“…The problems associated with the involvement of volunteers of mixed background in data generation are becoming increasingly well known (Dennis & Hardy, ; Dennis et al ., ; Boakes et al ., ; Hochachka et al ., ), as are the solutions for dealing with them (e.g. Kremen et al ., ; Snäll et al ., , ; Breed et al ., ; Dennis et al ., ; Zbinden et al ., ; Thomas et al ., ). Overall, using information generated by mixed volunteers requires a good understanding of what potential biases and noise may be generated by the sampling process (Dennis & Thomas, ; Isaac & Pocock, ).…”