math215 Lecture Notes - Lecture 1: Categorical Variable, Pie Chart
Document Summary
Data collection is a process of gathering information using questionnaires, interviews, experiments, and field study. Data may be collected from two main sources; primary and secondary. Involves raw or original data that are collected directly from the respondent. For example participants from a survey using various instruments such as interviews, surveys etc. There are two types of data quantitative and qualitative. Quantitative data (numerical data: deals with numbers, data which can be measured, length, height, area, volume, weight, speed, time, temperature, humidity, sound levels, cost, members, ages, etc, can either be discrete or continuous. Discrete data can only take certain values (like whole numbers) Continuous data can take any value (within a range) For example a survey asking students to rate their professors as excellent, good, fair or poor. The measurement scale for qualitative (categorical) data is nominal and ordinal. The measurement scale for quantitative (numerical) data is interval and ratio ratio.
