11.5.4 Analogy Analogy draws on similar situations to provide ideas for invention and design. Alexander Graham Bell used the analogy of the human ear when designing telephone apparatus to receive sound. As mentioned above, his first receivers were much better than his transmitters where the analogy with the ear didn't work as well. When devising their flying machine, the Wright brothers used the analogy of soaring birds twisting their wings to restore balance. They designed the wings of their aircraft to be
12.1.1 Survey questionnaires Questionnaires are lists of questions that enable information to be gathered efficiently from a relatively large number of respondents. Most questionnaires require a fixed type of response, such as a choice between available answers, or along a scale of response. For example, a product design questionnaire might suggest, ‘I found the product easy to use’ and provide a five-point scale of response from ‘agree strongly’ to ‘disagree strongly’. Or a question might be, ‘how often do
8.1 Making usable products This section reveals that many modern products need to usable by our minds as much as our bodies. Products need to be understandable, and present information and feedback in meaningful ways. A lot of ergonomics research is aimed at establishing guidelines, standards or rules that can be applied by designers in a variety of situations. Where this applies to the physical use of products, much of it is based on standard body measurements. These body measurements are known as anthropomet
2.6 Precipitation
Precipitation
is defined as the depth of rainfall, or the water equivalent of snow, sleet and hail falling during a given measurement period. It may be in the form of rain, snow, sleet or hail, or in minor forms such as dew and hoar frost, but existing theories do not yet satisfactorily account for all the observed characteristics. In tropical climates, precipitation occurs as a result of the gradual coalescence of the tiny condensed droplets as they collide within the cloud
2.3 Transpiration If there were no vegetation, the rate of evaporation from land surfaces after rain would diminish rapidly to a very low value. Plants increase this rate by transpiration. In this process, water is transferred from the soil through the roots to the leaves by osmosis and capillary action. Water evaporates from the surface of the leaves and the resulting vapour diffuses into the atmosphere. For hydrological measurements, this phenomenon is frequently lumped with evaporation because the two proce
1 Some facts about water