Since the 1960’s, public assessments of landscapes have often been carried out using photographic representations. How reliable and valid are these assessments compared with on-site observations? In the present study, participants have been asked to judge different areas in terms of a limited feature: the biodiversity of the area.

Digitalized photos from six different study areas were made available on the Internet, along with a questionnaire consisting of a semantic form with specific words/expressions to be rated in relation to the photos (four per area). Participants were recruited via mailing lists and informal contacts. These results were compared with a study in which students and ecologists had rated the same places using the same form, but this time on-site. The Internet participants were also asked to state their profession/education to make comparisons possible. The comparisons revealed differences between on-site and photo-based ratings, but the main difference was expressed by on-site biologists regarding areas with the highest experienced biodiversity values, possibly due to their higher degree of expertise and use of more senses than can be used when judging photographs. Concerning laymen in particular, it is concluded that the comparison between on-site and photo-based ratings is not conclusive enough to allow us to determine whether it is appropriate to use one method as a substitute for the other.