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 views29461
    Project overview1484
    Matrix views622Matrix landing page (567 views); Bat Skull Matrix (55 views);
    Media views17576Media search (1391 views); M435071 (181 views); M435131 (152 views); M435137 (151 views); M435118 (132 views); M435083 (198 views); M435129 (153 views); M435095 (167 views); M435084 (168 views); M435053 (186 views); M435086 (186 views); M435107 (145 views); M435135 (147 views); M435141 (144 views); M435127 (152 views); M435113 (147 views); M435054 (193 views); M435064 (204 views); M435146 (160 views); M435124 (180 views); M435136 (150 views); M435089 (170 views); M435076 (180 views); M435085 (206 views); M435058 (203 views); M435068 (183 views); M435057 (189 views); M435106 (156 views); M435130 (163 views); M435104 (168 views); M435087 (226 views); M435116 (143 views); M435122 (157 views); M435142 (157 views); M435088 (195 views); M435060 (187 views); M435133 (152 views); M435070 (195 views); M435072 (200 views); M435063 (158 views); M435145 (142 views); M435081 (192 views); M435069 (200 views); M435138 (158 views); M435126 (139 views); M435147 (148 views); M435056 (219 views); M435108 (153 views); M435140 (147 views); M435091 (191 views); M435062 (180 views); M435111 (150 views); M435143 (152 views); M435082 (186 views); M435094 (161 views); M435080 (171 views); M435128 (156 views); M435059 (195 views); M435066 (188 views); M435125 (141 views); M435144 (162 views); M435067 (167 views); M435114 (182 views); M435061 (206 views); M435109 (145 views); M435090 (162 views); M435134 (160 views); M435077 (162 views); M435098 (159 views); M435123 (132 views); M435100 (160 views); M435119 (145 views); M435115 (156 views); M435096 (154 views); M435078 (179 views); M435074 (165 views); M435105 (155 views); M435112 (195 views); M435097 (159 views); M435148 (158 views); M435110 (175 views); M435055 (215 views); M435099 (163 views); M435093 (185 views); M435065 (187 views); M435121 (155 views); M435073 (169 views); M435132 (149 views); M435102 (170 views); M435092 (171 views); M435075 (174 views); M435120 (156 views); M435101 (174 views); M435117 (157 views); M435079 (182 views); M435139 (140 views); M435103 (147 views);
    Taxon list3369
    Specimen list4070
    Views for media list519
    Documents list523

    Project downloads

    type number of downloads Individual items downloaded (where applicable)
    Total downloads from project152
    Project downloads139
    Matrix downloads11Bat Skull Matrix (11 downloads);
    Document downloads2Supplementary material (2 downloads);