Basic Data Analysis: Descriptive Statistics

Coding Data and the Data Code Book Data entry refers to the creation of a computer file that holds the raw data taken from all of the questionnaires deemed suitable for analysis Data coding refers to the identification of codes that pertain to the possible responses for each question on the questionnaire Data code book identifies all of the variable names and code numbers associated with each possible response to each question that makes up the data set Ch 15

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Types of Statistical Analyses Used in Marketing Research Data summarization: the process of describing a data matrix by computing a small number of measures that characterize the data set Ch 15

Types of Statistical Analyses Used in Marketing Research Four functions of data summarization: Summarizes the data Applies understandable conceptualizations Communicates underlying patterns Generalizes sample findings to the population Ch 15

Why is Statistical Analysis Used? Why Use Statistical Analysis? To summarize data The average price of a Gateway PC is $2,489 The low is $999, and the high is $4,678: this is the range The mode is $2,200 Ch 15

Why is Statistical Analysis Used? Why Use Statistical Analysis? To show basic patterns in the data 30% buys at $1,500 or less 50% buys at between $2,500 and $1,500 20% buys at $2,500 or more Ch 15

Why is Statistical Analysis Used? Why Use Statistical Analysis? To interpret these patterns The majority of Gateway buyers pay $2,500 or less Ch 15

Why is Statistical Analysis Used? Why Use Statistical Analysis? To generalize the patterns to the population 95% of all Gateway buyers pay between $2,000 and $3,000 for their PC’s Ch 15

Types of Statistical Analyses Used in Marketing Research Statistical Analysis: Ch 15

Types of Statistical Analyses Used in Marketing Research Five Types of Statistical Analysis: Descriptive analysis: used to describe the data set Inferential analysis: used to generate conclusions about the population’s characteristics based on the sample data Ch 15

Types of Statistical Analyses Used in Marketing Research Differences analysis: used to compare the mean of the responses of one group to that of another group Associative analysis: determines the strength and direction of relationships between two or more variables Ch 15

Types of Statistical Analyses Used in Marketing Research Predictive analysis: allows one to make forecasts for future events Ch 15

Understanding Data Via Descriptive Analysis Two sets of descriptive measures: Measures of central tendency: used to report a single piece of information that describes the most typical response to a question Measures of variability: used to reveal the typical difference between the values in a set of values Ch 15

Understanding Data Via Descriptive Analysis Measures of Central Tendency: Mode: the value in a string of numbers that occurs most often Median: the value whose occurrence lies in the middle of a set of ordered values Mean: sometimes referred to as the “arithmetic mean”; the average value characterizing a set of numbers Ch 15

Understanding Data Via Descriptive Analysis Measures of Variability: Frequency distribution reveals the number (percent) of occurrences of each number or set of numbers Range identifies the maximum and minimum values in a set of numbers Standard deviation indicates the degree of variation in a way that can be translated into a bell-shaped curve distribution Ch 15

Understanding Data Via Descriptive Analysis Measures of Variability: Ch 15

When to Use a Particular Statistic Ch 15