Contrast and Range Effects for Category,Magnitude and Labeled Magnitude Scales in Judgements of Sweetness Intensity

摘要

The labeled magnitude scale (LMS) is a verbally anchored quasi-logarithmically spacec rescorse s:e~e oh oroperties similar to magnitude estimation. Three experiments examined whether the LMS showed cortex: effe:ts ~- a- :o those found with magnitude estimation and category scales. Two versions of the LMS were used, one anchcreo a: :~e on eno to the strongest imaginable sweetness and the other to the strongest imaginable oral sensation. In a s~mpIe ccrt-ast excerment, subjects judged the sweetness of a 10% sucrose fruit beverage in the context of a less sweet (5%) beverage or a more sweet (20~/o) beverage. Consistent with previous literature, the sweetness was judged more intense in the low context and ass terse n the high context, for all scaling methods. In a second experiment, this effect persisted (although was smaller,’ v~.her n-a cortextual item preceded the to-be-rated item, a so-called ‘reversed-pair’ design. Once again, the effect was highly s~gn~icant for all scaling methods. In a third experiment, a range effect was examined using wide and narrow ranges of concer’:ratrcr~ cs.cho~ physical functions were flatter in a wide context and steeper in a narrow context, consistent with previous obseratior’s on range-mapping bias. This result was obtained for all scales. In three common contextual effects, the labeled macn :uce scale behaved similarly to other scaling procedures. Its application to comparisons across individuals may be limiteo ~ those individuals have different experiential contexts within which they make their judgements.