{"id":1593,"date":"2018-12-13T09:40:10","date_gmt":"2018-12-13T08:40:10","guid":{"rendered":"http:\/\/blog.creamontblanc.org?p=1593"},"modified":"2018-12-13T09:40:25","modified_gmt":"2018-12-13T08:40:25","slug":"do-you-see-what-i-see-interobserver-variability-in-citizen-science","status":"publish","type":"post","link":"https:\/\/blog.creamontblanc.org?p=1535","title":{"rendered":"Do you see what I see? Interobserver variability in citizen science"},"content":{"rendered":"

Participants in CREA Mont-Blanc\u2019s citizen science program Ph\u00e9noclim make repeat observations of tree phenology. To help us study whether or not our data is reliable, it is useful to know if two volunteer observers independently make the same evaluation of the same tree.\u00a0 Here are the results and lessons learned from the experiment we carried out with students from\u00a0Franklin University Switzerland<\/a> this fall.<\/strong><\/p>\n

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Students from Franklin University Switzerland observing the phenology of larch trees \u00a9 CREA Mont-Blanc<\/em><\/strong><\/p>\n

Ph\u00e9noclim and the differences between observers<\/h2>\n

In the citizen science program, Ph\u00e9noclim<\/a>, volunteer observers participate in monitoring plant phenology to help our understanding of the impacts of climate change on living things.\u00a0 The phenological event observed depends on the season, and in the fall, Phenoclim focuses on color change in leaves and needles.\u00a0 Over the course of the season, volunteers observe different tree species including birch, beech, mountain-ash and larch, recording the date when 10% and 50% of leaves or needles change color.<\/p>\n

Making these observations is not as easy as it might seem, and a few key questions have arisen: is there consistency among observations made by different observers? When looking at the same tree, do volunteers note the same percentage of color change?<\/p>\n

The protocol<\/h2>\n

To help us answer these questions, 20 students from Franklin University Switzerland headed out into the field in Vallorcine (1300 meters) and Loriaz (1900 meters) with the CREA Mont-Blanc team.\u00a0 In each of the study areas, 30 larch trees had been pre-identified.\u00a0 Students visited the two study areas and evaluated the percentage of color change in each of the 30 trees.<\/p>\n

Results of their observations:<\/h2>\n

The interactive graphic below presents the results of the observations made by the students.\u00a0 Each point represents a single student\u2019s observation of an individual tree.\u00a0 The observations from Vallorcine (1300 meters) appear in blue, while the observations made at Loriaz (1900 meters) appear in red.<\/p>\n

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