Related Experiment Video
Updated: Aug 7, 2026

Doppler Ultrasound-Based Leg Blood Flow Assessment During Single-Leg Knee-Extensor Exercise in an Uncontrolled Setting
Published on: December 15, 2023
Reliability in the context of the experiment: A commentary on two articles by Birkimer and Brown
1Reidsville City Schools.
Abstract:
Two sources of variability must each be considered when examining change in level between two sets of data obtained by human observers; namely, variance within data sets (phases) and variability attributed to each data point (reliability). Birkimer and Brown (1979a, 1979b) have suggested that both chance levels and disagreement bands be considered in examining observer reliability and have made both methods more accessible to researchers. By clarifying and extending Birkimer and Brown's papers, a system is developed using observer agreement to determine the data point variability and thus to check the adequacy of obtained data within the experimental context.
Related Concept Videos
Reliability and Validity
Naturalistic Observations
Uncertainty in Measurement: Accuracy and Precision
Statistical Analysis: Overview
One of the most commonly used statistical quantifiers is the mean, which is the ratio between the sum of the numerical values of all results and the...
Random and Systematic Errors
Accuracy and Errors in Hypothesis Testing
In hypothesis testing, the probability of making a Type I error, denoted as α, is commonly set at 0.05. This significance level indicates a 5% chance...

