration on the Three Gorges Dam Example in Palley & Satopää (2021): # Judges' estimates: E = c(50, 134, 206, 290, 326, 374) # Judges' predictions of others P = c(26, 92, 116, 218, 218, 206) # Weights used in the knowledge-weighted estimate: alpha = knowledge_weights(E,P) # Knowledge-weighted estimate is 329.3266 t(alpha) %*% E # Alternatively, the knowledge-weighted estimate can be calculated using # the knowledge_weighted_estimate() function. This returns 329.305, which # is slightly different from the above result. The difference arises because # knowledge_weighted_estimate() improves stability by standardizing the # judges' responses before aggregating them. knowledge_weighted_estimate(E,P)
# Illustration on the Three Gorges Dam Example in Palley & Satopää (2021): # Judges' estimates: E = c(50, 134, 206, 290, 326, 374) # Judges' predictions of others P = c(26, 92, 116, 218, 218, 206) # Weights used in the knowledge-weighted estimate: alpha = knowledge_weights(E,P) # Knowledge-weighted estimate is 329.3266 t(alpha) %*% E # Alternatively, the knowledge-weighted estimate can be calculated using # the knowledge_weighted_estimate() function. This returns 329.305, which # is slightly different from the above result. The difference arises because # knowledge_weighted_estimate() improves stability by standardizing the # judges' responses before aggregating them. knowledge_weighted_estimate(E,P)
Palley and Soll (2019) recruited participants through ClearVoice Research and Amazon Mechanical Turk to estimate the probability that one team or the other would win various games in the 2014, 2015, and 2016 NCAA Division I Men’s Basketball Tournaments. The responses for the Round of 64 games and Round of 16 games are treated separately because the Round of 64 games happen at the start of the tournament and often involve heavily mismatched teams (e.g., a 1 seed versus a 16 seed) while Round of 16 games typically involve more evenly matched teams, with implied betting market probabilities closer to 50%.
E_NCAA_R64 E_NCAA_R16 P_NCAA_R64 P_NCAA_R16 THETA_NCAA_R64 THETA_NCAA_R16 ID_NCAA_R64 ID_NCAA_R16
E_NCAA_R64 E_NCAA_R16 P_NCAA_R64 P_NCAA_R16 THETA_NCAA_R64 THETA_NCAA_R16 ID_NCAA_R64 ID_NCAA_R16
E_NCAA_R64
is a list of the judges' estimates of the probability that
the given team wins in Round of 64.
Specifically, the th element is a vector of the judges' estimated probability in the
th game.
E_NCAA_R16
is a list of the judges' estimates of the probability that
the given team wins in Round of 16.
Specifically, the th element is a vector of the judges' estimated probability in the
th game.
P_NCAA_R64
is a list of the judges' predictions of other judges' average probability that
the given team wins in Round of 64.
Specifically, the th element is a vector of the judges' predictions of the other judges' average probabilities in the
th game.
P_NCAA_R16
is a list of the judges' predictions of other judges' average probability that
the given team wins in Round of 16.
Specifically, the th element is a vector of the judges' predictions of the other judges' average probabilities in the
th game.
THETA_NCAA_R64
is a vector of the actual outcomes of the games in the Round of 64.
Specifically, the th element is the actual outcome of
th game in Round of 64.
THETA_NCAA_R16
is a vector of the actual outcomes of the games in the Round of 16.
Specifically, the th element is the actual outcome of
th game in Round of 16.
ID_NCAA_R64
is a list of the judges' identification numbers in the judgment tasks
associated with the Round of 64 games.
Specifically, the th element is a vector of identification numbers of judges' who participated in
estimating the probability of a given team winning the
th game of Round of 64.
These values make it possible to track a judge across judgment tasks.
ID_NCAA_R16
is a list of the judges' identification numbers in the judgment tasks
associated with the Round of 16 games.
Specifically, the th element is a vector of identification numbers of judges' who participated in
estimating the probability of a given team winning the
th game of Round of 16.
These values make it possible to track a judge across judgment tasks.
The elements of each list correspond to the same game. Specifically, the th elements of
THETA_NCAA_R16
, E_NCAA_R16
, P_NCAA_R16
, and ID_NCAA_R16
represent the true outcome, estimates, the predictions of others, and identification
numbers associated with the th game in the Round of 16.
Asa Palley and Jack Soll. "Extracting the Wisdom of Crowds When Information Is Shared." doi:10.1287/mnsc.2018.3047