Quantitative research involves counting and measuring to obtain precise results about a situation. Questionnaires are a common tool used, which involve defining a problem, developing questions, pretesting the questionnaire, distributing it with a cover letter, and following up with non-respondents. Questionnaires have advantages like broad coverage and economical administration but disadvantages like low response rates and inability to clarify ambiguous questions. Questions can be open-ended or structured with fixed responses, and scaling techniques like Likert scales are used to differentiate opinions. Question placement within the questionnaire is also important.