On a number of recent wireframing projects we have encountered queries from clients about the use of drop-down menus.
A drop-down menu is a list of menu items that appear when the user clicks or hovers over the main navigation menu.
Our discussions typically centred on the pros and cons of drop-down menus, and options regarding their implementation, which we will summarise below.

Implementation 1: Sane.com.au
The above example from Sane.com.au, this is the simplest execution of a drop-down menu. It is a list of menu options representing the 2nd level navigation.
The following examples of drop-down menus are often called mega-menus, due to some of their characteristics as follows:
- A large amount of real-estate taken up on the page
- Can present more than one level of navigation
- Can support additional information
- Creative design such as imagery and icons
- Advertising

Implementation 2: HarveyNorman.com.au
In the above example taken from HarveyNorman.com.au, the drop-down provides a preview of 2nd and 3rd level navigation for the selected menu option. The links available in the TV & Audio drop-down menu are exactly the same as those presented on the left hand side of the TV and Audio section of the website.
The purpose of this implementation is to provide users with a quick ‘preview’ of the options available from any page of the website and effectively replicates the navigation options available within each section of the site.

Implementation 3. Carsales.com.au
In the above example taken from Carsales.com.au, rather than providing a preview of the 2nd and 3rd level navigation of the website, this implementation includes links to pages with customised search engines based on the users selection from the drop-down, e.g. body type, make or around lifestyle choices.

Implementation 4: Anz.com.au
In the above example taken from ANZ.com.au, the options presented in the drop-down menu are the only means of accessing 2nd level navigation options. If the user wishes to move between sub-sections (e.g. in the example above from “Products & services” to “Tools, forms & guides”) they need to do so via the drop-down menu. In this example, the menu is not just an additional or assistive means of accessing site content, it provides the only access to certain pages of the website.
Which of the above implementations you choose will depend upon the objectives of your site. Irrespective of the method you choose, there are a number of pros and cons to keep in mind when considering the use of drop-down menus.
Pros:
- Quick and direct access to content that can be 3 levels deep within a site
- A quick preview of content available within a section
- Disambiguation of potentially confusing menu labels, interacting with the drop-down can provide additional information about what is in that section, clarifying the meaning of a menu option
- The ability to prioritise visibility of content, which can be motivated by business rules.
- The ability to sell advertising space
Cons:
- The motor-control required to operate drop-down menus. On any drop-down menu, if the user rolls the cursor off the menu, it will de-activate. This requires a certain level of motor-control and dexterity.
- When using a mouse, the user may glide the cursor over many main navigation menus before deciding to click. This is why latency is built in, as it allows the user to choose whether or not they want to reveal the drop-down menu. By resting the cursor over the main navigation menu for a few seconds, the drop down menu will appear. Again this functionality, even with the convenience of latency, also relies on a certain level of motor-control and dexterity, which is more demanding than a simple click of a button.
Sane.com.au, HarveyNorman.com.au, Carsales.com.au, and ANZ.com.au are examples of sites that use drop-down menus differently, due to the nature and purpose of their content. When designing a website it’s worth considering how drop-down menus will be of benefit to your website.