With or without a cable, special keys or an ergonomic shape — when buying a mouse and keyboard there are a lot of decisions to be made. The experts say that the most important factor is what will the devices be used for — game players will have different needs to office workers.

How the user experiences the computer depends a lot on the input devices, according to a study by the Swiss Federal Institute of Technology (ETH) in Zurich. For example the wrong keyboard can lead to wrist problems.

Users should think carefully before buying input devices. In the office particularly a person’s hands are on the keyboard and mouse all day so it’s vital that they’re comfortable.

“The size of the mouse should not be based solely on the size of the hand,” said Christoph Giese of the German computer magazine Chip.

“It’s also important how the user holds the mouse.” For example some users put their whole hand over the mouse so the mouse must match the size of the palm while other people who use just three fingers on the device can live with a smaller model.

With modern mice which use optical scanning a mouse pad is no longer required. In this case the important thing is that the mouse is on the right surface. Glass, precious metals, mirrors or black velvet should be avoided, according to Giese.

When choosing a keyboard the situation is similar to picking a mouse: whether it has forward or backward-inclined keys, a wrist rest or a split keyboard layout, what matters most are individual needs.

Many keyboards now come with keys that can be programmed to carry out special functions such as volume control.

When game-playing is the goal, personal taste is again the dominant factor. “While one player likes to use the keyboard for game functions, another prefers to use the mouse buttons, for example in first-person-shooter games to shoot or jump,” said Frank Stoewer of German computer magazine PC Games Hardware.

The number of special keys also depends on the game, for example command combinations that can be achieved with a single keystroke.

But a good player keyboard requires more than just gimmicks and macro-keys, according to Stoewer. “The feel, the ergonomic aspects such as height adjustment, the wrist rest, a clear layout, the shape, as well as the tactile feel of the keys, in my opinion these are more important.” Cable-free keyboards and mice have long been available and latency is no longer an issue for these wireless devices, said Stoewer.

However, there are other drawbacks such as the need for batteries.

Devices that communicate wirelessly are clearly preferable to ones that communicate via infrared with a receiver, Giese said.

The touchscreen keyboards of tablet computers can be difficult to operate. In this case an external keyboard can be attached. “Buyers should always look first at the accessories shop of the manufacturer for the right parts for their device,” said Giese.

Thanks to Bluetooth, mice and keyboards are compatible with most tablets. Connections have a range of at least 10 metres and are less susceptible to interference than radio technology, although more power is used.