Jove
Visualize
联系我们
JoVE
x logofacebook logolinkedin logoyoutube logo
关于 JoVE
概览领导团队博客JoVE 帮助中心
作者
出版流程编辑委员会范围与政策同行评审常见问题投稿
图书馆员
用户评价订阅访问资源图书馆顾问委员会常见问题
研究
JoVE JournalMethods CollectionsJoVE Encyclopedia of Experiments存档
教育
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab Manual教师资源中心教师网站
使用条款与条件
隐私政策
政策

相关概念视频

Cluster Sampling Method01:20

Cluster Sampling Method

11.6K
Appropriate sampling methods ensure 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 cluster sample, divide the population into clusters (groups) and then randomly select some of the clusters. All the members from these clusters are in the cluster sample. For example, if you randomly sample four departments from your...
11.6K
Sampling Plans01:23

Sampling Plans

162
Sampling is a crucial step in analytical chemistry, allowing researchers to collect representative data from a large population. Common sampling methods include random, judgmental, systematic, stratified, and cluster sampling.
Random sampling is a method where each member of the population has an equal chance of being selected for the sample. It involves selecting individuals randomly, often using random number generators or lottery-type methods. For example, when analyzing the properties of a...
162
Randomized Experiments01:13

Randomized Experiments

6.6K
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...
6.6K
Longitudinal Research02:20

Longitudinal Research

11.8K
Sometimes we want to see how people change over time, as in studies of human development and lifespan. When we test the same group of individuals repeatedly over an extended period of time, we are conducting longitudinal research. Longitudinal research is a research design in which data-gathering is administered repeatedly over an extended period of time. For example, we may survey a group of individuals about their dietary habits at age 20, retest them a decade later at age 30, and then again...
11.8K
Sample Size Calculation01:19

Sample Size Calculation

3.2K
Knowledge of the sample size is the first requirement to conduct random sampling or an experiment. The sample size is the total number of units, observations, or groups (in some cases) used to get the data to estimate a population parameter. As the name suggests, the sample size is that of the sample drawn from the population and differs from the population size.
The sample size for the given experiment or sampling effort is fundamental to any study design. Sample size decides the number of...
3.2K
One-Way ANOVA: Unequal Sample Sizes01:15

One-Way ANOVA: Unequal Sample Sizes

5.7K
One-way ANOVA can be performed on three or more samples of unequal sizes. However, calculations get complicated when sample sizes are not always the same. So, while performing ANOVA with unequal samples size, the following equation is used:
5.7K

您也可能阅读

相关文章

通过共同作者、期刊和引用图与本文相关的文章。

排序
Same author

Community and Academic Synergy for Cancer Survivorship Care Delivery Enhancement (Project CASCADE): a study protocol for a pragmatic, stepped-wedge, cluster-randomized trial in Texas primary care community health centers.

BMC primary care·2025
Same author

Developing eHealth Interventions to Improve Diabetes Management in Emerging Adulthood: Qualitative Formative Study.

JMIR formative research·2025
Same author

A framework for testing non-inferiority in a three-arm, sequential, multiple assignment randomized trial.

Statistical methods in medical research·2024
Same author

Survivorship Care for Women Living With Ovarian Cancer: Protocol for a Randomized Controlled Trial.

JMIR research protocols·2024
Same author

Asthma and Technology in Emerging African American Adults (The ATHENA Project): Protocol for a Trial Using the Multiphase Optimization Strategy Framework.

JMIR research protocols·2022
Same author

Statistical power and sample size requirements to detect an intervention by time interaction in four-level longitudinal cluster randomized trials.

Statistics in medicine·2022

相关实验视频

Updated: May 21, 2025

Sampling Soils in a Heterogeneous Research Plot
07:11

Sampling Soils in a Heterogeneous Research Plot

Published on: January 7, 2019

34.4K

在四级纵向集群随机试验中的样本大小确定,随机倾斜率随机.

Priyanka Majumder1, Siuli Mukhopadhyay2,3, Bo Wang4

  • 1School of Data Science, Indian Institute of Science Education and Research, Thiruvananthapuram, Kerala, India.

Statistical methods in medical research
|March 20, 2025
PubMed
概括
此摘要是机器生成的。

确定四级纵向集群随机试验 (CRT) 的样本大小至关重要. 本研究提供了样本大小计算和最佳分配的方法,对干预研究中的消耗和成本进行了核算.

关键词:
纵向集群随机临床试验随机临床试验磨损 磨损 磨损 磨损 是一种四个级别的数据数据.时间相互作用的干预.混合效应模型的混合效应模型.最优的分配分配最优的分配.权力,权力,权力,权力.样本的大小 样本大小

更多相关视频

Automatic Image Processing to Determine the Community Size Structure of Riverine Macroinvertebrates
08:56

Automatic Image Processing to Determine the Community Size Structure of Riverine Macroinvertebrates

Published on: January 13, 2023

2.1K
Problem-Solving Before Instruction PS-I: A Protocol for Assessment and Intervention in Students with Different Abilities
10:26

Problem-Solving Before Instruction PS-I: A Protocol for Assessment and Intervention in Students with Different Abilities

Published on: September 11, 2021

3.8K

相关实验视频

Last Updated: May 21, 2025

Sampling Soils in a Heterogeneous Research Plot
07:11

Sampling Soils in a Heterogeneous Research Plot

Published on: January 7, 2019

34.4K
Automatic Image Processing to Determine the Community Size Structure of Riverine Macroinvertebrates
08:56

Automatic Image Processing to Determine the Community Size Structure of Riverine Macroinvertebrates

Published on: January 13, 2023

2.1K
Problem-Solving Before Instruction PS-I: A Protocol for Assessment and Intervention in Students with Different Abilities
10:26

Problem-Solving Before Instruction PS-I: A Protocol for Assessment and Intervention in Students with Different Abilities

Published on: September 11, 2021

3.8K

科学领域:

  • 生物统计学 生物统计学
  • 医疗保健服务研究 医疗服务研究
  • 干预科学 干预科学

背景情况:

  • 集群或组随机试验 (CRT) 广泛用于评估行为和系统级干预措施.
  • 准确的样本大小确定在CRT的设计阶段至关重要,以确保足够的统计能力.
  • 具有多个嵌套级别的纵向CRT为样本大小估计带来了独特的统计挑战.

研究的目的:

  • 开发用于在四级纵向CRT中确定样本大小的方法.
  • 通过模拟逐次干预的时间相互作用来检测随时间推移的干预效应.
  • 提供最佳分配的指导,考虑到消耗和成本限制.

主要方法:

  • 使用随机截取和随机斜率混合效应线性回归模型.
  • 每个级别的功率函数和样本大小的衍生闭式表达式.
  • 研究了固定与随机斜率模型对样本大小的影响,当受试者之间的变化显著时.
  • 评估了在四级CRT中忽视集群级别的后果.

主要成果:

  • 在复杂的四级纵向CRT中提供了样本大小计算的统计框架.
  • 证明了最佳主题分配的方法,考虑到诸如消耗和成本等实际约束.
  • 强调考虑随机斜率和所有集群水平对于准确的样本大小确定的重要性.
  • 用现实世界的艾滋病毒预防研究来说明拟议方法的应用.

结论:

  • 该研究提供了一个强大的方法,用于在四级纵向CRT中确定样本大小.
  • 准确的样本大小规划对于成功评估复杂干预措施至关重要.
  • 这些发现强调了需要先进的统计模型,以考虑CRT设计中的层次结构和纵向数据.