Although not the main focus, Sugiyono introduces mixed-method designs (sequential and concurrent) and explains when and how to combine quantitative and qualitative approaches.

Title: Metode Penelitian Kuantitatif, Kualitatif, dan R&D (Research Methods: Quantitative, Qualitative, and R&D) Author: Prof. Dr. Sugiyono Edition: Commonly cited as the 2017 edition (originally published in earlier editions, e.g., 2009, 2013; 2017 is a frequent reprint/revision). Publisher: Alfabeta, Bandung Language: Indonesian Overview Sugiyono’s Metode Penelitian Kuantitatif, Kualitatif, dan R&D is one of the most widely used and cited methodology textbooks in Indonesian higher education, particularly among students in education, social sciences, management, and public health. The 2017 edition continues the book’s hallmark approach: presenting complex research methodology in a structured, accessible, and highly practical manner.

This section is particularly appreciated for its detailed tables, diagrams, and formulas for calculating sample size (e.g., Slovin formula, Krejcie & Morgan table).