This document discusses various quantitative and qualitative market research methods for sizing, segmenting, and forecasting markets. It describes collecting primary or secondary quantitative data through surveys or existing data sets to understand what, where, when questions factually. Qualitative research involves open-ended questions to understand why and how through expert opinion, ethnography, or focus groups. The document outlines demographic, behavioral, and psychographic segmentation of people markets and firmographic segmentation for business-to-business markets. It provides guidance on market sizing, determining market share, and producing forecasts based on analyzing historical time series data patterns.