Weak thesis statements are too broad or general. Examples of weak thesis statements are below:
Weak Thesis A : The fall of the Ottoman Empire was bad.
How to improve: The fall of the Ottoman Empire had a negative effect on the other countries in the region.
Weak Thesis B : The internet has been very useful for the economy.
How to improve: The internet has been useful for the improvement of the US economy because of its ability to expand the commerce and spur entrepreneurship.