Increasing or decreasing? The menu direction effect on user performance

Although the breadth/depth issue in menu design has been identified to have significant effects on user performance, the effects of menu direction and dimension have not been well investigated, especially as iconic menus as concerned. This study investigated the effects of menu direction and dimension on user selection performance by using two different dimensions (sizes) of iconic menu systems (16·item and 32·item). The direction of the menus consisted of 'increasing' and 'decreasing', with the depth of menu ranging from 2 to 3 levels. The findings indicated that 'decreasing' direction menus were significantly quicker and more accurate than 'increasing' menus. However, for the smaller size menus (16 item menus), user performance accuracy was better with the 'increasing' direction menus. Overall, the results showed that 'decreasing' direction menus are superior to 'increasing' menus. It is suggested that for small size iconic menus (e.g., up to 32 items), items should be organized in 'decreasing' direction, especially when speed is of particular importance to the selection task.