Welcome back to the AI Bayeslab Statistics series. Today, let’s grasp some basic concepts of the effect size so that we can better understand the signal detection theory in the next post.
Definition of Today:
Effect size:
It acts as a benchmark for meta-analysis, usually representing the relative extent of difference. This measure can be derived by comparing different studies.
Omega Squared (ω2):
An index that quantifies the influence of independent variables on the dependent variable, showing how much of the dependent variable’s variation is accounted for by changes in the independent variable.
In this post, you’ll demystify the complex statistical concepts mentioned earlier and discover how to implement them in your business decisions and management using straightforward language. I am excited to provide the public with free consumer statistics, which I hope will positively impact your daily life.
What is the meta-analysis?
For instance, a significant discussion exists regarding the advantages of sunlight for the immune system. Thus, there is an entire field of research focused on the effects of long-wave light on the human body. Some of this research shows a significant difference, while others do not. Therefore, we need a technical method to synthesize all the related research and conduct further investigation. This is the meta-analysis.
What is the effect size?
Regarding the effect size, it serves as a benchmark for meta-analysis, typically indicating the relative extent of difference. This measure can be obtained by comparing the results of various studies.
Effect size formula of a single population t-test

Effect size formula of two populations t-test

What is omega squared(ω2)?
Omega squared (ω²) quantifies effect size and indicates the strength of association within a population.
It assesses how much of the variation in the response variables (dependent variables) can be attributed to the explanatory variables. Often regarded as a more reliable measure than eta-squared, omega-squared is particularly valuable when working with small sample sizes.
Omega squared ω2 formula

When the difference between means is not significant, and the absolute value of t is less than 1, omega squared is just a replication. The more omega, the greater the influence between variables.
AI example: Omega squared calculation
We now use AI Bayeslab Prompts to display omega-squared values calculated from various t-values. The difference in response to light due to inflammation is 56% and 8.85% due to duration.

Thank you for reading this installment today. We discussed what effect size is and explained the Omega squared. In the next post, let’s explore signal detection theory (SDT) in more detail.
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