LESSON 29 - SAMPLING: METHODS OF DETERMINING THE SAMPLE SIZE IN QUANTITATIVE RESEARCH

LESSON 29 - SAMPLING: METHODS OF DETERMINING THE SAMPLE SIZE IN QUANTITATIVE RESEARCH

by Prof. Lydia Wambugu

Humanities, Social Sciences & Thought Science — General & History GPSResearch methodsGPSDQuantitative research methods
🎙 Prof. Lydia Wambugu 👥 29K 📅 June 4, 2021 ⏱ 21 min 👁 24K 📄 tutorial 🧭 2026-08-17
Available in: English (current) Français

Keywords

sample sizequantitative researchsamplingconfidence levelmargin of error

Summary

This lesson from the Research Methods Class with Prof. Lydia Wambugu focuses on methods for determining sample size in quantitative research. It begins by recapping key sampling concepts from the previous lesson, such as sample, population, and sampling error. The instructor then outlines five factors to consider when determining sample size: type of research, confidence level, level of precision, population size, and non-response rate. Each factor is explained with examples, such as the relationship between confidence level and sample size. The lesson then presents five strategies for determining sample size: using a census for small populations, using a sample size from a similar study, using internet sample size calculators, using published tables like Krejcie and Morgan or Glenn, and using mathematical formulas like Yamane’s. The instructor demonstrates the use of an internet calculator and the Yamane formula with a population of 500, yielding sample sizes of 218 and 222 respectively. The lesson concludes by emphasizing that the last three methods are more scientific than the first two, and previews the next lesson on random sampling techniques.

176 words

Critical Evaluation

Value of the Information & Strength of the Argument

The video provides a clear and structured overview of sample size determination, which is valuable for students and researchers. The argumentation is logical, building from factors to methods, and uses concrete examples to illustrate concepts. However, it does not critically evaluate the methods or discuss their assumptions and limitations, which could lead to oversimplification. The presentation is didactic and accessible, but lacks depth in explaining the statistical underpinnings.

Scientific Rigor, Source Quality, Title Accuracy

The scientific rigor is moderate: the content is accurate but not deeply sourced. The instructor mentions Krejcie and Morgan, Glenn, and Yamane, but does not provide citations or references. The title accurately reflects the content. The description includes links to the instructor’s social media and course, but no direct references to academic sources. The video is a tutorial, so it does not claim to present original research, but it could benefit from citing the original works for the tables and formulas.

164 words

Title / Content Match

The title accurately reflects the content, which focuses on methods for determining sample size in quantitative research.

Quality & Reliability

7/10

The content is a structured tutorial on sample size determination, presenting standard methods and formulas. It is accurate but lacks citations to primary sources and does not discuss limitations or alternatives in depth.

Key Moments

Markers derived by PSI from the transcript: the creator did not define chapters.

Cited Sources

  • Research Methods Course — Full course access
  • YouTube Channel — Subscribe for more lessons
  • Facebook — Follow on social media
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  • WhatsApp — Live chat support

Concurring Sources

Contribution & Novelties

The video provides a concise and practical guide to sample size determination, which is useful for students and researchers. It consolidates common methods and factors into a single lesson, making it a convenient reference. However, it does not offer novel insights or advanced techniques.

Pour aller plus loin :

75 words

Radar Profile

The radar profile shows high scores in quantity of information and reliability, but lower in technical depth and novelty. This indicates a solid introductory tutorial that is accurate but not advanced.

Reliability 7/10