Used in market research surveys - mainly for sampling households, shops, garages and other premises in urban areas

Address is selected at random from sampling frame (usually electoral register) as a starting point. Interviewer then given instructions to identify further addresses by taking alternate left- and right-hand turns at road junctions and calling at every nth address (shop, garage etc.)

Advantages:

• May be saving in time
• Bias may be reduced because interviewer has to call at clearly defined addresses - not able to choose

• Characteristics of particular areas (e.g. poor / rich) may mean that sample is not representative
• Open to abuse by interviewer because difficult to check that instructions fully carried out