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With assistance from a salesman, she tries a number of bikes, and eventually narrows down her options to several different brands and models. She likes all of them, but she can’t decide. Sally would like a very quick and efficient way of looking up information about the bikes she is interested in, comparing specifics about the bikes, and a getting a decent recommendation for which bike to buy. Sally does not want to go home to her computer and search; she would like the opportunity to try out the bikes as wellShe'd like an efficient way to look up and compare information on each. She already at the store, and wants to go home with a bike, not come back after looking up reviews at home on her laptop. She takes out her iPhone and opens Schnap It!
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Having selected the bikes of interest, the program opens a “reviews” shopping cart, Reviews Shopping Cart," which contains a row for each selected bike, along with it’s automatically-determined brand and model number, it’s lowest price from a reliable vendor, and it’s rating from a reliable reviews site. Sally notices that although the Schwin (bottom row) is only $99 online (it’s perhaps it is $169 at the store), that it is also only rated one star.
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She decides to get more information about the more expensive, but highly-rated Trek bicycle. To do so, she simply taps on the arrow in the Reviews Shopping Cart. This brings her to a page that shows price, description, and collections of reviews. After looking over scanning it, she is decides to buy the Trek, right there in the store.
Analysis - Design A
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In this design, the user has a different screen for each decision. The user also must individually take one picture pictures of each object individually. Then Then when all of the pictures have been taken, the user decides which object objects to review together. This choice seems to be irrelevant, because the user should not have spent time taking pictures of object he/she does not want to review. Efficiency isn't the most efficient design since the user isn't likely to take pictures of products she isn't interested in. Efficiency can be improved by aggregating the 'snap picture' and 'choose objects to review' subtasks into less screens. For instance, one picture could be taken and the very next screen shows the shopping cart with information about each object specified.
For the purposes of this application, the user must spend time annotating the picture to specify which object to review. The method of annotation in this design is very quick and efficient. The method of comparing objects is somewhat moderately efficient; if the user wants to compare a specific detail about two objects the user they must travel back and forth between detail screens. The user does not have the ability to move that detail to the shopping cart screen Reviews Shopping Cart where all objects and main details (such as stars) can be viewed.
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Given this application starts by going right to the camera, the user will may not know exactly what to do at the first . Only after time they use the application. We could use a first-use tutorial, or else let them learn by taking a random picture and going through the process will the user to figure out how the application works. This latter scenario detracts from the initial efficiency learnability of learning the application, because there are no blatant instructions for the user to read. In the long run, the user does not have to bypass a repetitive start screen or instruction screen that tells the user what it already knows. The application efficiently starts right out with a camera. After . After taking a picture, the user can touch randomly to learn exactly how to specify which object they are interested in. After specifying, the application reinforces exactly how to take pictures of object and annotate by allowing the simple process to be repeated. This also gives the user practice. Selecting which objects to review is fairly easy to learn. The pictures selected will highlight in some way to show the user exactly what is selected. The arrows on the shopping cart are very good affordances that indicate more on the grid will be highlighted to provide a selection affordance to the user. The arrows on the Reviews Shopping Cart clearly afford a page of additional details. In all, the learnability of this design is fairly good. It allows the user to play on their own and its not too verboselearn by experimentation and stays out of their way.
Safety
Since the efficiency of iPhone applications is very good, the user can correct an issue mistaken view changes fairly quickly by hitting the back button to move up the screen hierarchy. Software architecture on the iPhone make this ability very easy to implement and allows the user for efficient error correction. The to efficiently recover from errors. The user cannot modify information displayed about the objects, separating the backend model from the user model. To the user, the application merely allows a way to quickly look up products for and a simple way of comparing specifics. Errors may occur in the backend, such as the object being recognized is not the object being pictured. This design of the application does not account for this possibility. Modifications should misrecognized, but this design assumes that willl not happen. Modifications could be made for the case when a new object is specified that is not in the database or when the picture taken is not of high enough quality to work for the object detector.
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