7.1 Pattern: Voice Search
7 3 Pattern: tap-Ahead
Tap-Ahead implements auto-suggest one word at a time, through step-wise refinement, creating a kind of keyword browsing.
how It works
Instead of trying to guess the entire query the customer is trying to type at the outset and offer the best one-shot replacement the way desktop web does, Tap-Ahead on mobile devices guides the auto-suggest interface through the guessing process one phrase or keyword at a time.
This is how it works: When the searcher enters a few characters, the auto- suggest function offers a few query suggestions. At this point the searcher has two choices:
■ Tap the query if it is a sufficiently good match for what she is looking for.
■ Tap the diagonal arrow on the right side of the screen to populate the search box with the query keywords, and execute the auto-suggest function again.
By giving the searcher the ability to “build” the query instead of typing it, the inter-face offers a much more natural, flexible, and robust auto-suggest method that’s optimized to solve low bandwidth and fat-finger issues people experience on mobile devices. Using the Tap-Ahead interface, customers can quickly access thousands of popular search term combinations by typing just a few initial characters.
example
An excellent example of this pattern is the Android native search (see Figure 7.6).
As you can see from the following example, the Tap-Ahead pattern offers an excellent alternative to typing longer multi-keyword queries.
7.1 Pattern: Voice Search127
Figure 7.6: The Android 4.0 Native Search includes an implementation of the Tap-Ahead pattern.
In this case, by tapping the diagonal Tap-Ahead arrow, the searcher could enter a complex query “Harry Potter spells app” by typing only four initial characters (harr) and tapping the diagonal arrow two times. The traditional one-shot auto-suggest interface is unlikely to be able to offer this entire fairly unusual phrase as an auto-suggestion, so the customer is likely to have to type most, if not all, of the 23 characters of the query Harry Potter Spells app.
when and where to use It
Use the Tap-Ahead pattern anywhere the auto-suggest is used outside a one-shot controlled vocabulary auto-suggestion and where longer, multistep, multi- keyword queries offer an advantage and create a better set of results.
why use It
In contrast to desktop web search, auto-suggest on mobile devices is subject to two unique limitations: It’s harder to type on a mobile device and signal strength is unreliable. Tap-Ahead solves both issues in an elegant, minimalist, and authenti-cally mobile way. Tap-Ahead enables the mobile auto-suggest interface to maintain flow and increase speed and responsiveness on tiny screens that is simply not pos-sible to currently achieve with the traditional one-shot auto-suggestion interface.
Is there evidence of this? The author’s field research shows that in mobile environments people often select search suggestions they do not need, just to save typing in a few characters. (Read more about this in “Mobile Auto-Suggest on Steroids: Tap-Ahead Design Pattern,” Smashing Magazine, April 27th, 2011, http://www.smashingmagazine.com/2011/04/27/
tap-ahead-design-pattern-mobile-auto- suggest-on-steroids/). Tap ahead effectively resolves this issue.
Chapter 7: Search128
other uses
For the few years that the Android platform has been around, the keyword sug-gestions have evolved from being an exact match to Google’s web sugsug-gestions to being its own mobile-specific set. Yet you can do even better in your own app by using a simple trick: Offer Tap-Ahead one keyword at a time.
The advantage of the one-word-at-a-time Tap-Ahead refinement interface is that the refinement keywords can be loaded asynchronously for each of the 10 auto-suggestions while the customer makes the selection of the first keyword. Given that most queries are between two and three keywords long, and each succes-sive auto-suggest layer offers 10 additional keyword suggestions, Tap-Ahead with step-wise refinement enables customers to reach between 100 (10 * 10) and 1,000 (10 * 10 * 10) of the top keywords through typing only a few initial characters.
Anecdotally, although Tap-Ahead is useful, few people have discovered its power to cut through tediousness and all the fat-finger mistakes associated with typing.
By offering keywords one at a time, the interface is optimized for the Tap-Ahead pattern, so discovery should increase, thereby also increasing the satisfac-tion. Tap-Ahead one word at a time is an excellent variation of the Tap-Ahead for e-commerce apps.
Pet shop Application
It’s easy to imagine Tap-Ahead being useful in entering complex keyword queries.
However, it’s not as important with dog breeds, for example, which form a con-trolled vocabulary. There is scant advantage to provide a Tap-Ahead expansion from Mas to Mastiff to Neapolitan Mastiff because there are not many queries that start with Mastiff. Instead, a simple, traditional one-shot controlled vocabulary auto-suggestion (Mas directly to Neapolitan Mastiff) is a more useful approach because it not only allows the user to pick up standard keyword queries such as English Mastiff and Neapolitan Mastiff but also an interesting keyword varia-tion Bullmastiff and category expansion Guard Dogs (see the “7.2 Pattern: Auto- Complete and Auto-Suggest” section).
tablet Apps
The owners of large tablets are generally more willing to type a longer query, and low bandwidth is usually less of a problem for them (many tablets are used with Wi-Fi only). Nevertheless, Tap-Ahead is no less useful on tablets, where less work is perceived as a good thing and tapping a suggestion is as easy as tapping
7.1 Pattern: Voice Search129
the next character on the touch keyboard. There is also early evidence that tablet queries are slightly longer, which also speaks in favor of keyword browsing.
caution
The best auto-suggestions on a mobile device come from a database that’s differ-ent and distinct from the web auto-suggestions database. This is especially true for Tap-Ahead implemented one keyword at a time—but that’s how important this function is to creating an excellent search experience!
At this point it’s not clear who, if anyone, holds a patent on this functionality.
Google began using it first in its general device search and Google App for iPhone;
although it is not used for single keyword browsing as of the time of this writing.
Microsoft and Apple are both likely actively pursuing similar patents.
related Patterns
7.2 Pattern: Auto-Suggest and Auto-Complete