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