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Testing and evaluating

Testing and evaluating are not just a ‘tick box’ exercises at the end of manufacture. Testing and evaluation should be continually carried out and used to modify a designer’s ideas throughout the whole iterative design process, with models, as opposed to 2D drawings, used to demonstrate the functionality of the product.

It is important for a designer to test and evaluate their prototype and finished product against the by conducting a variety of tests under realistic conditions. This ensures that the product is fit for purpose and responds to wants and needs of the user. Feedback may be asked from the client, target market and other experts in the market. Allowing these groups of people to physically test the product, by handling and using it, will help in gathering useful feedback for improvements to be made.

Client feedback

A designer’s initial design may not be exactly what the client had imagined, so feedback is vital to:

• help adapt and improve the product
• have a clear idea of what the users of the product, known as the target market group, are looking for
• give the designer feedback about changes they want to be made

The client may have a particular branding style or a range of existing products that the designer needs to think about or include. As the client is paying for the services of the designer, the client’s wishes should be considered at each stage of the process.

Target market feedback

A group of potential users of the product can be given a prototype to test. These user trials aim to get honest and critical opinions about improvements or modifications needed from a range of people. Designers can then analyse the results to modify and adapt current designs and prototypes to improve the product and meet target market expectations.

Expert opinion

Professionals in industry can provide insightful and appropriate feedback. They could have experience of how to make improvements, or how a product can be cheaper or easier to make.

Analysing testing results

To record their findings, designers will take pictures and written notes from observations of users operating or wearing their product, as well as gathering users’ opinions on this experience. Observing and speaking to a variety of user groups and experts allows for more reliable and extensive feedback than that gathered when speaking to just one person.

When numerous people are asked for opinions, it is important to ask questions that can be quantified to provide information that can be analysed using spreadsheets and algorithms:

• quantitative data is information that can be measured and written down with numbers, for example length
• qualitative data is information that cannot be measured and is often based on opinion, for example favourite colour

Being able to create charts and graphs means data can be looked at quickly and can be shared with other people in a simplified form, as .

Face-to-face or more conversational interviews give designers the chance to ask questions and help users form an opinion by offering options for new iterations. This qualitative data is also useful in the analysis of prototype testing.

Evaluating against the specification

Designers will have written a design specification, developed from the design brief and based on the results of completed research. This is where a specific list of criteria is written that a designer can follow as a set of rules. During the iterative design process, this specification should be referenced to and designs evaluated against it to ensure the final solution is the best fit.

Considerations might include:

• How does the product fit within the range of sizes specified?
• Does the product fit the client’s taste?
• Do the materials and components fit within the specified cost limits?
• Does the product appeal to the target market?
• Will the design comply with current safety standards?
• Will the product have a minimal impact on the environment?

Evaluation is part of the iterative design process, a circular design process that models, evaluates and improves designs based on the results of testing.

The iterative design process works by analysing the feedback received and evaluating against the specification criteria so to determine the effectiveness of the product and consequently to redevelop the product. Further improvements can be made and then more feedback can be gathered until both the client and the target market are happy with the outcome.

Without the iterative cycle of evaluation and improvement from both the client and the target market, the product may not be the best on the market. This will allow another manufacturer to produce a better product that will be more successful.