24 Nov 2007Data Management1 Data Summarization and Exploratory Data Analysis Objective: Describe or Examine Data Sets in Term of Key Characteristics

24 Nov 2007Data Management2 Key Characteristics Majority and Minority Distribution or Pattern Typical or Most Frequent Values Variability Highest and Lowest Values Unusual or Extreme Values

24 Nov 2007Data Management3 Methods for Data Summarization Graphical Method Numerical Method

24 Nov 2007Data Management4 Graphical Method Bar chart Pie chart Histogram Stem and leaf plot Box plot Scattered plot Time sequence plot

24 Nov 2007Data Management5 Numerical Method Frequency or Relative Frequency Measures of Central Tendency Measure of Spread or Variability

24 Nov 2007Data Management6 Measure of central tendency Mean Median Mode Trimmed Mean

24 Nov 2007Data Management7 Measure of spread or variation Variance or Standard Deviation Range Inter-quartile Range

24 Nov 2007Data Management8 Types of Data Qualitative Data Quantitative Data

24 Nov 2007Data Management9 Qualitative Data Definition: Measurements that classify a population or a sample unit into one of a group of categories. Examples: - Sex, Occupation, Educational Level, Race, Nationality - Political Party Affiliation - Defective Status of Manufacturing Items

24 Nov 2007Data Management10 Quantitative Data Definition: Measurement that are recorded on a naturally occurring numerical scale. Example: - Weight, Height, Age, Blood Pressure, Pulse Rate - Temperature

24 Nov 2007Data Management11 Counted Data Definition: Total number of sample or population units that have specific characteristics or attributes. Examples: - Total number of male students in class - Total number of car accidents at an intersection during the week - Total number of households in Thailand with children age under 15 - Total number of HIV infected from 500 blood samples

24 Nov 2007Data Management12 Case study Aphasia is the impairment or loss of the faculty of using or understanding spoken or written language. Three types of aphasia have been identified by researchers: Broca’s, conduction, and anomic. The objective of the study is to determine whether one type of aphasia occurs more often than any other, and if so, how often. Consequently, a sample of 22 adults aphasiacs was selected and aphasia type of each was diagnosed. Data is as follow:

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24 Nov 2007Data Management14 Procedure Frequency Counts and Percentage Bar Chart Good Representative Inference

24 Nov 2007Data Management15 Case study The Environmental Protection Agency (EPA) performs extensive tests on all new car models to determine their mileage ratings. Followings are 100 measurements represent the results of such tests on a certain new car model (miles per gallon).

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24 Nov 2007Data Management17 Procedure Descriptive Statistics Stem and Leaf Plot, and Box Plot Typical Value and Variation Extreme Values

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24 Nov 2007Data Management22 ColorGoldGrayBlackRedGreenBlueWhite Cars

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24 Nov 2007Data Management24 Application in Survey Data Structure of Sample Data Good Representative Investigation of Each Variable in Each Cluster Frequency Distribution Typical Value and Variation Extreme Values Non-weighted Tabulation