The grandeur of Milan had a strong impact on me. Years ago I was visiting a friend for a few days who, while we were visiting Parco Sempione, realized that I was a bit strange. He asked me: “Mattia, is everything okay?”
The city is so big that I felt lost, disorientated. And living in a small town in the Friulian countryside like Castions di Zoppola, I suffered its effect. Milan is huge and there are many things to visit. In the first few days Michele acted as my guide, taking me to see Simplon Park, the Cathedral, the Arch of Peace and other destinations. I saw some of the main attractions, but I didn't see them all. This is a good approach to visiting a city, but it doesn't hold up on its own.
On the last day I visited it alone: I got some ideas of what to see in the morning, while in the afternoon I walked to enjoy it a bit without a specific objective. After taking the subway and exploring the city, I found myself in front of the "Corriere della Sera" headquarters.
Damn, what a nice surprise! "Il Corriere" was my daily source of information, I didn't know the office was there and it was nice to find it like that, without any expectations. I hadn't chosen to visit it and it was a nice moment, because I had discovered something new without wanting to.
I compare those days in Milan with the Application Testing approach, because both can be used while testing software.
The first allows you to check the most important things in less time, but focusing only on the "main monuments" of the application is not enough and is not sufficient to increase quality.
The second approach allows you to take into account secondary roads and other interesting alleys that deserve further investigation and should be taken into consideration. With this method I relive every time the same emotions and enthusiasm I felt after discovering the headquarters of the "Corriere della Sera".
Let's take an example. To register on websites there are forms in which to enter personal data.
Usually these contain the classic fields: name, surname, email, telephone and many others.
How do we approach testing the first two fields?
Following the examples of my trip to Milan, the first approach would lead to testing them with the more classic ones: Mattia, Andrea, Marco. Zanchin, Bocelli, Galli.
However, testing them just like this is not enough, these fields need to be explored a little more: there are names with spaces (Anna Maria), with accents (Niccolò), with hyphens (John-Paul) and long names (Mariagiovanna/Pierferdinando).
It's the same thing with surnames: there are those with spaces (De Nicolao), with apostrophes (D'Andrea/D'arco) and here too surnames with a certain length. If the application is international, the Asian (マッティア) and Arabic (ماتيا) names must also be checked. And to give further solidity to the final product, cases of error must also be taken into consideration.
Trovo importante durante il test di un’applicativo allargare gli orizzonti e non concentrarsi solamente sulle casistiche principali. Il concetto emerso da questi due semplici campi può essere esteso a qualsiasi funzionalità per essere compreso maggiormente, come un banale login: non è sufficiente testare l’accesso con email e password corrette ma vanno provate altre situazioni come email errata, password sbagliata e login avvenuto dopo il reset delle credenziali.
On that journey I benefited from the union of the two approaches, and I applied the same solution for every software I explored.
Fonte: “Exploratory Software Testing: tips, tricks, tours, and techniques to guide test design”, James Whittaker
English (UK) 
Italiano