7/27/03 Copyright Ed Lipinski and Mesa Community College, 2003-2009. All rights reserved.

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Research MethodsSummer 2009

Describing Data

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Agenda

• General Housekeeping

• Assignments

• Lesson Objective

• Ed’s Overview / Discussion

• Questions.

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Assignments

• Read Chapters 14 in the Text• Using Inferential Statistics.

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Objective

• “... to review descriptive statistics”

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Ed’s Overview

• I. Exploratory Data Analysis

• II. Organizing Data

• III. Graphing Data

• IV. The Frequency Distribution

• V. Descriptive Statistics

• VI. Measures of Association.

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I. Exploratory Data Analysis

• A. Searching For Patterns In Your Data• B. Resist Temptation• C. Spot Defects.

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II. Organizing Data

• A. Data Management Done First• B. Using a Data Sheet (see B &A)• C. Computer Entry Prep

• Dependent On Package• Entering Data• Grouped Data• Individual Data.

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III. Graphing Data

• A. Data In a Two-Dimensional Space • B. Bar Graphs – Good For Categorical• C. Line Graphs – Multifactor Experiments• D. Scatterplots – Correlations• E. Pie Charts – Proportions or Percents• F. Importance of Graphing

• Showing Relationships Clearly• Choosing Appropriate Statistics.

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IV. The Frequency Distribution

• A. Allows You To Sort Data• B. Displaying Information

• The Histogram• The Stemplot

• C. Examining Your Distribution• Skewed• Normal• Outliers.

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V. Descriptive Statistics

• A. Measures of Center• The Mode• The Median• The Mean

• B. Choosing a Measure of Center• Two Factors

• Scale of Measurement• Shape of the Distribution.

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V. Descriptive Statistics

• C. Measures of Spread• The Range• Standard Deviation

• D. Choosing a Measure of Spread• Shape of the Distribution.

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VI. Measures of Association

• A. Pearson Correlation

• B. Point-Biserial Correlation

• C. Spearman Rank Order Correlation

• D. Linear Regression and Prediction.

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Recap

• I. Exploratory Data Analysis

• II. Organizing Data

• III. Graphing Data

• IV. The Frequency Distribution

• V. Descriptive Statistics

• VI. Measures of Association.

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Describing Data

Questions