"Tool" or "target" on vacuum cleaner pedal?

Question

I always get confused by the icons on my vacuum cleaner pedal.

Take a look at the upper icon.

Is that icon representing
1) The tool. I.e. "Your now using the pedal without the brush" (ergo, on a rug)
or
2) The target. I.e. "You can now use the pedal on a flat floor" (ergo, with the brush)

Actually, the icons aren't the main problem here. The lower icon clarifies a bit, so I can imagine what they are representing, but I think I ask myself "Is the brush in or out" just before I take a glance at the pedal. So my mental model wants the switch to indicate the status of the tool I'm using. Yet the tool is actually showing me the target where the tool should be used.

Do I (and my mental model) belong to the minority here? Is this a deliberate design decision based on user research? How could this have been solved to remove all ambiguity?

Answer 1

Since there is whitespace between the tool (the vacuum cleaner head) and the floor, your icons represents the target (floor surface) and not the tool. Otherwise the image representation would be without the white space in the icon, such as this:

One other notable difference is that the icons on the above image is oriented toward the operater of the vacuum cleaner, and not toward the pet looking at the vacuum cleaner.

Answer 2

The problem with most of these icons is that they only show either tool state or surface type. That introduces ambiguity, especially if the user doesn't know how vacuums operate in general or how this specific vacuum works.

The obvious solution is to illustrate usage, and that means we have to, at least, display both the tool state and the surface type.

For a simple vacuum type that uses brush on floors but not on carpets, it could be illustrated like this:

Answer 3

How could this have been solved to remove all ambiguity?

It can't. A user would need to have some experience with vacuum cleaners or have read the instructions.

An icon that indicates the state of the vacuum wouldn't be an improvement because it would still require knowledge of how that state applies to the use of the device. Is the brush-down-state for bare floors or carpets? My experience tells me brush-down-state is for carpets, but apparently that's not universally accepted:

if the icon says "brush down" or "brush up", we need the user to know that "brush down" is used on a flat floor.

(quote from Peter's comment on this page). I think only text can solve this problem, either on the device ("Hard floors", "Carpets") or in the instruction manual. We all know the problems with text but sometimes it's hard to beat.

Answer 4

There's really no "correct" answer here.

Any kind of information stored in the physical world is subject to interpretation. People have different understandings for the meanings of symbols, words, sounds, buildings, poems, etc... There's no way for anything to really be 100% clear, since our understanding of the world is built on our individual past experiences. Each person will see things a little differently.

However, our job as designers is to pick the form that best indicates the function of the machine. In this case, it looks like there are really two ways of doing things, and both work. The most "correct" design could be thought of as the one that maximizes understanding for the intended user. So, now it really depends on who we're building this for.

If we're building this for professionals who use this machine all day everyday, they're probably going to know when to use a brush and when not to. They may have training and need to use multiple different kinds of vacuums in a day. So, for them, it would probably be annoying to have to mentally reverse the symbols every time they use the machine. (If there's enough confusion, they may even go so far as to put tape or something over it to correct the labels.)

But, if we're building this for college freshmen, who have never vacuumed in their lives, chances are they'll have no idea when to use a brush. (They may not even know that it has a brush!) In this case, the labels may work perfectly. It's all a matter of what mental model the user starts with.

Answer 5

The primary issue hear is that there are too many factors for a single pair of icons to consistently represent across makes and cultures. Not all vacuum cleaner attachments work the same way, nor does everybody bring a consistent set of assumptions about what the icons are likely to represent.

The primary variables are:

• Floor surface.

• Brush type.

• Brush state.

• Operation height.

• Other design factors such as retractable sweeps or channeling.

For many attachments, the primary adjustment is the operation height or gap between the floor and the unit. This is often adjusted with retractable wheels or guides. Vacuuming carpets often benefits from a snugger fit where the unit rides low whereas smooth floors often benefit from some air space between the attachment and the floor allowing crumbs to pass under and air to flow. This option is often combined with other features such as a sweep or static brush, and also often has more than a binary mode: there are often 3 height steps.

Another frequent option is the state of a rotary brush. Of rotary brushes, two major kinds exist:

• Beater bars designed for cleaning carpets
• Sweeps designed for solid floors.

