Forced choice discrimination tests

Difference testing can be useful tools for assessing panelist s skills. Methods such as the triangle and duo-trio tests are what are communally known as forced choice discrimination tests because panelists are presented with multiple samples and must decide which examples are the same and which are different. These tests can also be used in assessing the impact of changes in supply chain and production techniques. Succinct descriptions of these and other discrimination tests can be found in Bamforth (2014) and Simpson (2006). More in-depth discussions of these techniques are covered by Kilcast (2010), Meilgaard et al. (2007) and Stone et al. (2012). 

The European Test of Olfactory Capabilities (ETOC) (Thomas-Dangnin et al., 2003) or Sniffin Sticks (Hummel et al., 1997). These tests screen for olfactory impairment. The ETOC test consists of 16 blocks of four vials presented one by one to the participants. Only one vial of the four in the block contains an odorant. For each block, participants are asked to point out the odorous vial (forced-choice detection task) and then to identify the odour by choosing a name for the odour out of four proposals (forced-choice identification task). Sniffin Sticks comprises three tests of olfactory function odour threshold (n-butanol), odour discrimination (16 pairs of odorants) and odour forced-choice identification (16 common odorants). 

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