Did you know you can calculate the exact sample size you need before you even start your study? A sample size calculation — also called a power analysis — helps you determine the optimal number of observations for your statistical analysis. It ensures your study is large enough to detect meaningful effects, but not so large that you waste resources.
Key advantages of performing a power analysis:
✔️ Avoid underpowered studies that might miss real effects
✔️ Save time and costs by avoiding unnecessarily large samples
✔️ Tailor your sample size to the effect size you care about detecting
✔️ Choose your desired confidence level and statistical power for robust results
✔️ Works for a wide range of statistical tests, from t‑tests to ANOVA and regression
✔️ Supported by many free R packages, such as pwr
The image shows on the left side how the required sample size changes depending on the expected effect size — smaller effects require much larger samples. On the right side, you see an example of a calculated sample size for comparing two groups using a t-test, showing exactly how many participants are needed per group for the desired confidence level and statistical power.
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The central limit theorem (CLT) is a fundamental concept in statistics, with wide-ranging applications. It states that the distribution of sample means approximates a Gaussian distribution (normal distribution) as the sample size grows, regardless of the population's original distribution. This is crucial for making inferences about populations based on sample data.
Understanding the CLT can greatly enhance your data analysis skills, providing a solid foundation for hypothesis testing and confidence interval estimation. However, it does have some limitations:
❌ Sample Size: The CLT requires a sufficiently large sample size to be effective. Small samples may not produce accurate results.
❌ Independence: The samples must be independent. Dependencies among data points can skew results.
❌ Identical Distribution: Samples must come from the same distribution. Note: This applies to the classical CLT (Lindeberg-Levy), but newer versions like Lyapunov or Lindeberg-Feller relax this condition.
Despite these disadvantages, the CLT remains incredibly useful. Here's why:
✔️ Universality: It applies to a wide range of distributions, making it versatile for various data sets.
✔️ Predictability: With a large enough sample size, predictions about population parameters become more accurate.
✔️ Simplicity: It simplifies complex problems, allowing statisticians and data scientists to use normal distribution properties for analysis.
The attached visualization is based on a Wikipedia image (link: https://t.co/ZgJKHcN1cS) that illustrates how, regardless of the population distribution, the sampling distribution tends towards a Gaussian shape. The dispersion is determined by the central limit theorem, showcasing its robust applicability.
By leveraging the power of the central limit theorem, you can enhance your analytical capabilities and make more reliable decisions based on sample data.
To explain this topic in further detail, I collaborated with Micha Gengenbach to create a comprehensive tutorial: https://t.co/i5eZUmpZ98
Want to take a closer look at statistics and R programming? Consider my online course, "Statistical Methods in R." See this link for additional information: https://t.co/7YQCRDKSPO
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📌 El p-valor es uno de los elementos más malinterpretados de la estadística. Y aunque lo usamos a diario… muchos no entienden bien qué significa ni cómo se debe usar.
Y eso tiene consecuencias: decisiones mal tomadas, resultados sobreinterpretados y modelos que no funcionan.😱
🚨 | Un estudio alemán muestra, por primera vez, que las ratas capturan murciélagos en pleno vuelo, lo que podría permitir que patógenos de murciélagos como los coronavirus y los paramixovirus se transmitan a los roedores, cambiando los patrones de enfermedades y aumentando los riesgos de transmisión a "humanos y animales domésticos".
Exciting news for #QGIS users! The "Google Earth Engine Plugin for QGIS" is now updated with new no-code tools that allow you to download and use #EarthEngine datasets in QGIS easily. Check out my newly contributed tutorials for the latest plugin (1/n) 👇
Les dejamos un trabajo pequeño (y diferente), pero lleno de cariño por Quininí, su gente y su biodiversidad.
Cómo se relacionan ranas, lagartos, serpientes, café y gente? Todo aquí 👇🏾👇🏾👇🏾
Un estudio del MIT revela que usar asistentes de IA para escribir reduce la conectividad cerebral y el rendimiento cognitivo en comparación con usar solo el cerebro o Google.
⚠️El uso de IA generaría "deuda cognitiva": un alto costo a largo plazo por usar "atajos mentales" hoy.
"La Corte no prohibió los planes que ofrecen aplicaciones que no gastan datos; lo que decidió fue que las empresas deben permitir que la gente elija cuáles aplicaciones quiere usar": @AnaBejaranoRG#InternetGratis
https://t.co/0hnbdiiK12
"The ‘silent’ half: diversity, function and the critical knowledge gap on female frog vocalizations" –Such cool work! Super proud of these three #HERpers latinas (@Erika_MSantana@AngyMendozaH@JoGoyes) ! 🎵🐸🎶
https://t.co/oqjGai5iYw
🪶 Así es una clase de Colecciones en nuestro Museo.
🐦⬛ Jessica Burbano, asistente curadora de la colección de aves, nos cuenta sobre esta colección y qué aprenden nuestros estudiantes durante la sesión.
🧵 1/ New study on squamate color evolution hits the press: we show that brightness variation in lizards & snakes is strongly linked to habitat openness 🌞 https://t.co/Jxd46s0rkb
En los últimos meses estuvimos trabajando en un dataset multi-taxonómico para bioacústica en el Magdalena Medio. Ahora será usado para la identificación automática en la competencia de BirdCLEF. Esperamos especialmente equipos de Latinoamérica, todxs invitadxs 🐸🦗🐒🐦🔊🤖
Male Amazon river dolphins have been documented rolling upside down and firing urine into the air - and other dolphins seem to follow the stream.
Read more: https://t.co/pveTH8wArZ
🚨 ¿Quarto o R Markdown? ¡Pregunta del millón! 🚨
A menudo mis alumnos me preguntan qué herramienta es mejor para sus proyectos de datos. Es difícil elegir, ambas son geniales, pero aquí te dejo mi opinión sobre lo que considero mejor de cada una:👇
#rstats#programming#code
Aunque es cierto que la coquí genera problemas en las ciudades donde habita, quedan muchos interrogantes acerca del uso de este tipo de productos. Su efecto sobre especies nativas, la identificación de especies por parte de los usuarios, el efecto sobre otros animales y el suelo.
📢 Acompáñanos al (re)Encuentro Colombiano de Biología Evolutiva este 12 de febrero en Medellín
Este evento gratuito es organizado en colaboración con el @ParqueExplora en conmemoración del Día de Darwin
Formulario de inscripción (presencial): https://t.co/kcPTmdOFxD (1/2)