Redundant leading and following zeros in comparative numerical judgment

Area of Science:

• Cognitive Psychology
• Human-Computer Interaction
• Information Science

Background:

• Numerical comparative judgments are crucial for many tasks.
• Numbers with redundant leading or following zeros are common in computer displays (VDT) but under-researched.
• Understanding how these formats affect human processing is important for interface design.

Purpose of the Study:

• To investigate how redundant leading/following zeros and digit string length impact numerical comparative judgments.
• To determine the optimal numerical format for VDTs to facilitate quick and accurate comparisons.
• To explore the processing mechanisms involved in judging numbers with varied zero representations.

Main Methods:

• An experiment was conducted manipulating redundant leading zeros, redundant following zeros, and digit string length.
• Participants judged whether pairs of numbers displayed on a screen were equal or unequal.
• Response times (RT) were measured to assess performance.

Main Results:

• Redundant leading zeros significantly hindered performance.
• The impact of redundant following zeros varied depending on the stimulus type.
• Longer digit strings generally required more processing time.
• Performance improved over trials, with faster RTs in later blocks.
• Identical redundant zero representations in both numbers of a pair facilitated task performance.

Conclusions:

• Redundant leading zeros create processing difficulties in numerical comparisons.
• Nonlexicographic processing, relying on feature identification, occurs when numerical formats are consistent.
• Computer scientists should design numerical formats that minimize cognitive load for comparative judgments on VDTs.