Observing Mobile Interactions

Travelling around in public buses gives you a lot of exposure to varied people and their behaviors. As usual I missed my regular "A/C" volvo so i took the general bus. A sudden change in environment surely teaches you a lot with what the rest of the world is doing. As i enter this overflowing bus after much reluctance, I am exposed to a totally differnt environment.In front of me is a carpentar, with his hammer and saw packed in a small little bag, almost ready to cut anything that comes its way.
He sort of pushes me inside, making sure i dont occupy his existing space.

As I move on inside, I get a corner to stand. But for a curious mind like mind standing without any action seemed boring. So as i keep adjusting my heavy IBM bag against all the people who pass behind me, my eyes get locked by a brand new Samsung Wave. Not that i had not seen one before, but what was interesting was how the owner of this brand new piece of technology was using it. He started the web browser on his phone, for a few seconds he seemed to struggle quiet a bit. The shiny surface of the phone clearly showed that it was a recent buy, and his struggle surely showed that it was his first time to use it. However this wasnt the astonishing part, its quiet common to get to see first time users. But the interesting part was yet to come... as he struggled through the phone browser..and as i became more shameless to continue peeping into his phone, I could start seeing an interesting interaction struggle he had for a long time.
On successfully managing to go to google.com, he tried to enter a keyword...firstly for some time he struggled to type what he really wanted to. He then selected one of the auto keywords that google displayed.
Now comes the interesting part. On display of the result he couldnt scroll. His natural scroll pattern seemed to be going in moving the thumb from bottom to top. But it seemed that the scroll functionality was completely opposite and this couldnt be figured out by him. As a so called "Designer" I was tempted to tell him the correct way, but the researcher inside me didnt allow me. I wanted to know what he does next. As expected after three attempts he gave up, i.e. closed the app. It was interesting to see, how a basic interaction like scrolling, without proper visual affordance can demotivate a user to use an application. I am not generalizing here, but what i just saw was the role of IxD in the success of any application.

After a while i finally got a seat.By now my senses had become sharp to anything around me. And guess what on my left i see a visual challenged individual operating a mobile phone. This wasnt the first time i was seeing this, but the insight i got this time was unique. As i keenly observed him use his phone, i saw him taking the phone screen close to his eye as he operated the phone. At first i thought its for listening to sound. But it was actually the change in the light between the screens that he was somehow able to sense. What striked me is how important interscreen light change can be. After hearing change in sound he selected the options one by one to succesfully make a call.

Comparing both the situations, I could see the importance of interaction for the later being more critical. For the samsung person, what he struggled with was simple yet not crucial. However in case of the second situation the interaction played a crucial role.
Thoughts wandered across the possibilities for both the cases, and perhaps the value addition that IxD can make in any existing product. IxD may be invisible but it surely is not optional.