Quantitative Data

Qualitative Data

Random Sampling

Strengths of Random Sampling

Weaknesses of Random Sampling

Stratified Random Sampling

Strengths of Stratified Random Sampling

Weaknesses of Stratified Random Sampling

Quota Sampling

Strengths of Quota Sampling

Weaknesses of Quota Sampling

Experiments

Strengths of Experiments

Weakness of Experiments

Questionnaires

Strengths of Questionnaires

Weaknesses of Questionnaires

Structured Interviews

Strengths of Interviews

Weaknesses of Interviews

In-depth Interviews

Strengths of In-depth Interviews

Weaknesses of In-depth Interviews

Observation (Covert/Overt)

Strengths of Observations

Weaknesses of Observations

Participant/Non-participant Observation

Strengths of Participant Observation

Weaknesses of Participant Observation

Reliability

Validity

Bias

Problems with methods used for collecting data

Ways of overcoming data-collection problems

Ethical issues involved in collecting data and researching families and individuals