EXAM Part 1: Assignment © The University of Melbourne INFO90002 EXAM PART 1 S2 2020 3 Question 1: Modelling from a case study (30 marks) A system to support “Experience Sampling” research We are building a software system to support Experience Sampling experiments. In these experiments, a group of human participants fill in the same survey (set of questions), several times per day over multiple days. (Questions typically ask about what the person is doing or feeling.) Participants have an app on their phones that retrieves the questions from the database, displays the questions, accepts answers from the user, and sends the answers to the database to be stored. All relevant data, including details about researchers and participants, experiments and surveys, questions and answers are stored in the database. To set up a new experiment, a researcher specifies a start and end date, the set of questions and the order to display them in, and the number of times per day they should be sent to participants. The researcher then recruits participants and stores their details in the system. When the start day arrives, the system will begin to send surveys to participants. Each survey is the full set of questions specified by the researcher for that experiment. We need to keep track of each survey that is sent out, including when it was sent and to whom. When a participant responds to a survey, we need to store the answers, remembering when the answers arrived, and which answers came from which participant. (Note that participants don’t necessarily respond to each survey.) Figure 1 shows a survey consisting of 3 questions, displayed on a participant’s phone. Questions can ask for three possible types of answer: short-text, numerical (integers zero or above), and multiple-choice. For short-text questions, the researcher specifies the maximum number of characters allowed, while for numerical questions, they specify the maximum number. For multiple-choice questions, they specify the list of possible answers. (The longest short-text our system allows is 1,000 characters, while the biggest maximum number we allow is 10,000.) Multiple researchers will use our system, each of whom can set up as many experiments as they want. Over time we will build up a bank of questions (and for the multiple-choice questions, answers), and we want to allow these to be re-used in multiple experiments. It’s possible that a given participant might take part in more than one experiment. Researchers and participants need to store a username and email address in the system. We allow researchers to give a name to each experiment, such as “Bob’s Masters project”. During the life of our system we anticipate having around 1,000 researchers who will run an average of 10 experiments each, with around 100 participants per experiment. Experiments contain on average 5 questions and run for 30 days. Figure 1: A survey consisting of one short-text question, one numerical question, and one multiple-choice question. EXAM Part 1: Assignment © The University of Melbourne INFO90002 EXAM PART 1 S2 2020 4 Q1. You are asked to model a physical Model of the Experience Sampling app in Crows Foot Notation for a MySQL v8.0 Relational Database using MySQL Workbench. State any assumptions you have made. (30 marks)
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