Research in social work aims at understanding human behaviour, social problems and effectiveness of interventions through systematic investigation. Two major approaches used in research methodology are quantitative and qualitative research. Both methods help social workers gather reliable knowledge, but they differ in their purpose, design, data collection techniques and analysis procedures. Quantitative research is based on numerical data and statistical analysis. It focuses on measuring variables, testing hypotheses and establishing relationships between different factors. This approach is often associated with scientific and structured methods where information is collected in a standardized format. In social work, quantitative research is useful for studying large populations, evaluating programs and identifying patterns in social issues such as poverty rates, health indicators or education outcomes. The main purpose of quantitative research is to explain phenomena by using objective measurements. Researchers begin with a hypothesis and then collect data to test whether the hypothesis is supported or rejected. For example, a social worker may study the impact of a community development program by comparing income levels of participants before and after the intervention. Such research relies heavily on tools such as surveys, questionnaires and structured observation schedules. Data collection in quantitative research is highly structured. Questions are usually close-ended, allowing respondents to choose from predefined options. This helps in maintaining uniformity and reduces researcher bias. Large sample sizes are preferred because they increase the reliability and generalizability of findings. Sampling