The goal of a web usability study is to make sure a web site’s information and user interactions are easily accessible, written instructions are clear, options and interactions (buttons) are unambiguous and obvious.

We will in this blog post discuss the significance of eye tracking for web usability, the cost of hardware and return on investment (ROI).

The ROI is considered on two levels:

1.    The usability consultancy company – what they should consider when adding eye tracking capability to their existing service catalogue.
2.    The end client – when he buys usability consultancy, can he expect to get a return on investment?

Web usability has proven its value within a broad range of studies on web applications. First and foremost e-commerce benefits from optimal usability – a non-usable website means losing business; the popular example: if people cannot find the buying button they cannot buy your products. Even worse, the frustrated user might head directly to the competitor’s site to do their purchase. Another important application of usability research is to optimise communication between an organization (government or company) and its users (citizen, customer) – make sure the user finds the needed information by own force which potentially can reduce expenses for face-to-face communication or telephone support.

According to Jakob Nielsen [JN] these are the typical metrics being optimised in usability studies:
–    Conversion rates
–    Traffic numbers
–    User performance
–    Target feature usage

Seen from the end-client perspective maximising any of these parameters is what would eventually result in increased web site use, turnover, reduced support or any other cost or revenue related optimisation. Thereby it is in principle possible to calculate the return of investing into a usability study. Calculating return on investment reliably can be straight forward [RB] (although it is not always obvious what to consider in the calculation [DR]). Research has shown that often usability studies can have ROI anywhere between 100-1000% [JN].

Eye tracking based usability testing of web sites will rarely be used as a standalone method, rather the combination of several methods will add up to the final recommendation presented to the end-client. A usability researcher might consider using eye tracking always, sometimes or only whenever the client asks specifically for it. For the usability research-agency the eye tracking capability adds value on two dimensions:

1.    It offers a tool that can answer questions no other method can answer.
2.    It gives a competitive advantage – by attracting the interest of potential clients.

However what is this worth in terms of securing existing revenue or growing business? How can the usability agency assure that investment into eye tracking hardware and software is returned?
Before making a purchase of hardware to support the eye tracking capability its useful to consider the available options, to know better what is the relation between price and technical configuration of the eye tracking platform.

There are several companies offering mature eye tracking hardware platforms. On the premium end we have Tobii and SMI recognized by the systems’ ability to track well above 90% of the population. However that trackability comes at a cost. Making a small compromise on the trackability there are cheaper alternatives; worth mentioning are EyeTech Digital Systems and Mirametrix. The gaze coordinates accuracy of these systems are almost comparable to the Tobii system, still plug and play and easy to use [IMO].

Furthermore web usability does not require hardware with high sampling frequency i.e. above 60 Hz, actually between 30 HZ and 50 Hz would suffice. This is acknowledged by Tobii who recently released the X1 eye tracker with 25-30 Hz sampling frequency.

Eye tracking based usability studies are often qualitative in nature, which is reflected in the generally low number of respondents in a particular study compared to what is the standard in eye tracking for market research [JL]. In a usability study testing as little as one respondent can deliver value. Hence the trackability is not of great importance, low or medium priced eye tracking systems are perfectly suitable for usability research, as long as the gaze accuracy is high.

Using low cost systems for usability studies on web sites makes it much easier to generate ROI. Actually the difference between the high and low price for eye tracking equipment is so high it defines the gap between an investment and a standard IT/tool purchase. An investment requires careful consideration of cash situation, strategic direction of the organization, risk etc, while a standard purchase can be motivated by a simple wish to try out something new, add an item to the existing service catalogue and make the clients happy.

Further Reading
[JN]   Jakob Nielsen
[RB]   Randolph G. Bias “Cost-Justifying Usability”
[DR]   Daniel Rosenberg  “The myths of usability ROI”
[JL]    James R Lewis “Sample Sizes for Usability Studies: Additional Considerations”
[IMO] Attention Tool Hardware Options