Effects of learning for linear and differential video magnifiers

Abstract

This study sought to determine the learning effects of repeated practice with the traditional linear and the novel differential linear and differential non-linear magnification methods on visual inspection performance. Performance feedback of speed and accuracy and process feedback of scan paths and coverage of search area were given to subjects in order to facilitate the learning process. Objective performance in terms of speed and accuracy and subjective evaluation using the NASA Task Load Index paradigm were captured and analysed. The results showed that there were positive learning effects for the three magnification methods and the learning effects for the two differential magnification methods were greater than that for the traditional linear method. Three exponential learning curves were established for the three search tasks, which showed that search performance with the differential linear and differential non-linear magnifications would surpass the traditional linear method after four and 10 sessions of repeated practice, respectively.

Effects of Auditory Cues for Linear and Differential Magnification Methods on Visual Inspection Performance

“…In view of the psychophysical properties of human eyes and the variable visual acuity nature of human vision across fovea and periphery, the idea of differential magnification methods was proposed (Lee & Chan, 2009a). Compared with the typical linear magnification method, a past study focusing on the learning effect (Lee & Chan, 2009b) and this study focusing on the auditory cueing effect consistently showed the practicability of the differential magnification methods. The findings of this study have implications for the design of the human-machine interfaces of video magnifiers and are expected to provide valuable insights to human factors engineers and researchers of visual search in understanding and improving the visual inspection process.…”

“…A recent study by the authors (Lee & Chan, ) was recently conducted to examine and compare the effectiveness of the novel differential linear and differential nonlinear methods with the traditional linear magnification method (see Lee & Chan, , for technical details of traditional linear, differential linear, and differential nonlinear magnifying lenses). It was encouraging to find that positive learning effects for the differential magnification methods (−54% of inspection time) were greater than that for the traditional linear method (−44% of inspection time), and the speed for the differential methods were projected to surpass that for the traditional linear method after some repeated practice (Lee & Chan, ).…”

“…The difference in attentional deployment between the traditional linear and differential magnification methods accounted well for the unfavorable consequences of increased inspection time and target misses noted in the differential magnification methods. Since the magnifying lens in the past studies (Lee & Chan, , ) was designed to be smaller than the human's visual lobe area (Chan & Chiu, , ; Tsang, Chan, & Yu, , ), the scaled objects on the magnifying lens could have been discerned in a single fixation. Nevertheless, in the differential magnification methods, attention was deployed at the peripheral area prior to the central area of the lens.…”

Effects of magnification modes and location cues on visual inspection performance

“…The choices of target and non-target characters were basically referenced to past studies of the authors in similar visual search research [30, 34, 35]. Subjects were able to distinguish target from the non-targets while they searched.…”

Effect of Color Contrast on Visual Lobe Shape Characteristics

“…Recent research with the newly developed lobe shape indices had revealed that lobe training with a diffi cult target can produce a noticeable improvement in lobe area and roundness, and search practice with a diffi cult target had a signifi cant eff ect on visual search time (Chan & Chiu, 2009;Lee & Chan, 2009). Interestingly, the lobe roundness for inspectors with experience in microscope-inspection tasks was higher than that for student participants (Chan & Chiu, 2010).…”