Overt Political Signalling Undermines Collective Intelligence in Community-Based Content Moderation

Dataset 1: inds_evals.csv This dataset contains data from the individual note-writing phase of the study. Each row represents data from one pair of participants who were later grouped together for the collaborative note-writing task. The dataset includes both the notes written by participants during the individual phase and the corresponding evaluations of those notes. Each column is described in detail below. Variable Type Explanation group_id int Unique identifier for each group. pa_code string Unique ID assigned to participant A. pb_code string Unique ID assigned to participant B. pa_politics string Self-reported partisanship of participant A (Democrat or Republican). pb_politics string Self-reported partisanship of participant B (Democrat or Republican). pa_politics_score int Political partisanship score of participant A on a 10-point scale from strongly Democrat to strongly Republican (1–4 = Democrat, 5 = Neutral, 6–10 = Republican). pb_politics_score int Political partisanship score of participant B on a 10-point scale from strongly Democrat to strongly Republican (1–4 = Democrat, 5 = Neutral, 6–10 = Republican). group_treatment string Group composition (RR = two Republicans, DD = two Democrats, DR = one Democrat and one Republican). tag_a string Tag assigned to the post by participant A (not_misleading, somewhat_misleading, misleading). tag_b string Tag assigned to the post by participant B (not_misleading, somewhat_misleading, misleading). note_a string Note written by participant A during the individual task. note_b string Note written by participant B during the individual task. image string Unique ID corresponding to the post shown to the participants. The ID (with a .png extension) can be used to locate the post on x.com. links_a int Number of hyperlinks included in participant A’s note. links_b int Number of hyperlinks included in participant B’s note. length_a int Length of participant A’s note in words. length_b int Length of participant B’s note in words. std_level_a int Sophistication score of participant A’s note (see Supplementary Information for details). std_level_b int Sophistication score of participant B’s note (see Supplementary Information for details). stats_a int Indicator for whether participant A’s note contains a number (0 = No, 1 = Yes). stats_b int Indicator for whether participant B’s note contains a number (0 = No, 1 = Yes). image_type string Partisanship of the post: D = Democratic ideology, R = Republican ideology. note_id_a int Unique ID assigned to participant A’s note. note_id_b int Unique ID assigned to participant B’s note. d_helpfulness_a float Helpfulness score given to participant A’s note by Democratic evaluators (see Materials and Methods). d_context_a float Context score given to participant A’s note by Democratic evaluators (see Supplementary Information for details). d_fairness_a float Fairness score given to participant A’s note by Democratic evaluators (see Supplementary Information for details). d_relevance_a float Relevance score given to participant A’s note by Democratic evaluators (see Supplementary Information for details). d_readability_a float Readability score given to participant A’s note by Democratic evaluators (see Supplementary Information for details). d_sources_a float Source quality score for participant A’s note given by Democratic evaluators (see Supplementary Information for details). r_helpfulness_a float Helpfulness score given to participant A’s note by Republican evaluators (see Materials and Methods). r_context_a float Context score given to participant A’s note by Republican evaluators (see Supplementary Information for details). r_fairness_a float Fairness score given to participant A’s note by Republican evaluators (see Supplementary Information for details). r_relevance_a float Relevance score given to participant A’s note by Republican evaluators (see Supplementary Information for details). r_readability_a float Readability score given to participant A’s note by Republican evaluators (see Supplementary Information for details). r_sources_a float Source quality score for participant A’s note given by Republican evaluators (see Supplementary Information for details). d_helpfulness_b float Helpfulness score given to participant B’s note by Democratic evaluators (see Materials and Methods). d_context_b float Context score given to participant B’s note by Democratic evaluators (see Supplementary Information for details). d_fairness_b float Fairness score given to participant B’s note by Democratic evaluators (see Supplementary Information for details). d_relevance_b float Relevance score given to participant B’s note by Democratic evaluators (see Supplementary Information for details). d_readability_b float Readability score given to participant B’s note by Democratic evaluators (see Supplementary Information for details). d_sources_b float Source quality score for participant B’s note given by Democratic evaluators (see Supplementary Information for details). r_helpfulness_b float Helpfulness score given to participant B’s note by Republican evaluators (see Materials and Methods). r_context_b float Context score given to participant B’s note by Republican evaluators (see Supplementary Information for details). r_fairness_b float Fairness score given to participant B’s note by Republican evaluators (see Supplementary Information for details). r_relevance_b float Relevance score given to participant B’s note by Republican evaluators (see Supplementary Information for details). r_readability_b float Readability score given to participant B’s note by Republican evaluators (see Supplementary Information for details). r_sources_b float Source quality score for participant B’s note given by Republican evaluators (see Supplementary Information for details). expert_helpfulness_a float Helpfulness score given to participant A’s note by expert evaluators (see Materials and Methods). expert_helpfulness_b float Helpfulness score given to participant B’s note by expert evaluators (see Materials and Methods). Dataset 2: gp_evals.csv This dataset contains data from the collaborative note-writing phase of the study. Each row represents data from one pair of participants who were grouped together to write a note collaboratively. The dataset