The screenshots of the 1987 Mac desktop, the 2005 Mac OS X desktop and the 2010 first iPad interfaces all have different ways of manipulating objects on the interface as a mode of interaction. The 1987 Mac Desktop has a very simple GUI interface with windows, icons, and menus. Direct manipulation of these objects required a physical controller such as a mouse and keyboard to select, move, open and close objects. However, the 2005 Mac OS X desktop interface had improved features and while the user still used a mouse and keyboard to manipulate directly the interface, there were more advanced interactions such as shrinking, and stretching the icon on the icon dock, and zooming and out to automatically resize icons. In the 2010 iPad direct interaction involves touch, and here the user has more flexibility since the user can use touch gestures to manipulate the interface. The traditional move, select, open and closing of objects is done using touch actions while zooming, shrinking and resizing uses gestures such as pinch to zoom.
Comparing a paper-based vs. a shared digital calendar.
The digital calendar uses the same interface concepts and metaphors like the paper-based calendar in that it has dates, covers and the ability to mark and add events. However, there is a significant difference in terms of interaction. Information is added to the paper-based calendar by writing while the digital calendar uses different recording means such as keyboard, stylus, video, audio, and images. The digital calendar also uses gestures and buttons to navigate and manipulate objects. In terms of flexibility, a digital calendar is saved as electronic data which can easily be stored, modified and transferred. For example, it is easy to synchronize the data on a digital calendar across various devices such as smartphones and computers, and access the data anywhere via the internet. Digital calendars also have data search features that make it easy to find information accurately.
Google and Microsoft’s Bing search engine homepages found at www.google.com and www.bing.com have very simple interfaces employing user-centric designs aimed at enhancing cognition by drawing user attention to the search bars. The Google homepage had a simple interface with the Google banner, a search bar, and two buttons i.e. Search, and I’m Feeling Lucky. The presence of a single search bar on a plain white page with two buttons below it clearly communicate that the user should type in their search keywords in the search bar and use the appropriate button to search. The Bing search homepage employs a similar technique where a large search bar with a magnifying glass button to show search is presented. The search bar is white with a background image thus creating sharp contrast and clearly indicating the search bar location.
When comparing Bailey’s arguments to Miller’s findings, it appears that Bailey’s arguments are well-founded while Miller’s findings are flawed. Miller’s findings are based on theories on the Magic Number 7 where interface design decisions are made based on one absolute and generalized rule. However, Bailey points out several research outcomes where the total number of items a person can remember for a short time has been found to be 3-4 items. In this regard, the optimal number of menu items during interface design should not be based on a generally accepted rule that works for all. Based on analysis of Bailey’s arguments, it is clear that the number of menu items relies majorly on the short-term working memory which varies from person to person based on cognitive skills such as reasoning and drawing inferences from text.
