Positioning Graphical Objects on Computer Screens

Abstract

The three-phase model provides a framework for ergonomists to evaluate new positioning techniques and can explain their deficiencies. The model provides a means to analyze tasks and enhance interaction during positioning.

Modeling the Orientation of Graphical Objects on Computer Displays Using Indented Mouse Wheels

“…Figure 4: ET modeled by log 2 (p/t + 1) Confirmation time was inversely proportional to angular tolerance and followed Piéron's Law for the reaction time to a stimulus, suggesting that, during this phase, participants were primarily focused on recognizing that the sector is orientated. In a previous study, one the authors of this paper has demonstrated that the power (β) in Piéron's Law for a one degree of freedom experiment was 0.63 and for a two degrees of freedom experiment was 0.67 (Pastel, 2011). The powers laid in each others 95% confidence intervals.…”

“…This restricts by necessity the experimental studies to relatively large tolerances if the positioned object is to be visible. Pastel (2011) illustrated that the compensation of object width by using tolerance in ID F is not sufficient at small tolerances. The model for MT to precisely position objects required an additional term in inverse tolerance.…”

“…target Pastel (2011) subsequently extended the three phase positioning model to two degrees of freedom and refined the model for confirmation time by applying Piéron's Law, which models the reaction time as a power of the stimulus. Bonnet, Gurlekian, and Harris (1992) found that Piéron's Law fitted well the decrease in reaction time with the size of luminous stimuli.…”

“…We apply Fitts's Law (Fitts, 1954) and a model by Pastel (2011) to illuminate these difficulties. Fitts's Law models the movement time (MT) for a repetitive aiming task by linear regression on an index of difficulty (ID F ).…”

Issues Related to HCI Application of Fitts's Law

“…Blocking of the target conditions certainly is not necessary. Pastel (2011) is an example of a study that randomizes the target conditions. However, of the nine studies cited in Soukoreff and MacKenzie (2004) as examples that have followed ISO 9241-9, the six that we could obtain and that included enough detail to determine how the conditions were ordered, all blocked target conditions.…”