The effectiveness of increasing sample size to mitigate the influence of population characteristics in haphazard sampling

Over 40 years ago both Deming (1954) and Arkin (1957) expressed concerns th at the composition of samples chosen through haphazard selection may be unr epresentative due to the presence of unintended selection biases. To mitiga te this problem some experts in the field of audit sampling recommend incre asing sample sizes by up to 100 percent when utilizing haphazard selection. To examine the effectiveness of this recommendation 142 participants selec ted haphazard samples from two populations. The compositions of these sampl es were then analyzed to determine if certain population elements were over represented, and if the extent of overrepresentation declined as sample siz e increased. Analyses disclosed that certain population elements were overrepresented in the samples. Also, increasing sample size produced no statistically signif icant change in the composition of samples from one population, while in th e second population increasing the sample size produced a statistically sig nificant but minor reduction in overrepresentation. These results suggest t hat individuals may be incapable of complying with audit guidelines that ha phazard sample selections be made without regard to the observable physical features of population elements and cast doubt on the effectiveness of usi ng larger sample sizes to mitigate the problem. Given these findings, stand ard-setting bodies should reconsider the conditions under which haphazard s ampling is sanctioned as a reliable audit tool.