If you are developing a nice and usable search engine on your website, you have most probably thought of implementing a ‘search suggest’ feature that gives useful suggestions to the user in a drop down menu. But have you considered that the search suggestions can be all different depending on what you want to achieve with the feature? Let’s have a look at the anatomy of Search Suggest – read before you start the development or improvement of your own suggest-implementation. The usability results can differ a lot depending on what model you choose.
(A Danish version of this blog post is available)
The idea behind Search Suggest
Google popularized the suggest functionality in 2008, when they introduced it as an experiment. The goal was to help the user formulate queries, reduce spelling errors and reduce keystrokes.
Google’s suggest feature was later named Autocomplete. Other names for similar features on other web sites are “type-ahead” and “search assist”.
But Google’s version really only represents one of at least four types of Search Suggest:
- Popular search queries
- Mini search results
- Index lookup (auto complete)
- Search history
And as always when you start categorizing, we need a hybrid version that combines some of the above in different variations :-)
Type 1: Popular search queries
This type of Suggest shows what other queries users have entered and it puts the most popular ones at the top. It is probably the most common version due to the fact that it was the version Google originally released. When the user picks a suggestion, the query is executed and the user ends up with a set of (hopefully usable) search results.
Search suggest of this type is especially good for:
- Facilitating novel query reformulations
- Encouraging exploratory search - the user is easily inspired to relevant searches
Type 2: Mini search results
A completely different, but also popular version of Search Suggest could be called ‘mini search results’. Actual search results are shown in the drop down menu – updated search results are shown for every keystroke, hence the nick name “instant results”. When the user picks a result, he is directed straight to the content and not to a traditional set of search results.
This type of suggest is especially good for:
- Promoting specific items or products
- Support quick and efficient search
You should strongly consider adding a link called “See all search results” at the bottom of this kind of search suggest drop down. Also, add an indication of how many results the search query will result in. User studies carried out by Vertica shows that users can otherwise misunderstand the mini results as being the complete set of results. If the product is not among the limited amount of results in the drop down menu, many users conclude, that they are not at all in the web shop.
Type 3: Index look-up (auto complete)
Index look-up or ‘auto complete’ can be confused with popular search queries, but they are by nature all different. They are look-ups in the full product catalog or database of the content presented by the website. The content in this type of Suggest is so to speak more static because it represents a dump of the product database while not being influenced by the users’ interaction with the search field. Unlike the mini results, the list is not always sorted by relevance, but e.g. by alphabet.
Index look-up is especially good for:
- Helping the user when accurate and efficient data entry is critical.
- Letting the user select from a finite list of names or terms.
- Exposing the complete catalog when other users’ search terms are irrelevant for the user. E.g. when searching for road names or zip codes.
- Exposing good search terms before you have reached critical mass in the amount of search queries your users have made. It can be first step towards a suggest that will contain popular search queries.
Type 4: Search history
It is fairly rare, but this type of suggestions can be useful if you want to support the returning visitors on your site. If you have users who log in, you can connect the history to the user profile and present the data across devices. When the user e.g. searches on his smartphone, he can see what he searched for on the laptop – and vice versa.
Type 5: The Hybrid
The four basic types of Search Suggest can, of course, be combined. And to a to a great extent, they are. With hybrid models, you can support multiple user needs at once, but beware: If the feature is not designed meticulously, it will easily be at the cost of usability. It is essential to identify what you really want to support the user in doing, and then focus on that task.
Think of these usability guidelines when you have chosen the appropriate type of Search Suggest
I hope my categorization can help you in making some qualified decisions when you develop your own Search Suggest. However, before you release it, walk through this usability check list to see if you forgot some important details:
- Performance is absolutely crucial in a well functioning search suggest – if it is too slow it will only be a source of irritation. A simple user test with a real user who uses the feature will quickly reveal whether it is useful. Expect to go for response times well below 1 second in order to get a good experience. The search engine should have fast response times but optimization of pictures is also a factor when creating a fast search suggest.
- Return key should work as submit - some users will still prefer to get a full set of results and it is important that this part of the search function works as expected. When the users presses return, the search should be executed as if the suggest drop down was not there at all. Some users does not even look at the web page when the enter their queries – so they never see the suggest drop down. Consequently, it can cause great confusion if the search is not just executed when pressing the return key.
- Support use of arrow keys - users should of course be able to use the arrow keys to navigate the drop down menu and select an item and perform the corresponding action with the enter key. If you have more than one action per line (e.g. “put in basket” and “go to product details”) you should define what is the most important action and assign that to the enter key stroke.
- Test the suggest feature on a smartphone and a tablet - very often it is more irritating than useful on small screens. Many sites choose to completely remove it because of space and performance problems on mobile devices.
Have fun developing your Search suggest! If you have experienced a useful suggest feature, you are very welcome to share it in the comments below. I would love to hear from you. Or maybe you have experienced an example of usability horror in a Search Suggest that you want to warn your fellow blog readers about? Feel free to share!