They joined the train at Cambridge, the halfway point on the line from Kings Lynn in Norfolk to Kings Cross in London. Two ladies, about 60 years old, dropping wearily into their seats with the air of relief worn by those who feel they ‘just made’ their train.

Still catching their breath, they began a detailed analysis of what had transpired at the station.

“I’d got there half an hour before. I always worry,” said one.

“Oh, me too, I don’t know how we missed each other!”

It seems one had waited on the platform, looking for the other, who had taken a seat in the waiting room of the station cafe. Each had thought the other was simply running late and had held out, with growing anxiety, hoping the other would arrive, before finally rushing for the train at the last minute. It was only in their hurried dash for the train they’d finally seen each other, running for the same carriage from different parts of the station.

“I tried to call,” explained the first lady. “But then I must not have your number, I couldn’t see it on that email, so I sent a message instead.”

“Oh no, I wouldn’t have got that. I don’t have one of those phones,” her companion replied. She produced her phone as evidence: an ancient Samsung flip design, its silver, metallic effect paint worn down to the cheap plastic in many places. It looked as if it may struggle to receive an analogue signal, let alone email.

They were on their way to an art gallery in London, seemingly part of a larger group of retirees who attended regular outings like this, using email messages to manage the arrangements.

“You must get a smartphone,” insisted the more progressive of the pair. “I love mine. I mean I don’t have one of the really top ones – I don’t need to spend all that each month – but it is still quite a good one, I think.”

The implication was clear. Monthly cost, presumably paid to the network from which she’d bought her phone, determined the capabilities of her phone. I couldn’t say for sure which model it was, but it might have been a smallish Nokia Lumia. If I had to guess, I’d say a 520.

“Must I? I don’t see why. I mean what can you do with that I can’t do with this?” the other asked, quite seriously, without a hint of irony as she examined the clamshell feature phone in her hands.

“Well, if nothing else for the texting. With this one I just tap and tap – and look it gives me the whole word, right there, and I can see it all. You won’t know yourself, it’s wonderful! I used to hate all that tapping away at those little keys.”

The killer feature of the smartphone for this particular user, it seemed, was the simplicity of text entry afforded by the onscreen QWERTY keyboard.

“I don’t know,” sighed the other. “I just don’t understand all this. I mean people ask me for my phone number all the time. It is like it’s a right these days, isn’t it? I mean, surely it is my right not to have one of these things! I don’t want to be reachable all the time!” Her issues with technology, it seemed, went somewhat deeper than simply lagging behind the curve.

“I mean, I did think about it. I do think about it. But they were too small. I could never get on with that. I liked the iPads, but they were too big. I’ve been looking and the phones seem to be getting bigger. I’m waiting until they’re just right. Bigger than that,” she said, pointing at her friend’s smartphone, “But smaller than the iPad.”

“Well, you could wait around forever,” cautioned the other. “But I’m doing so much with it already.”

“I’m waiting until I can really do something with it,” continued her friend, unconvinced. “When they get to the right size, I’m going to get one and I’ll put everything on it. I could have my whole life on there. Photos, letters… It will have to store all those things I’ve got on the computer. It’ll be my everything device.”

I was reminded of how most analysts scoffed at the Samsung Galaxy Note when it emerged. Experts cited the ergonomic limits of hand size and competing manufacturers nodded wisely and stated with confidence how screen sizes above 5 inches would remain a small niche.

Yet here, in this unguarded conversation between two users, we find the underlying motivations which established an intrinsic link between smarter phones and bigger screens. Imagine how different the research outcome might have been in a lab environment or swayed by the bias of survey questions? How would the feature phone user have answered if she’d been shown a prototype of a smartphone and asked about its size? How could the designers have asked their questions to reveal the deeper reasons behind her choices? Would they have found the link with the media on her PC, the notion she didn’t want it to be a phone at all, but rather a more pocketable iPad, for private consumption and creation rather than communication?

Just as the train began to arrive in London, the feature phone user turned to her companion, her voice dropping to a whisper.

“What’s that?” she said, pointing surreptitiously to the Blackberry Passport I’d been working on for most of the journey.

“I’ve never seen one like that,” her friend replied, intrigued.

“No, neither have I. But look at it. I could do a lot with something like that,” she whispered, her voice trailing off as the two of them packed up their bags and began bundling their way towards the doors as the train drew into London.

Who would have thought to include a 60 year old retiree with a Samsung flip phone in the focus group for the Blackberry Passport?