DATA ² COLLECTION, CLASSIFICATION & REPRESENTATION
Data
Data can be described as unstructured raw facts, observations or unevaluated messages in isolation Data are facts & figures which are not currently being used in decision process Information is defined as data that is collected, processed, logically organized and analyzed so as to be of use to the decision maker
Information
Information brings clarity and creates an intelligent human response in the mind Some of the characteristics of Information:
± Improves representation of an entity ± Updates the level of knowledge ± Has a surprise value ± Reduces uncertainty ± Aids in decision making
Information Process
Capturing Verifying Classifying Arranging/sorting Summarizing Calculating Storing Retrieving Reproducing Dissemination / Communication
Types of Data
Primary Data
± Data collected for the first time by the researcher ± Techniques include observations, questionnaires, interviews, etc
Secondary Data
± Data borrowed by the researcher from other sources
Primary data collected by one person may become the secondary data for another
Types of Data
Qualitative Data:
± Data that are expressed by a non-numerical property ± For example
Satisfaction of a customer Rich Poor
Quantitative Data:
± Data that are numerically expressed ± For example:
Weight Height Income Expenditure
Types of Data
Further more, Quantitative Data are again of two types:
± Measurements or Scores ± Frequencies
Some terms to be remembered
Population: All possible observations Sample: A portion of population, taken for further analysis and are used to draw conclusions Parameter: Characteristics of whole population Statistic: Characteristics of sample and is presumably measurable Variable ± Continuous and Discrete Constant Domain
Secondary Data
Advantages of Secondary Data Disadvantages of Secondary Data Sources of Secondary Data
Primary Data
Two main methods to collect primary data are Observation and Communication OBSERVATION: Advantages and Limitations COMMUNICATION: Questionnaire
Questionnaire
Types of Questionnaire: Structured / Nonstructured ± Disguised/Non-disguised Designing a Questionnaire:
± Type of information to be collected ± Type of questions ± Open ended, Dichotomous and MCQ ± Phrasing of the questions ± Order of questions ± No. of questions ± Layout of the questionnaire
The Frequency Table: Discrete Series
Relative Frequency Class Limits Class Interval Class Frequency Class mid-point
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Methods of Classifying Data
Exclusive Method Inclusive Method
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Formation of a Grouped Frequency Table
The formation of a frequency distribution table comprises the following steps: 1. Deciding the groupings appropriate number of class
2. Choosing a suitable size or width of a class interval 3. Establishing the boundaries of each class interval 4. Classifying the data into the appropriate classes 5. Counting the number of items (i.e. frequency) in each class.
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Relative Frequency and Percentage Distributions
Frequency Relative Frequency = Total Number of observations
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Cumulative Frequency Distribution
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Two-Way and Three-Way Frequency Distribution
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Main Parts of a Statistical Table
Guidelines Regarding Structure of a Table Table Number Title Captions and Stubs Main Body of the Table Ruling and Spacing Head Note Footnote Source-note
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