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Accessibility and usability issues for on-line questionnaires and interviewing tools
By Katrina Hands, published 3rd May 2004.
On-line questionnaires and interviewing tools are being used increasingly in a wide variety of contexts, such as recruitment, health and finance, so are likely to be used by individuals with varying computer expertise and interaction requirements. In order to maximise the number of people who are able to complete the questionnaire or interview, it should:
- be quick and easy to use
- move seamlessly from one question to the next
- provide an estimate of completion time
- be readily accessible to the target audience
Speed of Loading
When developing a questionnaire or interview, speed of loading is considered to be particularly important, as having a continuity of flow is essential to the interview process. Research regarding response times has found that advice has changed little since Robert B. Millar presented a paper on the topic at the Fall Joint Computer Conference in 1968 :
- 0.1 second is about the limit for the user to feel that the system is reacting instantaneously.
- 1.0 second is about the limit for the users' flow of thought to remain uninterrupted.
Care should be taken to ensure that, as far as possible, the loading time for each page in the interview system is less than 0.1 second and this should be tested using modems of varying speed. It is acknowledged, however, that this cannot be totally controlled due to varying performance of different internet service providers (ISPs).
Use of a simple interface for the delivery of the computer interview is recommended. A cascading style sheet (CSS)  should be used to give consistency of appearance throughout the interview and to draw the interviewees' attention to important information on the screen. The use of a linked, rather than an embedded, CSS will also serve to improve the page loading times as a linked CSS need only be downloaded once for the entire site.
The means of navigating through the computer interview should be simple and obvious. Be aware that users may use the toolbar navigation buttons in addition to the navigation options provided within the computer interview. It may, therefore, be necessary to consider implementing a specialised browser window which provides limited toolbar options; however, careful consideration must be given before utilising this option. It is stressed that if a new browser window is to be opened then the users must be given prior warning, particularly if it a customised browser window.
Inform the Users
The users of the computer interview should be given an indication as to how long the computer interview is likely to take. While it is useful to provide this information at the start of the interview, it is also very helpful to inform the users during the interview as to how far through the interview they are. This can be done graphically or by simply giving the number of questions still to be answered.
The interface should also indicate clearly to the users when they have moved on to a different question. Experience has shown that if the computer interview flows very smoothly between questions then users may not instantly realise that they have moved on to a different question.
In order to make the questionnaire or interview accessible to as wide an audience as possible, care should be taken to ensure that users can interact with the site using a variety of options, such as a mouse, a touch screen or the keyboard. It is essential that interviewees can carry out the computer interview independently, as privacy is important in eliciting the most honest and open answers as possible.
It is also highly recommended that the site is checked to ensure accessibility using the available on-line tools, such as WAVE , the World Wide Web Consortium's HTML Validator  and the Vischeck website , where it is possible view to the developed web pages whilst simulating certain conditions of colour-blindness. Use should also be made of speech and text only browsers to ensure that the interview can still be carried out.
Users should be guided through the interview using simple navigation options and constantly informed as to how far through the interview they are. Extensive testing is essential to ensure that the interview can be carried out independently by the target users. It is vital for the interview delivery system to be quick and easy to use; otherwise there will be a high number of incomplete interviews.
- Nielsen J. Usability Engineering, Academic Press Ltd, 1993