Editing Sampling (statistics) (section)

===Panel sampling===
'''Panel sampling''' is the method of first selecting a group of participants through a random sampling method and then asking that group for (potentially the same) information several times over a period of time. Therefore, each participant is interviewed at two or more time points; each period of data collection is called a "wave". The method was developed by sociologist [[Paul Lazarsfeld]] in 1938 as a means of studying [[political campaign]]s.<ref>Lazarsfeld, P., & Fiske, M. (1938). The" panel" as a new tool for measuring opinion. The Public Opinion Quarterly, 2(4), 596–612.</ref> This [[longitudinal study|longitudinal]] sampling-method allows estimates of changes in the population, for example with regard to chronic illness to job stress to weekly food expenditures. Panel sampling can also be used to inform researchers about within-person health changes due to age or to help explain changes in continuous dependent variables such as spousal interaction.<ref name="SM" >
Groves, et alia. ''Survey Methodology''
</ref> There have been several proposed methods of analyzing [[panel data]], including [[MANOVA]], [[growth curve (statistics)|growth curves]], and [[structural equation modeling]] with lagged effects.