Issue 55

How to evaluate design deliverables

Mihai Varga
Design Lead @ Interface-design.co.uk


Wouldn't it be wonderful if there were a standard for evaluating design deliverables? It would make everyone's life easier: designers, project managers, clients. Good-bye complicated discussions! Well, even if there is no magical formula, this article gives an overview of criteria that help to evaluate digital design deliverables.

The way people relate to design can make the process of digital product creation difficult. Design seems to be subjective and esoteric. Further, some people believe the myth that having seen many designs makes them experts. In reality there are empirical and pragmatic principles that form the basis of good design.

It may be utopic to imagine a world in which all actors involved in the design process can rely on common frames of reference - the field is not mature yet. However, there are principles that once understood can help to guide things in this direction. Even if the designer is the only one who uses these criteria, the deliverables will reach a higher quality level and design decisions can be supported by better arguments. If the project manager joins the dance, she can defend designs and explain design decisions in a more persuasive way. If, finally, clients were to be educated, discussions can be much more productive and revolve around those things that can improve the product.

The criteria will be explained with designs for digital interfaces in mind, but the same framework applies to webdesign, with some amendments as will be shown.

Any design deliverable must satisfy three criteria: it has to be functional, aesthetic and it must produce the desired psychological effect.


The principle difference between design and art is that design serves a purpose. When it comes to a digital interface, the product owner dictates the purpose. However, this can lead to the user being reduced to a second order priority. In fact, designs should serve users.

For the user needs to be taken into account during the design process and for the deliverables to be evaluated with the user needs in mind, they have to be made explicit. Further, they must be ranked in a hierarchy.

Thus, when evaluating a design deliverable, the first question to ask is: when the user has contact with the interface, does it respond to users' needs using the simplest interaction? Intermediary steps that increase response latency can affect how this criterion is satisfied.

Responding to user needs entails that user behaviours have been predicted and that the user does not have to search for a solution, but rather the solution is readily presented in the interface. Things are intuitive when the users don't have to wonder "how do I..". However, intuitiveness in interfaces comes about through a rational process that relies on identifying needs and predicating likely behaviours.

Further, for a design to be functional, it has to offer solutions to all users. This can be difficult to fulfill when some user types have been ignored. Clients usually have a productive imagination when it comes to user types. When some of them have been ignored, designs will be rejected by clients and rightly so.

When it comes to web sites, the functional criterion is as important, but it may be more difficult to tell what the users need. Although it is a persuasive discourse, websites must respond to questions users ask and to the worries they may have. When a website gives a satisfactory response to all these, in the right order, it can be called functional.


Functionality is not sufficient. Long gone are the times when an application could get away with a functional but upleasent interface. People deserve aesthetic applications and they outright demand them.

For a design to fulfill this criterion, it needs to be consistent. Style elements must be used in a harmonious way. The human mind loves to look for patterns and to find them. When a design has order, it is one step closer to being aesthetic. Coherence is given by the concept that forms the basis of the design and by the degree to which this concept is being contradicted throughout the design or enforced.

To help with coherence in designs, grids are critical. Absence of a grid will always lead to aesthetic problems. Grids organize the composition, which has to be permeated by a sense of harmony with individual elements leading to a coherent whole.

Further, aesthetics are marked by trends. A design that is not contemporary may be perceived as being unpleasant by users. Expectations are not met and users will draw inferences about the performance of the application, be they justified or not. However, truly aesthetic designs are timeless. They don't just avoid styles that are out of fashion; they also avoid the ones in fashion. The same applies to cultural variations: designs that transcend these variations are more aesthetic overall.

When it comes to web sites, trends are more volatile and sometimes it is more important to be trendy than to be timeless. It all depends on the brand image that must be created.

Psychological effect

Interactions have a psychological effect on users: they result in emotions and thoughts. They don't have to be extreme to be important. If a design is functional and aesthetic, it probably won't cause rage and hatred, but a good design should aim higher than simply avoiding frustration.

Designers and stakeholders should ask questions such as: what emotions does this design stir up in people as they use the application? What about after they have used it? What thoughts should they have about this interaction?

Sometimes a designer may want to raise the level of emotional activation to increase attention, while other times she may want to reduce it to a minimum. Sometimes the aim is to change the mental state of a user, while other times it is the opposite.

Elements such as harmonious use of colours, the dynamic or animated character of the interface and styles have a psychological effect. However, content also makes a difference as it can result in negative emotions. It also works the other way around: the emotional state the user is in, can affect how content is being processed.

In websites the brand personality is what determines the goals of the psychological effect to a large extent. This has an implication for purchase decisions. Even when a website works well on a functional and aesthetic level, it stands a fair chance of failing if the psychological effect is not right.


Evaluating designs based on these criteria helps to identify those things that need to be changed to improve deliverables but it also brings clarity into the thought process and into meetings. To address each criterion, questions can be asked and if deliverables don't meet expectations they can be improved.



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