Search research articles

ABOUT JoVE

Overview Leadership Blog JoVE Help Center

AUTHORS

Publishing Process Editorial Board Scope & Policies Peer Review FAQ Submit

LIBRARIANS

Testimonials Subscriptions Access Resources Library Advisory Board FAQ

RESEARCH

JoVE Journal Methods Collections JoVE Encyclopedia of Experiments Archive

EDUCATION

JoVE Core JoVE Business JoVE Science Education JoVE Lab Manual Faculty Resource Center Faculty Site

Terms & Conditions of Use

Related Concept Videos

Group Design

Group Design

The most basic experimental design involves two groups: the experimental group and the control group. The two groups are designed to be the same except for one difference— experimental manipulation. The experimental group gets the experimental manipulation—that is, the treatment or variable being tested—and the control group does not. Since experimental manipulation is the only difference between the experimental and control groups, we can be sure that any differences between the two are due to...

Stratified Sampling Method

Stratified Sampling Method

Sampling is a technique to select a portion (or subset) of the larger population and study that portion (the sample) to gain information about the population. The sampling method ensures that samples are drawn without bias and accurately represent the population. Because measuring the entire population in a study is not practical, researchers use samples to represent the population of interest.
To choose a stratified sample, divide the population into groups called strata and then take a...

Random Sampling Method

Random Sampling Method

Sampling is a technique to select a portion (or subset) of the larger population and study that portion (the sample) to gain information about the population. Data are the result of sampling from a population. The sampling method ensures that samples are drawn without bias and accurately represent the population. Because measuring the entire population in a study is not practical, researchers use samples to represent the population of interest. Among the various sampling methods used by...

Randomized Experiments

Randomized Experiments

The randomization process involves assigning study participants randomly to experimental or control groups based on their probability of being equally assigned. Randomization is meant to eliminate selection bias and balance known and unknown confounding factors so that the control group is similar to the treatment group as much as possible. A computer program and a random number generator can be used to assign participants to groups in a way that minimizes bias.
Simple randomization
Simple...

Bioequivalence Experimental Study Designs: Completely Randomized and Randomized Block Designs

Bioequivalence Experimental Study Designs: Completely Randomized and Randomized Block Designs

Bioequivalence experimental study designs are crucial methodologies used in evaluating and comparing the bioavailability of different drug products. These designs are categorized into various types: completely randomized, randomized block, repeated measures, cross and carry-over, and Latin square designs.Completely randomized designs involve randomly allocating treatments to all subjects participating in the experiment. This allocation is achieved by assigning unique random numbers to subjects...

Bioequivalence Experimental Study Designs: Repeated Measures, Cross-Over, Carry-Over, and Latin Square Designs

Bioequivalence Experimental Study Designs: Repeated Measures, Cross-Over, Carry-Over, and Latin Square Designs

Bioequivalence experimental study designs play a pivotal role in testing the effectiveness of various treatments. Key among these are the repeated measures, cross-over, carry-over, and Latin square designs. In the repeated measures design, each subject receives all treatments, allowing for temporal comparisons. This type of design is useful in reducing variability but requires careful planning to avoid bias.The cross-over design, an economical method, involves sequential administration of...

You might also read

Related Articles

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

Sort by

Same author

Paclitaxel-coated stents to prevent hyperplastic proliferation of ureteral tissue: from in vitro to in vivo.

Urolithiasis·2018

Same author

[Visual analysis for an early detection of diabetic neuropathy].

Klinische Monatsblatter fur Augenheilkunde·2014

Same author

[What Makes Happy Doctors? Job Satisfaction of General Practitioners in Mecklenburg-Western Pomerania - a Representative Cross-sectional Study].

Gesundheitswesen (Bundesverband der Arzte des Offentlichen Gesundheitsdienstes (Germany))·2014

Same author

Influence of local hemostatic and antiplatelet agents on the incidence of bleeding complications in carotid endarterectomies.

Clinical hemorheology and microcirculation·2014

Same author

Pneumocystis jirovecii colonisation in HIV-positive and HIV-negative subjects in Cameroon.

Tropical medicine & international health : TM & IH·2014

Same author

Accompanying DCIS in breast cancer patients with invasive ductal carcinoma is predictive of improved local recurrence-free survival.

Breast (Edinburgh, Scotland)·2014

Search research articles

Related Experiment Video

Updated: Jun 22, 2026

Barnes Maze Testing Strategies with Small and Large Rodent Models

Barnes Maze Testing Strategies with Small and Large Rodent Models

Published on: February 27, 2014

An alternative proposal for "Mixed randomization" by Schulz and Grimes.

¹University of Rostock, School of Medicine, Department of Medical Informatics and Biometry, Germany. guenther.kundt@medizin.uni-rostock.de

Methods of Information in Medicine

|December 14, 2005

Summary

This summary is machine-generated.

Permuted-block randomization with a large block size offers similar unpredictability to "Mixed randomization" while improving balance in clinical trials. This approach is recommended for its feasibility and performance.

More Related Videos

Experimental Protocol for Manipulating Plant-induced Soil Heterogeneity

Experimental Protocol for Manipulating Plant-induced Soil Heterogeneity

Published on: March 13, 2014

Acupoint Catgut Embedding Therapy in Traditional Chinese Medicine for Managing Allergic Rhinitis

Acupoint Catgut Embedding Therapy in Traditional Chinese Medicine for Managing Allergic Rhinitis

Published on: December 20, 2024

Related Experiment Videos

Last Updated: Jun 22, 2026

Barnes Maze Testing Strategies with Small and Large Rodent Models

Barnes Maze Testing Strategies with Small and Large Rodent Models

Published on: February 27, 2014

Experimental Protocol for Manipulating Plant-induced Soil Heterogeneity

Experimental Protocol for Manipulating Plant-induced Soil Heterogeneity

Published on: March 13, 2014

Acupoint Catgut Embedding Therapy in Traditional Chinese Medicine for Managing Allergic Rhinitis

Acupoint Catgut Embedding Therapy in Traditional Chinese Medicine for Managing Allergic Rhinitis

Published on: December 20, 2024

Area of Science:

Clinical Trials Methodology
Biostatistics
Research Design

Background:

Randomization is crucial in clinical trials to prevent bias.
Permuted-block randomization can compromise unpredictability when forcing equal group sizes.
Schulz and Grimes proposed
Mixed randomization
as a more complex alternative.

Purpose of the Study:

To develop a randomization model simpler than
Mixed randomization
with comparable unpredictability and balance.
To evaluate the performance of randomization techniques in clinical trial design.

Main Methods:

Analysis of
Mixed randomization
for unpredictability and balancing power.
Comparison with permuted-block randomization using a large block size in worst-case scenarios.
Application of the Blackwell-Hodges model to assess treatment assignment unpredictability.

Main Results:

Permuted-block randomization (block size b = 36) demonstrated performance similar to
Mixed randomization
in terms of unpredictability.
Permuted-block randomization showed superior balancing power compared to
Mixed randomization
.

Conclusions:

While Schulz and Grimes' findings on sample size are important,
Mixed randomization
is overly complex and less feasible.
Permuted-block randomization with an optimally chosen large block size is recommended as a practical and effective restricted randomization procedure.