That is probably a question a lot of people ask when installing a new WiFi router at home. The answer was provided by Jason Cole in this rather highly mathematical (more like physics actually) demonstration in his own apartment.
By positioning the WiFi router at an optimal location, we could get a better reception. Jason Cole shows us how does that look like in this model.2
This area mapping provides a more visual display of how signal strength is affected by obstructions or interference and signal refraction.
If only we could also have a simple tool such as this to help us decide where to put that WiFi router at home, that would have been better.