Smartphone citizen science: Can a conservation hypothesis be tested using non specialist technology?

Abstract

The work presented here, describes a citizen science scoping study using accessible stand-alone smartphone technology. Paper discolouration in a single journal type, the Wagga Wagga Daily Advertiser published from the dates 1876-2004 was chosen as the focus of study, with a specific hypothesis to be tested; that the wartime journals were more discoloured by yellowing due to them being accessed more frequently. A series of measurements were carried out with a smartphone device using the camera to act as a colorimeter and converting the CIE L xy vector length into a yellowing parameter Y. A number of preliminary attempts were made to recreate conditions that corresponded to the measurements of Y using a conventional spectrophotometer, this was by standardising distance from object and through a number of lighting conditions. It was found that the most consistently comparable results (with an offset) could be obtained using an iPhone 6S with the light source from an additional iPhone with sample to aperture distance of 4 cm. Both studies showed that the large increase in Y occurred in journals printed around 1912 with a plateau of elevated Y value detected in journals until the 1950s after which the Y parameter decreased until 2004. This indicates the frequency access hypothesis to be false and this negative proof was able to be evidenced by the data collected by the iPhone. It would be suggested that great care needs to be taken if such an approach of stand-alone measurement were to be taken into citizen science; training and testing would need to be undertaken, because of the challenge of reproducibility and the risk of sampling irreplaceable objects.