J. T. Lessler’s scientific contributions

... It is common that online questionnaires can be prone to such problems, as sampling frame error, no answer error, and response bias (Couper, 2000;Lessler & Kalsbeek, 1992). However, as the target group investigated in this study consisted of consumers who intended to buy traceable food, these consumers had to scan QR codes or entered traceable codes on the web to get traceability information, so they must have been able to use smartphones or other electronic equipment. ...

Reference:

Discussion of Consumers’ Preference for Food Product Traceability Information: Beijing Traceable Tomato Case Study

... This is due, in part, to nonsampling errors. Unlike sampling errors, which result from the conscious choice to collect data from a sample instead of an entire population, nonsampling errors are unintentional and can exist in a number of forms (Lessler and Kalsbeek 1992). If there is a difference between a reported or measured value and the true, unknown value for a survey outcome, the consequence is a form of nonsampling error known as measurement error (or response error). ...

Reference:

Adjusting for Measurement Error and Nonresponse in Physical Activity Surveys: A Simulation Study