PS295 Lecture Notes - Lecture 1: Count Data, Categorical Variable, Data Set
Document Summary
What is statistics: statistics has a different meaning for everyone, numbers that represent certain facts. Types of data: categorical data (frequency data, count data, data representing counts or number of observations in each category, measurement data (quantitative data, data obtained by measuring objects or events. Properties of the number system: decimal number system is the one we use, based on numbers 1-10. Frequency tables: frequency table for a categorical variable, usually nominal or ordinal data, example, how many males and how many females are in a class. Graphical representations of data: we can describe a set of numbers in pictorial form, graphical presentation to demonstrate data, describe what scores occurred, frequency of each score. Frequency polygon: replace skinny bars with a point over each score, then connect the points with a straight line, then connect the line to the x-axis.
