Difference test sensitivity: Comparison of three versions of the duo–trio method requiring different memory schemes and taste sequences

Investigation of operationally more powerful duo-trio test protocols: Effects of different reference schemes

“…Such discrepant pattern of relative test performance between DTF vs. DTM shown in Table 4 indicates the significant effect of tasting order, caused from the given reference position. When considering the duo-trio as a triad in the same way as the triangle test, the S-reference tests correspond to the 'W-odd' triads and the W-reference tests correspond to the 'S-odd' triads (Lee & Kim, 2008;Kim et al, 2010;O'Mahony & Odbert, 1985). The Sequential Sensitivity Analysis (SSA) model predicts that the performance of 'S-odd' will be superior to that of 'W-odd' based on the idea that 'S-odd' has few stronger stimuli, which leads to lower physical adaptation effects (O'Mahony & Odbert, 1985;Thieme & O'Mahony, 1990).…”

“…Only the difference between the DTFR and DTFM represents the ordering (sequence) of the stimuli. Previous studies have found that test performances tend to be higher on the DTFR, despite the possibility that having four stimuli might lead to increased fatigue and memory load (Lee & Kim, 2008;Kim et al, 2010). To investigate whether the performance elicited by the DTFR and DTFM are also different under the different reference mode, the studied eight duo-trio protocols in the present study included the versions of DTF, DTM, DTFR, and DTFM under the two different reference modes: the constant-reference and the balanced-reference.…”

“…1 and Table 1), including the three versions of duo-trio tests which have been reported in previous studies (DTF, DTM, and DTFR) (Rousseau, Stroh, & O'Mahony, 2002;Lee & Kim, 2008;Kim et al, 2010) and a new method developed for this study, 'DTFM'. For the DTFM, subjects were asked to compare the two pairs in a similar manner as in the dual pair test, which is also known as the 4-interval AX (4IAX) in psychology (Kaplan, Macmillan, & Creelman, 1978;Macmillan, Kaplan, & Creelman, 1977).…”

“…Second, the three different versions have been reported according to the schematic formulations of a reference stimulus, varying its position and number. In the present study, these three modified versions of the duo-trio protocols studied, will be denoted 'DTF' (the traditional version, duo-trio with the reference presented first), 'DTM' (duo-trio with the reference presented in the middle of the alternative stimuli), and 'DTFR' (duo-trio with the reference presented twice, first and last as a reminder), following the designations reported in previous studies (Lee & Kim, 2008;Kim, Lee, & Lee, 2010;Rousseau, Stroh, & O'Mahony, 2002).…”

“…For the comparisons across the various versions of the duo-trio, when the same cognitive decision process can be assumed, this d 0 can also be used as an index for test performance. Although all protocols should, in principle, produce the same d 0 estimates when used for food discrimination, one protocol can produce lower values than others due to differences in the operational test power (Chae, Lee, & Lee, 2010;Kim et al, 2010;Kim, Chae, van Hout, & Lee, 2012;Lee et al, 2009;Lee & Kim, 2008;Lee, van Hout, & Hautus, 2007a;Lee, van Hout, & O'Mahony, 2007c;Lee, van Hout, Hautus, & O'Mahony, 2007b). Thus, regarding on the various versions of duo-trio test, it is important to study the effects of the different reference schemes on test performance to investigate the operationally as well as statistically more powerful duo-trio protocol.…”