8   3 A study was conducted into whether social media data could be used to understand tourists’ preferences for nature-based experiences. A large number of photographs taken by tourists at Kruger National Park over a given period, and then posted on Instagram and Flickr, was analysed. The researchers divided the photographs into categories according to subject matter. They then used two-sample z-tests to compare proportions of pictures posted on Instagram with those posted on Flickr, for each category. The p-values from some of these tests are given in Figure 1. All differences were calculated as (proportion on Instagram) – (proportion on Flickr). Category p-value People active p < 0.0001 People posing p < 0.01 Birds p < 0.01 Arthropods (insects, spiders, etc.) p < 0.01 Reptiles p < 0.01 Figure 1 [Data source: https://conbio.onlinelibrary.wiley.com/doi/pdf/10.1111/conl.12343] (a) Interpret, in context, the p-value in Figure 1 for ‘People active’. (2) _____________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________ Turn over 9   Question 3 continued The researchers also calculated Cohen’s d values for the differences in proportions, which are interpreted in the same way as Cohen’s d values for differences in means. All differences were calculated as (proportion on Instagram) – (proportion on Flickr). Note that a negative value of Cohen’s d indicates that the proportion on Instagram is smaller than the proportion on Flickr. These values, for the categories used in Figure 1, are summarised in Figure 2. Category Cohen’s d People active 0.82 People posing 1.49 Birds –1.00 Arthropods (insects, spiders, etc.) –1.50 Reptiles –0.44 Figure 2 (b) Interpret, in context, the d-values in Figure 2 for (i) people posing, _____________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________ (ii) reptiles. _____________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________ (3)