Learning about statistics is a lot like learning about science: the learning is more meaningful if you can actively explore. This series in Advances in Physiology Education provides an opportunity to do just that: we will investigate basic concepts in statistics using the free software package R. Because this series uses R solely as a vehicle with which to explore basic concepts in statistics, ...

BACKGROUND Previous studies have reported the effects of statistics of luminance distribution on visual freshness perception using pictures which included the degradation process of food samples. However, these studies did not examine the effect of individual differences between the same kinds of food. Here we elucidate whether luminance distribution would continue to have a significant effect ...

OBJECTIVE It is standard practice to clean the skin using a non-alcohol-containing swab before forensic blood alcohol sampling, because of the belief that the use of an alcohol-containing swab will contaminate the sample. The present study aimed to determine whether cleaning the skin with 70% isopropyl alcohol swabs, before venepuncture, alters measured blood alcohol level (BAL). METHODS Volu...

Significance testing in comparisons is based on Student's t-tests for pairs and analysis of variance (ANOVA) for simultaneous comparison of several procedures. Access to the average, standard deviation and number of observations is sufficient for calculating the significance of differences using the Student's tests and the ANOVA. Once an ANOVA has been calculated, analysis of variance component...

background: relaxation-training, as an anxiety-reducer intervention, plays an important role in fetal health. the present study aimed to analyze the effect of maternal relaxation on stress test (nst), basal fetal heart rate, and number of fetal heart accelerations. methods: in this randomized controlled trial, 84 pregnant women were randomly divided into two groups of teaching relaxation and co...

Standard deviation (SD) and standard error (SE) are quietly but extensively used in biomedical publications. These terms and notations are used as descriptive statistics (summarizing numerical data), and they are used as inferential statistics (estimating population parameters from samples). I review the use and misuse of SD and SE in several authoritative medical journals and make suggestions ...

Jitter is a variation in a waveform’s timing. The timing variation of the period, duty cycle, frequency, etc. can be measured and compared to an average of multiple periods, or can be measured as a variation from one period to the next. A jitter measurement result will typically consist of a count of the number of periods evaluated over the selected time interval, a measurement of the highest v...

In digital, computerized analytical measurement raw data signal samples are collected at a given frequency. In two-dimensional analytical methods the analytical information is produced by different algorithms, which can be the integrated peak area, the height of the peak, or the extreme values of the measured signal (for example the retention time in chromatography). The analytical information ...