how is random sampling different from haphazard sampling
Taher,
In random sampling method, the items in the sample are chosen at random. In other words, each and every item of the universe has an equal chance of being selected in the sample. The items that would be chosen are not pre-planned or predictable. Thus, the selection of items in the sample is purely based on chance or on the concept of probability. Since, the items are chosen randomly, this method avoids personal bias. However, haphazard sampling is one of the nonstatistical technique that deliberately trying to imitate like random method.
In random sampling method, the items in the sample are chosen at random. In other words, each and every item of the universe has an equal chance of being selected in the sample. The items that would be chosen are not pre-planned or predictable. Thus, the selection of items in the sample is purely based on chance or on the concept of probability. Since, the items are chosen randomly, this method avoids personal bias. However, haphazard sampling is one of the nonstatistical technique that deliberately trying to imitate like random method.