includes both the collaboratively written notes and their corresponding evaluations. Each column is described in detail below. Variable Type Explanation group_id int Unique identifier for each group. pa_code string Unique ID assigned to participant A. pb_code string Unique ID assigned to participant B. pa_politics string Self-reported partisanship of participant A (Democrat or Republican). pb_politics string Self-reported partisanship of participant B (Democrat or Republican). pa_politics_score int Political ideology score of participant A on a 10-point scale from strongly Democrat to strongly Republican (1–4 = Democrat, 5 = Neutral, 6–10 = Republican). pb_politics_score int Political ideology score of participant B on a 10-point scale from strongly Democrat to strongly Republican (1–4 = Democrat, 5 = Neutral, 6–10 = Republican). group_treatment string Group composition (RR = two Republicans, DD = two Democrats, DR = one Democrat and one Republican). tag_a string Tag assigned to the post by participant A (not_misleading, somewhat_misleading, misleading). tag_b string Tag assigned to the post by participant B (not_misleading, somewhat_misleading, misleading). note_a string Note written by participant A during the collaborative task. note_b string Note written by participant B during the collaborative task. image string Unique ID corresponding to the post shown to the participants. The ID (with a .png extension) can be used to locate the post on x.com. session_tag boolean Indicates whether the group was in the covert or overt treatment (TRUE = overt, FALSE = covert). See Materials and Methods for details. pa_eval int Score given by participant A indicating how easy they found the collaboration. See Supplementary Information for details. pb_eval int Score given by participant B indicating how easy they found the collaboration. See Supplementary Information for details. pa_chat list of strings Messages sent by participant A. pb_chat list of strings Messages sent by participant B. similar boolean Indicates whether the participants in the group uploaded similar notes. links_a int Number of hyperlinks included in participant A’s note. links_b int Number of hyperlinks included in participant B’s note. length_a int Length of participant A’s note in words. length_b int Length of participant B’s note in words. std_level_a int Sophistication score of participant A’s note (see Supplementary Information for details). std_level_b int Sophistication score of participant B’s note (see Supplementary Information for details). stats_a int Indicator for whether participant A’s note contains a number (0 = No, 1 = Yes). stats_b int Indicator for whether participant B’s note contains a number (0 = No, 1 = Yes). image_type string Partisanship of the post: D = Democratic ideology, R = Republican ideology. note_id_a int Unique ID assigned to participant A’s note. note_id_b int Unique ID assigned to participant B’s note. d_helpfulness_a float Helpfulness score given to participant A’s note by Democratic evaluators (see Materials and Methods). d_context_a float Context score given to participant A’s note by Democratic evaluators (see Supplementary Information for details). d_fairness_a float Fairness score given to participant A’s note by Democratic evaluators (see Supplementary Information for details). d_relevance_a float Relevance score given to participant A’s note by Democratic evaluators (see Supplementary Information for details). d_readability_a float Readability score given to participant A’s note by Democratic evaluators (see Supplementary Information for details). d_sources_a float Source quality score for participant A’s note given by Democratic evaluators (see Supplementary Information for details). r_helpfulness_a float Helpfulness score given to participant A’s note by Republican evaluators (see Materials and Methods). r_context_a float Context score given to participant A’s note by Republican evaluators (see Supplementary Information for details). r_fairness_a float Fairness score given to participant A’s note by Republican evaluators (see Supplementary Information for details). r_relevance_a float Relevance score given to participant A’s note by Republican evaluators (see Supplementary Information for details). r_readability_a float Readability score given to participant A’s note by Republican evaluators (see Supplementary Information for details). r_sources_a float Source quality score for participant A’s note given by Republican evaluators (see Supplementary Information for details). d_helpfulness_b float Helpfulness score given to participant B’s note by Democratic evaluators (see Materials and Methods). d_context_b float Context score given to participant B’s note by Democratic evaluators (see Supplementary Information for details). d_fairness_b float Fairness score given to participant B’s note by Democratic evaluators (see Supplementary Information for details). d_relevance_b float Relevance score given to participant B’s note by Democratic evaluators (see Supplementary Information for details). d_readability_b float Readability score given to participant B’s note by Democratic evaluators (see Supplementary Information for details). d_sources_b float Source quality score for participant B’s note given by Democratic evaluators (see Supplementary Information for details). r_helpfulness_b float Helpfulness score given to participant B’s note by Republican evaluators (see Materials and Methods). r_context_b float Context score given to participant B’s note by Republican evaluators (see Supplementary Information for details). r_fairness_b float Fairness score given to participant B’s note by Republican evaluators (see Supplementary Information for details). r_relevance_b float Relevance score given to participant B’s note by Republican evaluators (see Supplementary Information for details). r_readability_b float Readability score given to participant B’s note by Republican evaluators (see Supplementary Information for details). r_sources_b float Source quality score for participant B’s note given by Republican evaluators (see Supplementary Information for details). expert_helpfulness_a float Helpfulness score given to participant A’s note by expert evaluators (see Materials and Methods). expert_helpfulness_b float Helpfulness score given to participant B’s note by expert evaluators (see Materials and Methods).