Related Experiment Video
Updated: May 2, 2026

Problem-Solving Before Instruction PS-I: A Protocol for Assessment and Intervention in Students with Different Abilities
Published on: September 11, 2021
Validity of the MAGIC study: sufficient for recommendations?
Abstract:
According to the recommendations of the German S3 guideline, perioperative chemotherapy is an integral part of the treatment concept for advanced gastric cancer. The leading trial which examined the effects of perioperative chemotherapy is the MAGIC study. An examination of the validity of this study with a standardized method revealed shortcomings in the six areas: design, protocol, selection of patients, randomization / homogeneity of patient groups, quality of the surgical care and the statistical evaluation. These shortcomings and their influence on the study results are described in this paper to reveal the importance of these effects for discussion in guidelines committees.
Related Concept Videos
Reliability and Validity
Magical Thinking
Statistical Significance
Regression Toward the Mean
Testing a Claim about Standard Deviation
The hypothesis testing for the claim of population standard deviation (or variance) requires the data and samples to be random and unbiased. The population distribution also must be normal. There is no specific requirement on the sample size as the estimation is based on the chi-square distribution.
As a first step, the hypothesis (null and alternative) concerning the claim about...
What is an Experiment?

