Project 2577: M. A. O’Leary, K. Alphonse, A. H. Mariangeles, D. Cavaliere, A. Cirranello, T. G. Dietterich, M. Julius, S. Kaufman, E. Law, M. Passarotti, A. Reft, J. Robalino, N. B. Simmons, S. Y. Smith, D. W. Stevenson, E. Theriot, P. M. Velazco, R. L. Walls, M. Yu, M. Daly. 2018. Crowds Replicate Performance of Scientific Experts Scoring Phylogenetic Matrices of Phenotypes. Systematic Biology. 67 (1):49-60.
Specimen: Kerivoula hardwickii (AMNH/Mammalogy:107483)
View: Skull-dorsal


Scientists building the Tree of Life face an overwhelming challenge to categorize phenotypes (e.g., anatomy, physiology) from millions of living and fossil species. This biodiversity challenge far outstrips the capacities of trained scientific experts. Here we explore whether crowdsourcing can be used to collect matrix data on a large scale with the participation of the non-expert students, or “citizen scientists.” Crowdsourcing, or data collection by non-experts, frequently via the internet, has enabled scientists to tackle some large-scale data collection challenges too massive for individuals or scientific teams alone. The quality of work by non-expert crowds is, however, often questioned and little data has been collected on how such crowds perform on complex tasks such as phylogenetic character coding. We studied a crowd of over 600 non-experts, and found that they could use images to identify anatomical similarity (hypotheses of homology) with an average accuracy of 82% compared to scores provided by experts in the field. This performance pattern held across the Tree of Life, from protists to vertebrates. We introduce a procedure that predicts the difficulty of each character and that can be used to assign harder characters to experts and easier characters to a non-expert crowd for scoring. We test this procedure in a controlled experiment comparing crowd scores to those of experts and show that crowds can produce matrices with over 90% of cells scored correctly while reducing the number of cells to be scored by experts by 50%. Preparation time, including image collection and processing, for a crowdsourcing experiment is significant, and does not currently save time of scientific experts overall. However, if innovations in automation or robotics can reduce such effort, then large-scale implementation of our method could greatly increase the collective scientific knowledge of species phenotypes for phylogenetic tree building. For the field of crowdsourcing, we provide a rare study with ground truth, or an experimental control that many studies lack, and contribute new methods on how to coordinate the work of experts and non-experts. We show that there are important instances in which crowd consensus is not a good proxy for correctness.

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Article DOI: 10.1093/sysbio/syx052

Project DOI: 10.7934/P2577,
This project containsMatrices
  • 96 Media
  • 1 Matrix
  • 1 Document
  • 6 Taxa
  • 15 Specimens
  • 20 Characters
Total size of project's media files: 297.77M

Download Project SDD File
Total scored cells: 140
Total media associated with cells: 122
Total labels associated with cell media: 148
Total characters: 20
Total characters with associated media: 20
Total characters with media with labels: 0
Total character states: 55
Total character states with associated media: 52
Total character states with media with labels:0
Total unordered/ordered characters:20/0
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MorphoBank Project 2577

    This research
    supported by

    Authors' Institutions

    • Ohio State University

    • Oregon State University

    • University of Arizona

    • University of Michigan

    • University of Texas at Austin

    • University of Waterloo

    • American Museum of Natural History

    • Drexel University

    • Kenx Technology Inc

    • New York Botanical Garden

    • St. Cloud State University

    • Stony Brook University

    • Whirl-i-gig

    • College of William and Mary

    • Howard Hughes Medical Institute


    member name taxa specimens media chars character
    cell scorings
    (scored, NPA, "-")
    Andrea Cirranello
    Project Administrator
    Last logged in 05/30/17
    (0, 0, 0)
    Maureen O'Leary
    Full membership
    Last logged in Never
    (0, 0, 0)
    Nancy Simmons
    Full membership
    Last logged in Never
    (0, 0, 0)
    Paul Velazco
    Full membership
    Last logged in Never
    (0, 0, 0)

    Taxonomic Overview for Matrix 'M24371' (6 Taxa)

    taxon unscored
    no cell
    "-" cellscell images labels on
    cell images
    [1] Cynopterus sphinx
    Last Modified in 12/21/16
    [2] Saccopteryx bilineata
    Last Modified in 12/21/16
    [3] Trachops cirrhosus
    Last Modified in 12/21/16
    [4] Kerivoula hardwickii
    Last Modified in 12/21/16
    [5] Miniopterus schrebersii
    Last Modified in 12/21/16
    [6] Erinaceus europaeus
    Last Modified in 12/21/16

    Project views

    type number of views Individual items viewed (where applicable)
    Total project views25995
    Project overview1372
    Matrix views555Matrix landing page (507 views); Bat Skull Matrix (48 views);
    Media views15391Media search (1206 views); M435071 (159 views); M435131 (133 views); M435137 (135 views); M435118 (114 views); M435083 (173 views); M435129 (135 views); M435095 (149 views); M435084 (144 views); M435053 (161 views); M435086 (161 views); M435107 (129 views); M435135 (130 views); M435141 (127 views); M435127 (134 views); M435113 (129 views); M435054 (169 views); M435064 (178 views); M435146 (144 views); M435124 (161 views); M435136 (132 views); M435089 (144 views); M435076 (157 views); M435085 (183 views); M435058 (178 views); M435068 (160 views); M435057 (165 views); M435106 (139 views); M435130 (146 views); M435104 (149 views); M435087 (203 views); M435116 (125 views); M435122 (137 views); M435142 (137 views); M435088 (170 views); M435060 (162 views); M435133 (134 views); M435070 (170 views); M435072 (176 views); M435063 (134 views); M435145 (124 views); M435081 (167 views); M435069 (175 views); M435138 (140 views); M435126 (118 views); M435147 (133 views); M435056 (193 views); M435108 (134 views); M435140 (129 views); M435091 (167 views); M435062 (158 views); M435111 (133 views); M435143 (137 views); M435082 (161 views); M435094 (142 views); M435080 (145 views); M435128 (135 views); M435059 (168 views); M435066 (164 views); M435125 (125 views); M435144 (145 views); M435067 (142 views); M435114 (164 views); M435061 (180 views); M435109 (128 views); M435090 (139 views); M435134 (142 views); M435077 (136 views); M435098 (140 views); M435123 (115 views); M435100 (143 views); M435119 (124 views); M435115 (138 views); M435096 (135 views); M435078 (154 views); M435074 (140 views); M435105 (138 views); M435112 (176 views); M435097 (140 views); M435148 (139 views); M435110 (158 views); M435055 (187 views); M435099 (139 views); M435093 (158 views); M435065 (163 views); M435121 (138 views); M435073 (145 views); M435132 (130 views); M435102 (153 views); M435092 (149 views); M435075 (152 views); M435120 (138 views); M435101 (159 views); M435117 (139 views); M435079 (156 views); M435139 (123 views); M435103 (126 views);
    Taxon list3069
    Specimen list3539
    Views for media list459
    Documents list475

    Project downloads

    type number of downloads Individual items downloaded (where applicable)
    Total downloads from project126
    Project downloads113
    Matrix downloads11Bat Skull Matrix (11 downloads);
    Document downloads2Supplementary material (2 downloads);