We therefore studied the similarity of self-samples and investigator-samples in testing the presence of S. aureus in nares and pharynxes of healthy study subjects in the Netherlands, using random sample order and clear instructions.
While this study attempted to reduce the various biases that can occur in this type of survey, such as selection bias by using a random sample, order bias by scrambling the arrangement of photos to be chosen by volunteers, there are some areas that could not be lessened.
Because the order of sampling can impact the shape of this curve, we computed 1,000 replicate random sample orders and calculated the mean number of unigenes detected after each draw.
This comparison has historically been conducted using a 95% one-sided confidence interval for the 0.95-quantile of the output distribution, which is usually found following the technique of simple random sampling using order statistics (SRS-OS).
In case cohort designs, it is often useful to select subcohort members using an exposure-based stratified random sampling in order to gain statistical efficiency [ 29].
In the first stage, five villages were selected using simple random sampling in order to give equal chance for each village.
A random sample of 75 GPs, from the list of all GPs practising in the canton, was invited to participate by post, using simple random sampling, in order to include 25 GPs in the study (expected participation rate: 33%).
For the two random sampling strategies, in order to maintain the order of magnitude suggested both from SIFT and SURF for the employed collections, we set the number of extracted patches to be a total of 600 per image (i.e. 150 samples per scale).
Fifty patient records were selected from the database as a stratified random sample in order to represent the patient population of our teaching hospital adult ICU.
Therefore every vector is permuted a 100 times and correlated with this random sample in order to test, using the corresponding average and confidence interval, whether or not correlation among any two vectors are indeed more similar that expected by chance alone.
