Participant observation, which is mostly used in the early stages of a project is rooted in traditional social science field studies. In participant observation studies the researcher spends time observing and recording the behaviour of an individual or group, "listening to their interactions and immersing him/herself in the context of the participant’s daily life"[1].

Manual observation requires observers to accurately and objectively record verbatim, behaviours or actions of subjects in seemingly mundane situations in real-time [3]. The problem is that the observers interpretation of the events they witness may influence how an action is recorded and subsequently analysed. Differences in language may also hinder accurate recording. Manual observation is, however, fairly inexpensive and can be useful in producing data from which initial conclusions can be drawn [4]. To improve the accuracy, accessibility and quality of notes taken during observations, researchers should write their notes up as soon as possible after the event; maintain continuity through a key words based filing system; and use different quotation marks to code paraphrased versus verbatim text to ensure accuracy when attributing comments [5]. See also discreet observation.

Photographic observation can provide an insight into the types of behaviour exhibited by people using products or services in the home or in public spaces in a fairly quick and inexpensive way. But, unlike video, photographs cannot show movement, so it is particularly useful to take photographs which illustrate a sequence of actions taken by the subject (see 'Eyes off road time' case study). Most mobile phones feature a digital camera and this can be a very useful and convenient way of taking photographs in public places.

Video and sound recording provides a comprehensive record which can be analysed after the event, easily reproduced and shown to participants to "act as a stimulus for conversation and interviews at the end of the fieldwork" [6].

It is important to take an ethical approach to gathering data using observational techniques, particularly if you are planning to reproduce or publish images or video footage captured at a later date. Many University's or institutes involved in conducting user research, including Loughborough, have an ethical advisory committee who can provide assistance and guidance.