Sometimes a seemingly insignificant design feature can carry bigger assumptions and implications for the lifestyle of the user.
Consider two reusable water bottles, as pictured above. Both have a capacity of 20 ounces. Both have a small opening designed for drinking out of and a larger opening designed for adding ice or other solids. Both have about the same footprint and will fit most cars’ cup-holders. The only real difference is the shape of the upper portion.
To fill either one up to maximum capacity, you have to first secure the top part and then make sure your stream of liquid is narrow enough to fit easily through the small “drinking” opening. The alternative is to unscrew the top part and fill up the bottle through the wide opening, which is much easier, but won’t get the bottle all the way full.
The design of the bottle on the left assumes that its users have access to a steady narrow stream of water and can easily hold the bottle still long enough to fill it up through that small hole. The alternative approach—unscrewing the top part and filling it through the large opening—would end up causing users to forfeit about a quarter of the bottle’s capacity, merely because of the long slender design of the bottle’s neck.
The design of the bottle on the right mitigates most of this problem by only placing about a tenth of the volume in the top part. This means it can be filled by the easier method of unscrewing the top part, without much sacrifice in capacity. In turn, this means assumptions about what kind of stream of water and bottle-holding abilities the user has access to are no longer necessary.
It’s usually a good thing when we can tweak a design so the need to assume things about our users or inadvertently force requirements on them is eliminated.
These two styles of bottles are both for sale right now in many different stores, and the people who bought each one are getting very different experiences even though they bought very similar reusable water bottles.
This example does not demonstrate the most dramatic impact on users a design can have, but it demonstrates how there can be more of an impact than the designers may have considered. The little things matter, and design works out better if you account for that.