Was Charles Darwin a citizen scientist, when boarding, as a yet untrained naturalist, the HMS Beagle to make observations that later revolutionized our knowledge of life on earth? Already centuries ago ordinary people (but mostly wealthy gentlemen) recorded features and observations of the natural world. With more structured designs and the inclusion of the broader public, a field now commonly known as citizen science has developed. It has been increasingly transformed in recent decades with more and more options to generate, discover and share records of natural observations.

Today, an increasing number of citizen science projects and participating citizens exists. The projects are either based on systematic- or mass participation. They vary in degree of participation (contributory, collaborative, and co-created) as well as geographical scales, from local water quality measurements to revealing continental migratory patterns in bird populations. A participating public is vital to advancements in numerous research fields. Although most citizen scientists don’t define themselves by some potential scientific output that any of their observations may contribute to, as professional scientists we should not only acknowledge the input of the general public into our work but make the gained knowledge more accessible to further stimulate public engagement.

The reasons for participating are different for each individual and range from naturalists simply following their passion to people longing to engage in a community or compete with fellow enthusiasts. Consequently, very different types of citizen science data are generated continuously that all need different treatments before further use. In the next blog post we’ll scratch the surface of different statistical approaches to tackle the bias-diversity of citizen science data.