A9.1. Meaning of symbols

The presence of symbols, images or pictographic signs must not lead to any difficulty of interpretation, which can cause frustration or lack of interest, and should not lead to any misinterpretation or confusion, particularly in the case of an emergency or lack of attention. Pictograms (which designate an object with a distinctive and stylized model based on its image) are, in principle, not limited by the requirements of language. This allows, firstly, for them to be used wisely and without giving them a meaning that cannot be communicated by their nature, and secondly, for mindfulness of cultural elements which may lead to erroneous interpretations.

Regardless of the means used, it remains preferable in all cases to express the directions (instructions, warnings, degrees or state) in terms of and related to usage, rather than technical or instrumental aspects (heat rather than electric resistance; an air flow rather than a ventilator, for example).

The indications (usually made graphically) do not have to be present and visible in the best possible lighting conditions in order for them to be easy to locate, identify or read in real usage conditions (position in the space, lighting, shadowy areas, etc.). Furthermore, the lack of durability or the risk of temporary impairment (by dirt, for example) of initially visible indications should not affect their readability over a relatively long period of time.

The identification of the individual mechanisms to utilize or take into account in at the right time is fundamental in order to act quickly, with greater certainty and more often, without the need of conscious visual controls (just “at a glance”). The means of differentiating them, for the benefit of the user, appear as follows, in decreasing order of preference:

1. 1) The spatial location of the mechanisms relative to the whole of the device or of the control area (to avoid associated or superimposed mechanisms, or even different functions depending on the configuration and the current operational mode).
2. 2) The shape of the mechanisms, regarding their form, their volume and the possible presence of shapes or surfaces which can be perceived by touch (in cases such as fumbling or confirmation on the first try).
3. 3) The graphics associated with the mechanisms to identify, subject to the requirements above.
4. 4) The color alone rarely allows effective (certain and fast) identification. However, it can participate in addition to other aids (redundancy in the ease and certainty of identifying mechanisms already differentiated by other means).

The fact that mechanisms are clearly differentiated is evidently not enough to identify them in terms of their functional role. However, this differentiation does help to prevent confusion in perception between competing, similar or neighboring mechanisms, at the same exact moment of acting on or using one of them. Only the mechanisms involved in the operation to be undertaken must be made worthy of interest and be established by their relevance in contrast to the rest of the system, which must be temporarily relegated to the level of “background”.

The language of the literal or abbreviated indications must privilege exclusively that used by the users.

Combining different languages in instructions should be avoided. Literal translations, or the use of a word that is the same in the two languages but not strictly synonymous is also to be avoided (such as the term “validation” in French and English).

In all cases, it is preferable for the user to communicate with the system in clear language, with plain, everyday words and phrases, rather than with abbreviations that harbor often unavoidable ambiguities, or even with expressions from technical (digital, electronic, instrumental, functional) jargon.

From a conceptual point of view, the indications must specifically adopt the point of view of the operators, with their concerns and their motivations, rather than the system itself and its internal operation.

As far as possible, signs that are conventional and abstract, or those that are linguistic and have the value of a particular code (even those that are commonly used on other devices (with meanings that are often different)), are to be avoided.

No matter how they are presented, the use of keys involves an additional step which it is better to skip altogether. The use of pictographic symbols that are sufficient by themselves can be considered, but they must be sufficiently intelligible not to lead to confusion or misinterpretation, especially due to the cultural differences. It should be recalled that a symbol refers to an object, and may not designate an action (unless it is in a coded language). Therefore, they must only be used to communicate exactly what they signify (the shape of a “key” indicates a key to be used, or something not to be forgotten, but not a lock when it has been locked by a key).

The following should be avoided as well:

• – inaccuracies and ambiguities often beginning from a designation of state (e.g. battery failure can mean both “missing battery” or “battery defect” (defect or lack of charge));
• – unsuitable or inaccurate expressions (e.g. “test correct” (this means that the condition of the batteries tested is correct, not the test itself)).

A9.2. Evidence of the functions and meaning of lighted indicators

It is obviously not enough that the system is disposed of a couple lights, so that the color and context of the signal’s apparition allows the user (who is often unaccustomed to understanding their meaning) to guess and memories them. Providing a key, for example, can reduce the risk of doubt and confusion over meaning (or users wrongly believing that they can remember). If an indicator is not related to a button or a command mechanism, it is preferable for it not to be located nearby, in order to prevent the risk of confusion. On the contrary, if a signal is given (such as flashing) during a particular function, it is strongly recommended that the indicator should have the closest relationship possible with the key or mechanism that is to be operated, or that is needed to stop or initiate the operation. Unless the various states of an indicator are explicitly identified on the system (off, on or flashing, for example), it is very difficult to understand beforehand and then remember afterwards that a single indicator may refer to a type of circumstance only when it is switched off or switched on (battery charging or potential bad contact, for example) and that it refers to quite different circumstances when it flashes or stops flashing (change or deletion of access code, for example).

An effort should be made to avoid “guessing games” when it comes to using security systems!

If an indicator shows the startup and continued supply of voltage used by a system while the latter depends on an action independent of the control mechanisms, said indicator should not enter into the strict framework of the area of those command mechanisms.

In any case, for Western users, an identification or control of an initial state must always begin at the top left of the system. A green-colored indicator is preferable to a yellow or orange one to indicate that the system has been determined to be in working order (if nothing else opposes it and indicates as such).

The identification of an indicator with a pictogram of an electric battery may be considered. If instead it is an indicator of a battery being charged or a battery pack, it will rather be associated with the button used to perform the check. The indicator could be green when the conditions are satisfactory, and could turn orange and flash when the charge becomes insufficient and action is required. The turned-off state obviously corresponds to a lack of power (dead battery, missing batteries, contact failure or another cause).