Some authors try to use the same type of estimator more than once to find the
estimate of the population parameter. In literature, these estimators are called chain estimators.
Statisticians see that the estimator having the power of alpha gets more efficient than the
estimators without power. By this realization, popularity of the chain estimators has increased.
In Chapter 4, the studies on this kind of estimators are reviewed such as Srivastava (1967), Rao
(1991), Garcia and Cebrain (1996), Kadilar and Cingi (2003), Abu Dayeh et al. (2003), Chandra
and Singh (2005), Turgut and Cingi (2008).
