… and more especially … how can you use this information in your project ?
The 5th percentile mark is the point below which 5% of the population is represented in the graph, the 95th percentile is similarly the point above which the tallest 5% of the population are represented. Predictably the 50th percentile mark is the point at which 50% are below that height and 50% are above. The line down the middle in this case is the most common height found in the sample – this the ‘modal height’. Since this curve is symmetrical – the ‘average’ height is also shown at the line in the middle – so the‘mean’ height point coincides with the ‘median‘. Of course it doesn’t always follow that the curve will be a ‘normal’ bell-shaped one – it may be ‘skewed’ to one end – if for example the distribution curve of people within a primary school were surveyed. As there would be many small children within the sample, the curve would be towards the ‘shorter‘ end. So aiming a product at a particular group of people needs to use anthropometric data such as this – before it is designed.
“Good product-design is the ability to make products that the customer wants and can use comfortably.‘ Consequently a good product might be expected to sell well since it seems to have been designed for the user who possess it. Using thisANTHROPOMETRIC data allows the designer to create well-designed items. These well designed items will work well and be comfortable to use – and so will be ERGONOMICALLY well designed. Let’s say you have been given the Design Brief of a small table to design – Apart from checking out the size of people who might use it – it would also be necessary to check out the ‘footprint’ of the items that might most usually be placed on it. If the table were to be a bedside tale – you might find an alarm clock; a radio perhaps; a photo maybe and space for a drink ….. So how big should the table be … ? Apart from the features that are listed here - that will become part of the SPECIFICATION for the product - What other detailed factors would influence the range and general approach you would have as a designer to producing your designs ? If you are unsure then check out the section on the DESIGN CYCLE - as this covers the different considerations in the DESIGN PROCESS. Consider as many points as you think relevant when completing the PDS - the PRODUCT DESIGN SPECIFICATION
Have you ever wondered how it is that you can go into a shop and buy a shirt or a pair of shoes that fit you pretty well – when almost nobody you know is the same shape and size as you ? Well designers want to make the most of their products – they need them to be successful to survive - and so they are made with the most ‘usual’ sizes of people in mind.