Learnability
This design has a moderate learning curve without help messages. There are only two pages: Tasks and Groups. On the Tasks page, the user sees upcoming tasks which he can sort by various criteria and on the Groups page he adds his information. Not knowing anything about the JobTracker system, a new user might be confused about what he's supposed to do.
On an empty groups page, a user would see the "+ Group" button, but might not realize that they have to add groups to get started. One way to fix this would be to have a default group on the Groups page. Also, since a user can add both Companies and Documents to a Group, the add button simply says "+ Item". This lack of clarity might be confusing to a novice user.
However, once a user adds a company and clicks on it, the company fields are self-explanatory. The edit area pops up as soon as the user clicks on a "+" button and allow the user to enter information in a straightforward fashion. Also, we provide dropdown menus with options for task types, allowing even a new user to easily add tasks for a particular company.
Visibility
Currently, this design defaults to showing the Tasks list upon login. Since there is currently no way to add a task directly to this list, it might be unclear how this list is to be populated. A home page with explanatory text would clear up this issue.
On the Groups page, it is very easy to glance over entered information at a high level because of the view hierarchy. Also, modes are easy to determine since editing happens right on the page.
Efficiency
Adding a new piece of information requires a few clicks each time. So, while it's easy to get started, repeating a task requires unnecessary clicks. If the user wants to data enter information from many companies, it might take him unnecessarily long. We could solve this problem by adding "save and add another" buttons to the editing areas for Tasks, Companies, Contacts etc.
Error Prevention
The worst error a user can make with this system is entering in a piece of information wrong. If this happens, a user can easily backtrack by editing this information to make it correct.