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 Experiment Videos

Sample size and power in psychiatric research.

D L Streiner1

  • 1Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, Ontario.

Canadian Journal of Psychiatry. Revue Canadienne De Psychiatrie
|October 1, 1990
PubMed
Summary

Researchers can control statistical errors by understanding sample size. Insufficient sample size increases the risk of Type II errors, while overly large samples waste resources.

Related Concept Videos

You might also read

Related Articles

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

Sort by
Same author

Objective and subjective vasomotor symptom outcomes in the CBT-Meno randomized controlled trial.

Climacteric : the journal of the International Menopause Society·2020
Same author

Validation of MRI predictors of multiple sclerosis diagnosis in children with acute CNS demyelination.

Multiple sclerosis and related disorders·2015
Same author

Development of a standardized MRI scoring tool for CNS demyelination in children.

AJNR. American journal of neuroradiology·2013
Same author

The trajectory of recovery and the inter-relationships of symptoms, activity and participation in the first year following total hip and knee replacement.

Osteoarthritis and cartilage·2011
Same author

Sore throats in adults: who sees a doctor?

Canadian family physician Medecin de famille canadien·2011
Same author

Quality of life in childhood epilepsy: what is the level of agreement between youth and their parents?

Epilepsy & behavior : E&B·2009

Area of Science:

  • Statistical analysis in research
  • Biostatistics
  • Research methodology

Background:

  • Research conclusions are vulnerable to Type I and Type II errors.
  • Type I errors occur when a true difference is missed, while Type II errors occur when no difference is found due to chance.
  • While Type I error probability is managed by alpha levels, Type II error control often neglects sample size estimation.

Purpose of the Study:

  • To discuss methods for calculating appropriate sample sizes for studies.
  • To explain the consequences of inadequate or excessive sample sizes.
  • To guide readers in evaluating negative findings in research.

Main Methods:

  • Discussion of statistical error types (Type I and Type II).
  • Explanation of sample size calculation techniques.
  • Analysis of the impact of sample size on study outcomes.

Main Results:

  • Small sample sizes increase the risk of Type II errors (false negatives).
  • Large sample sizes can lead to wasted time, money, and effort.
  • Proper sample size estimation is crucial for valid research conclusions.

Conclusions:

  • Researchers must understand and apply sample size calculations to minimize Type II errors.
  • Readers should critically assess sample sizes when interpreting negative research findings.
  • Appropriate sample size is fundamental for the reliability and efficiency of scientific studies.

Related Experiment Videos