Shelling in eastern Ukraine spread to a new front as towering columns of smoke rose outside a city in Ukraine's far sout

The video discusses studies that were found to be invalid, highlighting issues in research validity.

What factors can lead to a study being considered invalid?

How can researchers ensure the validity of their studies?

What are the consequences of conducting an invalid study?

Can you provide examples of common mistakes that lead to invalid studies?

In your opinion, what is the most important aspect of study design to maintain validity?