Subjective ratios and differences in perceived heaviness.

Area of Science:

• Psychology
• Psychophysics
• Sensory Perception

Background:

• Previous research suggested a single perceived relation underlies judgments of subjective magnitude for both ratios and differences.
• Ordinal discrepancies between ratio and difference estimates were observed, prompting further investigation.

Purpose of the Study:

• To investigate whether subjective magnitude judgments of heaviness ratios and differences are based on one or two distinct perceived relations.
• To derive a ratio scale of heaviness by combining subjective ratio and difference estimates.

Main Methods:

• 15 subjects estimated heaviness differences between pairs of weights.
• 8 groups of 10 subjects evaluated heaviness ratios relative to standard stimuli.
• Stimuli were presented on a cube-root scale of weight.
• Non-metric analyses were employed to examine scale differences.

Main Results:

• Ordinal discrepancies between ratio and difference estimates were enhanced by specific stimulus scaling.
• Differences in estimate orders and scales indicated two distinct perceived relations.
• These relations were ordinally consistent with arithmetic operations for ratios and differences.

Conclusions:

• Subjective judgments of heaviness ratios and differences are based on two distinct perceived relations.
• A unified ratio scale of heaviness can be derived from combined subjective ratio and difference data.