Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Reliability and Validity01:29

Reliability and Validity

13.3K
Reliability and validity are two important considerations that must be made with any type of data collection. Reliability refers to the ability to consistently produce a given result. In the context of psychological research, this would mean that any instruments or tools used to collect data do so in consistent, reproducible ways.
13.3K
Statistical Analysis: Overview01:11

Statistical Analysis: Overview

11.2K
When we take repeated measurements on the same or replicated samples, we will observe inconsistencies in the magnitude. These inconsistencies are called errors. To categorize and characterize these results and their errors, the researcher can use statistical analysis to determine the quality of the measurements and/or suitability of the methods.
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...
11.2K
Uncertainty in Measurement: Accuracy and Precision03:37

Uncertainty in Measurement: Accuracy and Precision

97.9K
Scientists typically make repeated measurements of a quantity to ensure the quality of their findings and to evaluate both the precision and the accuracy of their results. Measurements are said to be precise if they yield very similar results when repeated in the same manner. A measurement is considered accurate if it yields a result that is very close to the true or the accepted value. Precise values agree with each other; accurate values agree with a true value. 
97.9K
Comparing Experimental Results: Student's t-Test01:09

Comparing Experimental Results: Student's t-Test

3.6K
The t-test is a statistical method used to compare the sample mean with a population mean or compare two means from two data sets. The test statistic is calculated from the standard deviation, mean, and number of measurements in the data set at a selected confidence interval and then compared to a table of critical values at this confidence level. If the test statistic is smaller than the critical value, the null hypothesis is accepted. In this case, we state that the difference between the...
3.6K
Regression Toward the Mean01:52

Regression Toward the Mean

6.6K
Regression toward the mean (“RTM”) is a phenomenon in which extremely high or low values—for example, and individual’s blood pressure at a particular moment—appear closer to a group’s average upon remeasuring. Although this statistical peculiarity is the result of random error and chance, it has been problematic across various medical, scientific, financial and psychological applications. In particular, RTM, if not taken into account, can interfere when...
6.6K
Testing a Claim about Standard Deviation01:19

Testing a Claim about Standard Deviation

2.6K
A complete procedure to test a claim about population standard deviation or population variance is explained here.
The hypothesis testing for the claim of population standard deviation (or variance) requires the data and samples to be random and unbiased. The population distribution also must be normal. There is no specific requirement on the sample size as the estimation is based on the chi-square distribution.
As a first step, the hypothesis (null and alternative) concerning the claim about...
2.6K

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

The Use of Free Weight Squats in Sports: A Narrative Review-Squatting Movements, Adaptation, and Sports Performance: Physiological.

Journal of strength and conditioning research·2024
Same author

Fatigue on the Countermovement Jump Characteristics: Basketball-Related High-Intensity Exercises: Erratum.

Journal of strength and conditioning research·2024
Same author

Effect of Neuromuscular Fatigue on the Countermovement Jump Characteristics: Basketball-Related High-Intensity Exercises.

Journal of strength and conditioning research·2023
Same author

Acute Kinetic and Kinematic Responses to Rest Redistribution With Heavier Loads in Resistance-Trained Men.

Journal of strength and conditioning research·2022
Same author

Acute Physiological and Perceptual Responses to Rest Redistribution With Heavier Loads in Resistance-Trained Men.

Journal of strength and conditioning research·2022
Same author

The Effects of Caffeine on Jumping Performance and Maximal Strength in Female Collegiate Athletes.

Nutrients·2021

Related Experiment Video

Updated: Nov 4, 2025

Isokinetic Robotic Device to Improve Test-Retest and Inter-Rater Reliability for Stretch Reflex Measurements in Stroke Patients with Spasticity
08:40

Isokinetic Robotic Device to Improve Test-Retest and Inter-Rater Reliability for Stretch Reflex Measurements in Stroke Patients with Spasticity

Published on: June 12, 2019

7.6K

A Technical Report on Reliability Measurement in Asymmetry Studies.

Chris A Bailey1, Kimitake Sato2, Timothy C McInnis3

  • 1Department of Kinesiology, Health Promotion, and Recreation, University of North Texas, Denton, Texas.

Journal of Strength and Conditioning Research
|May 24, 2021
PubMed
Summary
This summary is machine-generated.

Reliability in sport asymmetry studies is often overestimated. Evaluating asymmetry as a vector, not just scalar, improves accuracy and avoids biased results in performance assessments.

More Related Videos

Measurement of Dynamic Scapular Kinematics Using an Acromion Marker Cluster to Minimize Skin Movement Artifact
10:07

Measurement of Dynamic Scapular Kinematics Using an Acromion Marker Cluster to Minimize Skin Movement Artifact

Published on: February 10, 2015

19.6K
Assessment of Child Anthropometry in a Large Epidemiologic Study
09:36

Assessment of Child Anthropometry in a Large Epidemiologic Study

Published on: February 2, 2017

27.4K

Related Experiment Videos

Last Updated: Nov 4, 2025

Isokinetic Robotic Device to Improve Test-Retest and Inter-Rater Reliability for Stretch Reflex Measurements in Stroke Patients with Spasticity
08:40

Isokinetic Robotic Device to Improve Test-Retest and Inter-Rater Reliability for Stretch Reflex Measurements in Stroke Patients with Spasticity

Published on: June 12, 2019

7.6K
Measurement of Dynamic Scapular Kinematics Using an Acromion Marker Cluster to Minimize Skin Movement Artifact
10:07

Measurement of Dynamic Scapular Kinematics Using an Acromion Marker Cluster to Minimize Skin Movement Artifact

Published on: February 10, 2015

19.6K
Assessment of Child Anthropometry in a Large Epidemiologic Study
09:36

Assessment of Child Anthropometry in a Large Epidemiologic Study

Published on: February 2, 2017

27.4K

Area of Science:

  • Sport Science
  • Biomechanics
  • Performance Analysis

Background:

  • Current literature on sport performance asymmetry may be unreliable due to flawed reliability testing.
  • Evaluating reliability after asymmetry metric production can lead to biased results and misinformed decisions.

Purpose of the Study:

  • To evaluate the reliability of asymmetry measurements in countermovement jumps (CMJs).
  • To compare reliability before and after producing scalar and vector asymmetry metrics.
  • To analyze how quantification methods affect reliability and inform decision-making.

Main Methods:

  • Thirteen collegiate baseball players performed bilateral countermovement jumps on two force plates.
  • Symmetry index (SI) scores were calculated as scalar (magnitude) and vector (magnitude and direction) quantities.
  • Relative and absolute reliability were assessed for peak force (PF), scalar PF SI, and vector PF SI.

Main Results:

  • Reliability measures on constituent force-time variables were more favorable (CVs 10.4–15.7%) than on asymmetry measures (CVs 63.2–1,497.1%).
  • Reliability differs significantly based on whether asymmetry is quantified as a scalar or vector.
  • Vector quantification of asymmetry is recommended for improved reliability due to consideration of both magnitude and direction.

Conclusions:

  • Inadequate reliability evaluation in asymmetry studies leads to biased findings.
  • Practitioners must exercise caution with asymmetry assessment results, as they may not be as reliable as commonly assumed.
  • Quantifying asymmetry as a vector is crucial for accurate and reliable performance analysis in sports.