Convenience, Haphazard or Accidental sampling - members of the population are chosen based on their relative ease of access.

Nonprobability sampling methods include accidental sampling, quota sampling and purposive sampling.

Dr Jan Visman was an accidental sampling expert because his true calling was coal processing but he became interested in sampling because of his need to understand this process.

For example, interviewers might be tempted to interview those people in the street who look most helpful, or may choose to use accidental sampling to question those closest to them, for time-keeping sake.

Accidental sampling (sometimes known as grab, convenience or opportunity sampling) is a type of nonprobability sampling which involves the sample being drawn from that part of the population which is close to hand.

To sample friends, co-workers, or shoppers at a single mall, are all examples of convenience sampling.

This is considered a better method than convenience sampling, as it attempts to ensure different strata are properly represented.

Conversely, the impossibility of random sampling sometimes necessitates nonprobability sampling, such as convenience sampling or snowball sampling.

(Note, however, that there are some errors in the mathematical calculations done in the study, and the study is statistically invalid as it uses the convenience sampling method.)

'Convenience sampling' (sometimes known as 'grab' or 'opportunity sampling') is a type of nonprobability sampling which involves the sample being drawn from that part of the population which is close to hand.

Sampling methods may be either 'random' (random sampling, systematic sampling, stratified sampling, cluster sampling) or non-random/nonprobability (convenience sampling, purposive sampling, snowball sampling).

In addition to grab sampling, CMDL plans to conduct continuous measurements of CO beside the flask equipment on selected flights.

This includes in-situ sediment grab sampling, the use of a dredge, trawl net, visual imagery or surveys using Remotely Operated Vehicles (ROVs).

The copper mine is of Volcanogenic massive sulfide ore deposit (VMS), modern exploration was conducted during 1966-1972, consisting of mapping, trench and surface grab sampling and analysis.

On the recent excursion, a shakedown cruise for the researchers, Dr. Robert M. Cerrato, a shellfish biologist and associate professor at the marine sciences center, used a trap-like metal grab sampling device to haul up bay-bottom swatches.

Collecting such data over even a small site such as this one requires considerable resources and will probably cause a gap of several days to allow data processing between the first field days and the grab sampling events (It is this delay that precludes, or reduces, the value of studying transient events in hydrodynamically energetic areas).

'Convenience sampling' (sometimes known as 'grab' or 'opportunity sampling') is a type of nonprobability sampling which involves the sample being drawn from that part of the population which is close to hand.