OPRE 3360: Managerial Methods in Decision Making Under Uncertainty OPRE 3360: Managerial Methods in Decision Making Under Uncertainty Class 1: Introduction to Data Description Synopsis, Cases, and Class note Prepared by Qi, Copyrights reserved. OPRE 3360: Managerial Methods in Decision Making Under Uncertainty Synopsis of Class 1 (Intro. to Data Description) Data and statistics are the foundation of any business analytics. Therefore, before we learn any decision support tools, it is useful for us to articulate a few important concepts. In particular, we will learn • • • • What is statistics? What is the concept of data? How do we classify the data (categorical or quantitative)? What do we mean by data set? What are the elements, variable, and observation in a data set? What are the scales of measurement in data collection? What is the relationship among the four scales of measurement: nominal, ordinal, interval and ratio? How are the scales of measurement related to the type of data? With the concepts above articulated, we will move on to the tabular and graphic description of data. In particular, we will first introduce the concepts of frequency distribution, relative frequency distribution, and percentage frequency distribution. Then, when the data are categorical, we will introduce the bar chart, Pareto diagram and pie chart. When the data are quantitative, we will learn the histogram and cumulative distribution. Prepared by Qi, Copyrights reserved. OPRE 3360: Managerial Methods in Decision Making Under Uncertainty Mini Case: The Data of Movies There have been tons of data available in different databases. For a movie fan, information about a particular movie can be easily found on IMDb and other websites such as Rotten Tomatoes. These databases are very useful especially when you need to find a particular fact to convince your friend in an argument, for example, in the following scenario. A (an engineer): “Despicable Me 3 is so awesome! I bet more people are in favor of it over Zootopia. These minions are just… despicable!” B (a professor):“Er… I like Zootopia more. I believe it completely dominates the yellow minion movie by not only the support of ordinary audience, but also critics! I think it is even better than the best animated movie last year, Inside Out, and some other movies nominated for the best picture in 2017, like La La Land.” Who do you think is right? A or B? Task 1: Data Collection: Collect data about the movie Zootopia from the website of Rotten Tomatoes (http://www.rottentomatoes.com/), and fill the blank below. Movie Type Rating Year Box Office ($M) Tomatometer Audience Rating La La Land drama PG-13 2016 $151.1 91% 81% Inside Out animation PG 2015 $264.3 98% 89% Despicable Me 3 animation PG 2017 $264.2 58% 54% Zootopia Based on your collected data, who is right? Task 2: With the data of Zootopia collected, you already collected a data set of four movies. Then think about the following questions (you do not have to answer these questions) (1) What are the elements, variables, and observations in the data set? (2) What are the scales of measurements of these variables: Type, Year, Rating, Box Office, Tomatometer, and Audience rating? Remark: These data about movies are not only useful in settling dispute among friends, but they are also very helpful in scientific research. Prof. Huaxia Rui, Simon School of Business, University of Rochester, leveraged data collected from Tweeter and box office data and showed that “by observing the number of positive tweets after opening weekend, we could have predicted that the movie would continue to generate revenue in the coming weeks.” 1 1 http://online.wsj.com/news/articles/SB10001424052970204731804574391102221959582 Prepared by Qi, Copyrights reserved.
