Katie, an MIT Physics junior was working late in J-Lab, as one does, and when she got back to EC she was too tired to cook. Having worked hard for the last several hours, she decided that she deserved a treat, some Thai food. Pepper Sky's seemed like a great call, but she knows from experience that her $11 curry won't meet the $15 delivery minimum. She could order something else, but she is strapped for cash and it would be more fun to eat with some other people. She remembers that great website those kids in that UI class made that perfectly fits this problem, so she loads up Hungr.
She logs in and brings up the new order menu. She clicks the Facebook Connect button and chooses some friends in EC and Senior House. She adds that she wants Thai and is thinking Pepper Sky's, leaves the default join the order time and clicks Go. Across EC and at Senior House, people's new email sounds go off and they see the subject: "Katie is hungr-y for some Thai, are you?". Some of her friends, Kerry, Janet, Tim, and Todd think "Thai is exactly what I need to make this pset suck less", open up the email, and click the link. Other friends have already eaten and don't bother.
After a few minutes pass, every interested is on the choose restaurant screen. There is some discussion about some other Thai restaurants and some nominations, but in the end everyone decides that Pepper Sky's still sounds great. Katie hits the go button and everyone gets the select food screen. Katie adds her chicken curry and Tim adds a scallion pancake. Neither Janet nor Todd are that hungry, so they are looking to split something. Janet adds an order of Duck Choo Chee from the menu and pushes a "half" button. Todd sees the half indicator and thinks that Duck sounds great so he pushes the half button too. Todd adds a Thai Iced Tea and Janet and Katie hit the "me too" button. The order has come together and every body has indicated they are done, so Katie hits go and Foodler opens up with the order all filled out. The main hungr interface switches over to show what everyone owes and has options to inform everyone when the food arrives.
When the food arrives, she hits the button and everyone gets another email "Katie says the food's here. Hope you are still hungr-y". Everybody comes over, pays up, and enjoys the deliciosu Thai food. They are real happy and full.
Learnability: To start up an order, it is quite natural for people to search through list of Facebook friends, as everything is connected to Facebook nowadays. In addition, the general ordering interface will be very similar to that of Foodler (and can be used exactly as such at a base level). Our interface will simply provide simple add-ons that people can choose to use (“me too” “I want to share”). In addition, payment will be the same as usual for online food ordering.
Efficiency: Linking up to Facebook will allow suggested completions of names, as will providing a list of restaurants. This will help organizers suggest things quickly and easily. Selecting restaurants will be facilitate by filter options embedded in the menu (“want” “do not want”) next to restaurants and food types. In addition, allowing people to order simultaneously cuts down on menu reading time and allows for more instant feedback regarding choices.
Visibility: This interface prioritizes important things, including showing a list of people included in the order as well as constraints imposed upon restaurant selection. Showing the constraints allows the user to know whether or not a certain restaurant will be “allowed”. In addition, familiar “vote up/vote down” buttons will perform the obvious action of showing the other users a list of preferences in the right pane.
Errors: Users will have the option to delete items that they don't want from their order, as well as the option to back out entirely. Essentially, one can undo any action up until the time that the order is submitted. If this design goes without a chat box entirely, the users may run into a communication issue if the interface doesn't take into account every desired communication. For example, Janet could have ordered half the duck, but Tim could have clicked the “other half” button first, leaving Todd still wanting to share the duck. In this model, without the chat box, there would be no way for Todd to communicate to Tim that he specifically wanted to share the duck with Janet (ie optimizing food order could be tricky).
Learnability: The process of adding friends is similar to that of adding friends to things on facebook, primarily because it is processed through a facebook interface. The glowing arrows provide a guide as to what the process is, and how it should be followed. A lot of the interface components are similar to those on other sites, e.g. the "doodle-like" restaurant selection frame, so should require little learning.
Efficiency: As with design 1, Facebook will suggest completions of names, and foodler will provide a list of restaurants. This will help organizers suggest things quickly and easily. Filtering options will make this even faster.
Visibility: The process is well demarcated by the "glowing" arrows. The internal information storage (such as selected users and restaurants) is visible at every step, and other users' interactions are also easily visible as the system progresses.
Errors: The system is divided into two primary steps, creating the order and placing the order. In each of these steps the user is able to back up and reverse any of the choices they have made, but they can't usually jump between states. This is alleviated by making the most important details (e.g. participants, restaurant selections) modifiable by all users in the second stage. For example, sharing the link to the page allows one user to add additional people to the order, even after the ordering has begun. The second page only allows adding (and not removing), though, as it ensures that the involved parties will never lose track of what happened in the past and lead to their current state.
Design 3: 
Julian wants to make an order with his friends. he goes to the site and sees the three steps he needs to take to do so.
He picks his restaurant of choice from a drop down list
He searches for groups of friends and select them in groups
He decides that he only wants people to be contacted by email, so unchecks phone and IM.
Everything seems okay to him, so he clicks GO!
Karen is invited to the group via email and clicks on the link she gets.
She is presented with a page with a menu on the left and looks through the choices, gets some rice...
Looks over to what other people are getting...lamb curry! She loves lamb curry, how cold she have forgotten to get that!
Karen adds lamb curry and sees that her total comes out to be $13.52. She clicks Done Ordering at the bottom of the page and waits.
The order is in and Julian sees everyone who is in the order and what they individually need to pay. The others do neo see this.
When people approach him and ask him what they owe, he clicks on their face and tells them.
When they pay, he clicks the paid button unter the price.
Karen gets an email teller to pay Julian 13.52.
She goes over to him, gives him the money, and he checks her off on the above page.
She returns to her computer and sees that she has been marked as paid!
First page visibility/efficiency questionable.