The authors of the chapter have addressed only the statistical and cost related problems of the optimal dual frame mixture and corresponding costs. First they represented dual frame designs and three ways of multiple frame research literature. In addition we are informed about the analytic solution of the mixture parameter. They have studied how to mix the mobile and fixed telephone subsamples in dual frame surveys. The authors had found that if the true population value is in the middle, it is optimal to take 50% of each subsample to form the population estimate. But if there is no difference among them, only the fixed telephone should be used, because it is cheaper.
COBISS.SI-ID: 31170141
Authors have first represented methodological issues of telephone surveys. The trends show that telephone surveying remains one the most popular mode to collect data, because it is simple to obtain probability samples of general population, with acceptable response and coverage rates. The problem is that the number of households without fixed phone is increasing, but these household have at least one mobile phone. But in the case of mobile phone surveys the most inconvenient are increased costs. According to that mixed mode surveys are one of the most promising answers of modern survey methodology to the key problems. The authors have first showed how to analytically develop the product equation and compute the exact optimal mixture for a given setting. The second example illustrates how to perform the postsurvey evaluation for mixed-mode surveys, where costs and errors are treated simultaneously.
COBISS.SI-ID: 31854429
The authors of the paper presented an alternative approach to identifying the ties between authors of posts. First they have discussed different approaches to measuring communication networks in Usenet and web forums. In the next section ties and networks based on web forum data were defined. In the empirical part they have considered the FDVjevka web forum. Authors of the paper are trying to create pseudo reply-to network measures, which are based on spatial and temporal patterns of posts in the web forum threads.
COBISS.SI-ID: 30132573