Statistics Department

Design and Selection of a Probability Sample

The SRC can provide clients with estimates of the scale and cost of surveys assuming various sample sizes and with different modes of data collection. Given the study's precision requirements, sample sizes can be computed to provide statistically reliable estimates. The SRC can offer advice on advantages and disadvantages of using various sample designs, such as the use of stratification, for a study.

Questionnaire Development

With more than 25 years experience in questionnaire development, the staff of the SRC works closely with clients to generate a questionare that meets project objectives while minimizing bias and measurement error.

Data Collection

The SRC uses both mail and the Internet to conduct surveys.  The SRC has conducted research comparing Web and mail surveys since 2002.  This research along with participation at national survey meetings provides SRC staff information to recommend the best survey mode for survey data collection.  The SRC can provide input on the advantages and disadvantages of survey delivery mode for different populations. 

Data Editing, Coding, and Entry

A data entry program used specifically for survey data is utilized which provides efficient and accurate data entry and verification. Editing checks are done on all data files to minimize coding errors. Statistical weights are applied when necessary in the analysis to account for the survey design features. Strict confidentiality is maintained for all respondents.

Data Analysis and Summary Reports

Statistical analyses are selected which are appropriate for the sampling design and objectives of the survey. Analytical adjustments for non-response bias are also evaluated. A summary report detailing the survey procedures and results is provided for each survey.