The latter is less common, but often employed in suction powered heads that use the air flow to power the brush. These brushes tend to be gentle and only useful for dislodging small particulate matter from hard surfaces. The former kind is more common and is usually powered by a dedicated motor. The brush unit often has a mixture of soft brushes and hard bars designed to stir up carpet threads then give them a good whack to dislodge solid matter. This kind is entirely unsuitable for hard floor surfaces, hence the option to retract them on multi-purpose heads.

Any given vacuum attachment may only have adjustments for one of the above items and may only be a binary state switch, but the icon design must account for and disambiguate several possible factors.

My suggestion for the most clear depiction of possible states would be to include both the state of the tool and the floor in the icon. At the same time I would suggest that a cross section view of the tool rather than the front elevation view shown in most of the examples here would be more effective. Which side was the tool vs. floor would be more clear, and the state of brushes being retracted or extended and whether that was meant for hard or fuzzy surfaces could be more clearly demonstrated.

Answer 6

I'd say the icon currently represents one of 2 states: with and without the brush. The UX problem is that the user needs to know what that means - rug or hard floor (otherwise there is an additional mental step to take, and we want to reduce cognitive load). One way to resolve it would be to write in the local language what each state means; I'm not aware of any commonly-used icons or symbols that could be used here. The designers could perhaps have used an icon to represent a wooden floor, then 'not a wooden floor' (same icon with a cross through it)? I think words would be clearer, but then you have the internationalisation problem. Either way it's a tricky one!

Answer 7

I think your mental model i.e. option 1) is correct - i.e. the brush head should be simple and just tell you whether brush is in or out rather than try to give you a helpful tip on what surface to use (which completely inverts the logic).

The Nilfisk hoover we have does away with any icons but you have to push on the longer half of the lever against a spring to push the brushes out and pushing on the other side of the lever snaps the brushes back in. Thus there is a mental concept of 'pushing' the brushes out of the head or letting them spring back in - similar to this:

Dyson also has more clear icons that clearly show the brushes connected to the hoover head. (The footprint just means 'put ya foot here', although I haven't figured out still what the inset footprint vs the outset footprint indicates)

Answer 8

There are two possible representations here:

1. The symbols Represent the tool state.
2. The symbols represent the target state.

I am pretty sure that the target state is represented here. (I.E. The rug is represented) And that you are clearly a minority in this case.

That's because most people are not interested in symbolic instructions on their tools (aside from the guidance they offer). Also, few that actually know or care that the brush raises or lowers based on the setting. Think about it, it's facing the ground. No one would know unless they looked or were curious. Even the noise change doesn't mean people will know what the noise is from.

In my opinion the symbol should represent the purpose, result or goal of the setting, not the state of the tool (unless the state of the tool is representative of the goal... an example being a padlock). To bring the point home, remove the symbology. Imagine written instructions next to the button saying: "Lower the brush"/ "Raise the brush" No one would know what the purpose was for. But if it said "Carpets"/"Bare Floors" is would be obvious.

Answer 9

State of the tool: for experienced vacuumers (meaning you are familiar with your surfaces and how they interact with the head type)

State of the surface: for novice vacuumers (meaning you are unfamiliar with your surfaces and how they interact with the head type, and haven’t vacuumed before).

The complicating factor here is that recommended usage and optimum usage are often different in these sort of appliances so labelling by surface to ensure recommended usage is problematic. Additionally, novice vacuumers will be a tiny segment as vacuuming is a very easy skill to gain experience in.

My conclusion: State of the tool is more important, because of surface x head type interactions (e.g. sometimes carpets are cleaned best without the brush, sometimes with the brush, and ditto for non-carpet surfaces).

Answer 10

I think the issue is that you shouldn't have to know if the brush is on or off. What the vacuum wants to 'know' is what you are vacuuming...bare floors, or a carpeted floor.

As such, the icons should indicate the floor type, as that's the most obvious for the user to figure out. So my answer is that the icons should indicate the target and nothing else--at least for vacuum cleaners.

The dyson we have does just this (shows a line for bare floors, a line with tassels for carpet) as well as puts a label on each to make it even that much more clearer.

Answer 11

This situation demonstrates where icons are worse than using text:

The easiest labelling is

Top: Wood

Bottom: Carpet

No complex mental processing of icons required !

If Icons are required to reduce manufacturing costs then

Carpet = Picture of Sheep

Wood = Picture of Tree