RESEARCH Q3

1. Data Collection Methods
  • Interviews (Face-to-Face, Telephone, CAPI): Provide detailed insights but can be time-consuming and expensive.

  • Questionnaires (Paper-Pencil, Web-Based): Cost-effective and anonymous, but may suffer from low response rates.

  • Experimental Method: A controlled study to establish cause-and-effect relationships; highly reliable but time-intensive.

  • Observational Study: Records real-time events, reducing bias but potentially difficult to interpret.


2. Data Organization

Definition: The process of classifying and structuring data for better usability.

Ways to Organize Data:

  • Graphs

  • Charts

  • Tables

  • Pictures

  • Graph: A visual representation of data relationships.

  • Chart: A structured display of data in tables, graphs, or diagrams.


3. Types of Graphs
  • Bar Graph: Represents independent values.

  • Line Graph: Displays trends and changes over time.

  • Cartesian Graph: Uses numerical axes to illustrate relationships, commonly used in algebra.


4. Definition of Statistics

Statistics involves the design of experiments, data collection, classification, organization, interpretation, and decision-making. It is divided into:

  • Descriptive Statistics: Summarizes and presents data using graphs, tables, measures of central tendency, and variability.

  • Inferential Statistics: Makes predictions about a population based on a sample.


5. Measures of Central Tendency

A single value representing a dataset:

  • Mean: The average of all values.

  • Median: The middle value when data is arranged in order.

  • Mode: The most frequently occurring value.


6. Measures of Variability

Indicates how spread out the data is:

  • Range: The difference between the highest and lowest value.

  • Mean Deviation: The average of absolute differences from the mean.

  • Variance: The mean of squared deviations from the mean, useful for statistical comparisons.

  • Standard Deviation: Measures the average distance of data points from the mean.

Sample Standard Deviation (n-1)

Using n-1 instead of n provides a more accurate estimate of population variability, reducing bias in small samples.

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