SAMPLING ERROR AND SAMPLING BIAS:
Sampling error may be deiined as the difference between data obtained from random sample and data obtained from entire population. Error may be contained In sample data even when most careful random sampling procedure has been used in obtaining the sample sampling error is not under researchers control. It is caused by the chance variations that may occur when the sample is chosen to represent a population value.
Sampling bias occurs when researcher does not carefully select samples. Non- probability sampling methods are subjecrs tc sampling bias. Sampling error occurs by chance and researcher causes sanlpling bias.