In this mini-blog series we’d like to share with you some best practices from Apptus Technologies in online merchandising and e-commerce optimisation.

The guidelines and tips are a result of the collaboration Apptus has with Baymard Institute – a global leading research organisation that is well known and respected for their competence in optimising e-commerce UX design.

#3: Base filter suggestions on query relevance

It is crucial for a really great converting site to make it easy for visitors to drill down a search result to suit their intent. Unfortunately, this is an area where many online retailers fail their audience. One of the biggest issues is that in many cases there aren’t even a lot of filters to choose from. But let’s assume that you actually have a good number of filters.

There are typically three common ways to present filters: alphabetically, in order based on number of matches, and a set logical sorting (as with sizes). All these three are good, depending on the filter itself. However, there are some really important ones that shouldn’t be forgotten - sorting based on relevance of the specific query, and personalised sorting.

In most cases, it is much better to use the query relevance to sort both filter groups and filter values.  

Filter Groups

Look at the examples below. In both cases the filter groups Price and Colour are the most relevant. But note that in the first image where we search for ‘sofa’, the relevance of the phrase and products displayed show that the behaviour of this site’s visitors indicates that Style and Number of seats are very relevant.



In the second image, where we search for ‘stuhl’ (chair), the filter Style is still relevant, but not as relevant as the filter Material. Number of seats is actually still available as a filter on the second one, but since it isn’t relevant to a chair it is way down in the list of filters.


Filter Values

When you have filters like price, size or where otherwise a logical order is natural, that should be applied. But for many other filters a relevance sort order makes most sense. Especially as in the case below, where you have so many filters that you need to hide some of them in order not to have a too-long page. 


Filters for Colour and Series in this example are sorted based on the usage/relevance of the available filters for this search result. You can see this by looking at the number of results for each filter and that the values aren’t sorted by them. In the case of colour, sorting alphabetically would make little sense, but also sorting by number of hits wouldn’t be the best option considering that there are more products in Beige than ordinary Grey and Black.

To summarise filter groups and values: make sure you have support to sort them by relevance, or even better, relevance and/or personalised. Think carefully about which sort order you should apply for each filter and let your customers do some A/B-tests.

As an example, when one of our furniture retail customers changed to a better and optimised filtered navigation in search, their overall search conversion went up an astonishing 25%!


#3 of our Search Best Practices proposes to base some filter suggestions on their relevance to the user's query and not necessarily on the number of matching products for each filter.

More best practices blog posts

In our Customer Success team, we at Apptus work closely with our customers to help them unveil the power of our product Apptus eSales and make them leaders in their market. Read earlier blog posts in the series:

#1 Use a rich Autocomplete to increase conversion rates
#2 Product thumbnails should match the variation searched for

Future Best Practices blogs will cover:

  • Search Results Should Use a 'Load More’ Approach
  • Persist the User's Search Query on the Results Page.

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If you’d like to learn more, or ask about other aspects of e-commerce sites, do not hesitate to contact us.