Sample Design and Analysis

Researchers often use sample survey methodology to obtain information about a large aggregate or population by selecting and measuring a sample from that population. Due to the variability of characteristics among items in the population, researchers apply scientific sample designs in the sample selection process to reduce the risk of a distorted view of the population, and they make inferences about the population based on the information from the sample survey data. In order to make statistically valid inferences for the population, they must incorporate the sample design in the data analysis.

Much of FPIL's work uses the following sampling methods:

• simple random sampling

• unrestricted random sampling (with replacement)

• systematic

• sequential

• selection probability proportional to size (PPS)

Computer-Assisted telephone Interviewing (CATI)

Now FPIL has more than 30 stations for the CATI.

-All telephone interviews are made in office and controlled on the spot by the conductors.
-30% of the coding is checked by the manager in charge of the project and double entry is practiced 100% of the time.

FPIL has adopted the Wincati software. As a computer-assisted telephone interview system software widely used by research companies worldwide, it provides access to a broad range of features:

• Questionnaire authoring and administration

• Sampling and call management

• Quota control

• Call disposition monitoring

• Data coding and editing

• Direct data and label exporting to analysis systems

The telephone interview center of FPIL is also capable of recording the whole interview, enabling clients to check our work at any time, also providing accurate sound information for coding of open-ended questions. What ‘s more, clients can dial in with phone set our CATI center to listen to the interviewing of any station wherever he/she is.