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Evaluation:
Learnability:
This design favors learnability, since it has an initial welcome screen with descriptions on what to do. There are some things that are not as learnable though. For instance, the check boxes on the food page that allow a user to search for a recipe from those items has no affordances. A user would have to click them to find out what happens, or go through a tutorial.
The toolbar at the bottom is also unusual. Although it makes things more visible and efficient in the long run (since it floats and is always visible), it is a little more difficult to get used to than more popular navigation methods, with selection on the top or left side.
Visibility:
In general, most things are visible in this design. Each page displays all the information at once. An example of this is that the recipe page shows recipes returned from the search (or if there was no search then popular recipes or recipes you can make) on the left, and specific recipe details on the right. This omits lots of clicking the back button to see the list again (which increases efficiency also).
Efficiency:
The check boxes on the food page are an example of choosing efficiency over learnability. Since the user only has to learn this feature once, and it is a more advanced feature, he can check items more quickly than going to the recipe page and entering that information there.
Error Prevention:
One of the things designed for error prevention was putting the check box for recipe searching on the left of the food items, instead of the right. Putting this on the right would mean it is near the delete button, and that could cause errors. This design tries to keep those types of buttons apart. A weakness of this design in this area is