How to Use "rigorous" with Example Sentences

1. You could always make the tests more rigorous .
2. It is a complete , rigorous piece of research .
3. An obvious problem is that self-quantification experiments lack the rigorous controls and double-blinding of pharmaceutical trials .
4. Second , I don 't think there is a sufficiently rigorous approach to causality .
5. Wow , I believe their participation will make this year 's competition even more interesting and rigorous .