Primary - first hand: interviews; questionnaires; observations; experiments
Secondary - pre-existing: official statistics; diaries; letters; memoirs; emails; newspapers' TV documentaries

Quantitative = numbers and statistics; reliable, not very valid

Qualitative = detailed opinions/meanings, subjective; valid but not very reliable

Theoretical:
Positivists want reliable methods, using quantitative methods

Interpretivists want valid methods using qualitative methods

Practical:
Time
Money
Researcher skills
Access/opportunity

Ethical:
consent; deception; confidentiality; avoid harm

Sociologists choose topics based on their preference or area of knowledge

Funding and cooperation

Reviewing the field

Research questions - give focus

Hypotheses - predictions to be tested

Operationalise concepts

Triangulation - combine methods/data

Pilot study - small-scale practice

Sampling

Case studies

Focus groups

Longitudinal studies

Ethnography

statistics

documents/mass media

comparing secondary documents