Answer:
What are the most effective dog-training techniques? - a blog from an expert dog trainer
Why are dogs especially intelligent animals? - the encyclopedia entry "Canine"
How do scientists measure the intelligence of dogs? - an article from the Journal of Animal Biology
Step-by-step explanation:
1. Dog-training : dog trainer!
2. Encyclopedias often give reasons on why and what more than anything.
3. Science journals give their methods and reasoning on their projects a lot.