Sliders are probably the hardest phones for people with mechanical issues to use. Pressing and sliding is an awkward action, but because most of the people who buy phones for shops and networks are quite young – by definition they are not retired – and all are phone savvy the idea that sliding a phone open is an intellectual one not an everyday problem.

Big Button Slider

The Emporia Lifephone has great big buttons but the slide mechanism means they have to be flat and this reduces travel

Siemens SL10 was an early slider

The need for a flat keyboard gave the SL10 a poor feel

There are some advantages to sliders. Like a clam they hide the “I’ve got poor eyesight” big buttons, and they can have those large buttons and still have a large display in a sensible sized phone. The best example of this is the Emporia LifePhone which has huge buttons and a great screen.

Sliders often have the dial and hang-up key on the outside which can lead to in-pocket dialling but they can share the key protection advantage of a clam. Perhaps the best reason for using a slider is that you can have the keys protected and still see the big screen. You don’t need an expensive second screen, and the main screen is big, so again it works well with caller ID and C-Caller.

Sliders are however the worst phones for big button travel and

separation. The keyboard needs to be flat for the top to slide smoothly and you can’t have spaces between the large buttons. Indeed one of the very first sliders, which was also one of the first colour phones, the Siemens SL10 had a horrid keypad.

The centre of gravity problems which afflict a clamshell phone are not so acute on a slider. It’s far less likely to tumble out of your hand, and you can make the slide operation the method for answering and hanging up a call. It just doesn’t seem as satisfying as a clam.

Rotators look call but are not that easy to use

The beautiful Motorola Aura still commands a high price second-hand but isn't that easy to use because of the flat keypad with limited travel and the rotator mechanism while fantastically innovative, is a little awkward.

Emporia's first clamshell is the Click

The Emporia Click is a clamshell big button phone which has been announced but is not yet available.

While Bar, Clam and Slider are the main form factors of a mobile phone there are a few others which have featured in the past. The flip phone, typified by the Motorola Microtac of the 1990s. These have the advantage over a clam of covering mouth to reduce background noise although often the microphone was in the same part of the phone as the keypad and not the flip. It’s a good form factor with many of the advantages of a clam but again very unfashionable.

A similar fate has befallen the jack-knife-like rotator, typified by the beautiful Motorola V70 and expensive Aura.

The Aura was made to the same standards as an expensive watch with cogs visible through a glass panel that meshed as the blade rotated.

Of all the form factors the rotator is the one which is probably the least suitable for older people as you need to hold it in a way that allows for the front to move without losing grip on the phone and then push the top. It’s a combination of fine motor effort which is awkward for those with even the most agile fingers.  This has not prevented the Aura from still commanding a significant premium on e-Bay.

While the lack of innovation in the designs of tablets and QWERTY phones is to be lamented some of the more exciting designs such as sliders and rotators are not right either.

The fantastic market success of the Doro 410 as a clamshell phone with large buttons shows that it’s the form factor with the most potential. Not least because the market for big button phones is fantastically price sensitive and the Doro is quite a pricey phone.

Emporia is one of the leading manufacturers of easy to use mobile phones and has announced the ‘click’ a clamshell big button phone. This will shart shipping in Germany and emporia’s native Austria shortly.