General Business 704 Data Analysis for Managers Introduction The Course, Data, and Excel Instructor/Class Info Kholid eFendi Ins.happy@yahoo.com Ins.happy@hotmail.com Class: http://ins2happy.awardspace.com Course Objectives Master key terminology for data analysis Understand key statistical concepts Master the selection of appropriate statistical tools Master the use of Excel for the calculation of statistics Master the ability to interpret and explain the meaning of statistical findings Have fun Class Motto We will learn no statistic before its time Our focus is on making sense of managerial situations and questions through the use of statistics Course Topics Data Excel Presenting & Describing Data Estimation: Confidence Intervals Hypothesis Testing Simple Regression & Correlation Multiple Regression Bonus Session: Time Series, Forecasting, & Smoothing Readings & Class Time Reading Assignments Ch. 4 & 5 review on your own Ch. 10 covered in OIM 768: Quality Mgmt Ch. 1, 1S, 2, 3, 6, 7, 8, & 9 overview Ch. 11 & 12 covered in depth Ch. 13 for reference purposes Class Time Lecture & Discussion Demonstrations Application Practice Assignments Homework Individual & Team Cases Demonstrate ability to do requested tasks Demonstrate ability to: identify & apply appropriate tools; & interpret/explain findings Team Project Demonstrate ability to: develop good questions; identify appropriate data; identify & apply appropriate tools; & interpret/explain findings Exams Exam #1 Wednesday 9/23 Covers material through Chapter 9 Final Exam Wednesday 10/21 Covers all course material Grading Activity Homework #1 Homework #2 Homework #3 Individual Case #1 Individual Case #2 Team Case Team Project Exam #1 Final Exam TOTAL POINTS Points 50 50 50 100 100 100 250 100 200 1000 Objectives: Data & Excel Define statistics Distinguish descriptive & inferential statistics Summarize the sources of data Describe the types of data & scales Explain the types of samples Describe survey process & errors Discuss the use of Excel Some Important Issues Collecting data e.g., Survey Presenting data Data Analysis Why? e.g., Charts & tables © 1984-1994 T/Maker Co. DecisionMaking Characterizing data e.g., Average © 1984-1994 T/Maker Co. Application Areas Accounting Auditing Costing Management Finance Financial trends Forecasting Describe employees Quality improvement Marketing Consumer preferences Marketing mix effects Statistical Methods Statistical Methods Descriptive Statistics Inferential Statistics Descriptive Statistics Involves Collecting data Presenting data Characterizing data 50 $ 25 0 Q1 Purpose Describe data Q2 Q3 Q4 _ X = 30.5 S2 = 113 Inferential Statistics Involves Estimation Hypothesis testing Purpose Make decisions about population characteristics Population? Some Key Terms Population (universe) Sample • S in Sample & Statistic Portion of population Parameter All items of interest • P in Population & Parameter Summary measure about population Statistic Summary measure about sample Why Collect Data? Obtain input to a research study Measure performance Assist in formulating decision alternatives Satisfy curiosity Knowledge for the sake of knowledge Data Types Data Numerical Categorical (Quantitative) (Qualitative) Discrete Continuous Data Type Examples Numerical Discrete To how many magazines do you subscribe currently? ___ (Number) Continuous How tall are you? ___ (Inches) Categorical Do you own savings bonds? __ Yes __ No How Are Data Measured? Nominal scale Categories e.g., Male-female Count Ordinal scale Categories Ordering implied e.g., High-low Count Interval scale Equal intervals No true 0 e.g., Degrees Celsius Measurement Ratio scale Equal intervals True 0 Meaningful ratios e.g., Height in inches Data Sources Data Sources Secondary Primary Experiment Survey Observation Published (& On-Line) Basic Survey Steps Define purpose Design questionnaire Collect data (field work) Prepare data Select sample design Sample type Sample size Edit Code Analyze data Interpret findings Report results Questionnaire Design Question content Mode of response Question wording Question sequence Layout Pilot testing © 1984-1994 T/Maker Co. Why Sample? Destruction of test units Quality control Accurate & reliable results Pragmatic reasons Time Cost Types of Samples Type of Sample Non Probability Probability Simple Random Judgment Quota Chunk Systematic Stratified Cluster Types of Samples Type of Sample Non Probability Probability Simple Random Judgment Quota Chunk Systematic Stratified Cluster Simple Random Sample Each population element has an equal chance of being selected Selecting 1 subject does not affect selecting others May use random number table, lottery, ‘fish bowl’ © 1984-1994 T/Maker Co. Random Number Table Column Row 00000 12345 00001 67890 11111 12345 11111 67890 01 49280 88924 35779 00283 02 61870 41657 07468 08612 03 43898 65923 25078 86129 OR: Use Excel to generate random numbers Types of Samples Type of Sample Non Probability Probability Simple Random Judgment Quota Chunk Systematic Stratified Cluster Systematic Sample Every kth element Is selected after a random start within the first k elements Skip interval, k, is Population size Sample size Used in telephone surveys © 1984-1994 T/Maker Co. Types of Samples Type of Sample Non Probability Probability Simple Random Judgment Quota Chunk Systematic Stratified Cluster Stratified Sample Divide population into subgroups Mutually exclusive Exhaustive At least 1 common characteristic of interest Select simple random samples from subgroups All Students Commuter s Residents Sample Types of Samples Type of Sample Non Probability Probability Simple Random Judgment Quota Chunk Systematic Stratified Cluster Cluster Sample Divide population into clusters Companies (Clusters) If managers are elements then companies are clusters Select clusters randomly Survey all or a random sample of elements in cluster Sample Types of Samples Type of Sample Non Probability Probability Simple Random Judgment Quota Chunk Systematic Stratified Cluster Nonprobability Samples Judgment Use experience to select sample Example: Test markets Quota Similar to stratified sampling except no random sampling Chunk (convenience) Use elements most available Errors Due to Sampling Coverage (Frame) Error Sampling Error Nonresponse & Measurement Error Total Population (Students) Sample Frame (Students in Phone Book) Planned Sample (Selected Students) Actual Sample The Use of Excel Microsoft Excel 97 Windows/ 98 Mac Graduate Lab has Excel 97 Our analyses done with Excel 97/98 Data disk with book for practice Study Chapter 1S Review update to 1S for Excel 97 Objectives: Data & Excel Define statistics Distinguish descriptive & inferential statistics Summarize the sources of data Describe the types of data & scales Explain the types of samples Describe survey process & errors Discuss the use of Excel Course Objectives Master key terminology for data analysis Understand key statistical concepts Master the selection of appropriate statistical tools Master the use of Excel for the calculation of statistics Master the ability to interpret and explain the meaning of statistical findings Have fun