The pervasiveness of the internet has led to online research, and in particular online research undertaken via non-probability online panels, to become the dominant mode of sampling and data collection used by the Australian market and social research industry.

There are broad based concerns that the rapid increase in the use of non-probability online panels in Australia has not been accompanied by an informed debate regarding the advantages and disadvantages of probability and non-probability surveys.

Thus, the 2015 Australian Online Panels Benchmarking Study was undertaken to inform this debate and report on the findings from a single national questionnaire administered across three different probability samples and five different non-probability online panels.

This study enables us to investigate whether Australian surveys using probability-sampling methods produce different results in terms of accuracy, relative to independent population benchmarks, than Australian online surveys relying upon non-probability sampling methods. In doing so we build on similar international research in this area. We discuss our findings as they relate to Coverage Error, Non-response Error, Adjustment Error, and Measurement Error.