Every year, many research projects are conducted within the field of interactive information retrieval on a broad diversity of users. Over the last few decades, an increasing number of studies have addressed user groups that may be defined as minority groups, such as people with disabilities. There is still a need for more studies on such user groups. The question, however, is how to conduct research on cohorts that might be regarded as 'vulnerable participants'. Previous research has showed that one cannot always conduct rigorous experiments for all types of users, and there are many issues to be raised in this regard, e.g ethical considerations. This tutorial addresses the responsibility of the researcher to consider how to conduct experiments where there might be a mismatch between rigour and ethics. Users with disabilities will be used as case studies, but many of the topics may have transfer value to other cohorts regarded as 'vulnerable participants'.

Many people with intellectual impairments experience challenges searching for information. Consequently, they rely on intermediaries (e.g. caregivers) to solve their information needs. In the field of IIR, little is known about this user-intermediary interaction. More empirical data is therefore needed, both to understand how to support the intermediaries and increase the possibilities for people with intellectual impairments to solve information needs themselves. In this study, 25 people working with adults with intellectual impairments were interviewed about the information needs of the end users and the routines for solving these needs. The purpose was to explore when and how the user-intermediary interaction occurred. According to this study, most end users had limited access to information sources, and relied almost entirely on intermediaries. Further, the technological skills among the intermediaries seemed to affect access to and use of digital devices. Few end users expressed information needs outside everyday life. Moreover, information needs were given very little attention and solving such needs were not part of the routines at most facilities.

Information seeking and access are essential for users in all walks of life, from addressing personal needs such as finding flights to locating information needed to complete work tasks. Over the past decade or so, the general needs of people with impairments have increasingly been recognized as something to be addressed, an issue embedded both in international treaties and in state legislation. The same tendency can be found in research, where a growing number of user studies including people with impairments have been conducted. The purpose of these studies is typically to uncover potential barriers for access to information, especially in the context of inaccessible search user interfaces. This literature review provides an overview of research on the information seeking and searching of users with impairments. The aim is to provide an overview to both researchers and practitioners who work with any of the user groups identified. Some diagnoses are relatively well represented in the literature (for instance, visual impairment), but there is very little work in other areas (for instance, autism) and in some cases no work at all (for instance, aphasia). Gaps are identified in the research, and suggestions are made regarding areas where further research is needed.

Designing user studies in the interactive information retrieval (IIR) paradigm on people with impairments may sometimes require different methodological considerations than for other users. Consequently, there may be a tension between what the community regards as being a rigorous methodology against what researchers can do ethically with their users. This paper discusses issues to consider when designing IIR studies involving people with dyslexia, such as sampling, informed consent and data collection. The conclusion is that conducting user studies on participants with dyslexia requires special considerations at all stages of the experimental design. The purpose of this paper is to raise awareness and understanding in the research community about experimental methods involving users with dyslexia, and addresses researchers, as well as editors and reviewers. Several of the issues raised do not only apply to people with dyslexia, but have implications when researching other groups, for instance elderly people and users with learning, cognitive, sensory or motor impairments.

Dyslexic users often do not exhibit spelling and reading skills at a level required to perform effective search. To explore whether autocomplete functions reduce the impact of dyslexia on information searching, 20 participants with dyslexia and 20 controls solved 10 predefined tasks in the search engine Google. Eye‐tracking and screen‐capture documented the searches. There were no significant differences between the dyslexic students and the controls in time usage, number of queries, query lengths, or the use of the autocomplete function. However, participants with dyslexia made more misspellings and looked less at the screen and the autocomplete suggestions lists while entering the queries. The results indicate that although the autocomplete function supported the participants in the search process, a more extensive use of the autocomplete function would have reduced misspellings. Further, the high tolerance for spelling errors considerably reduced the effect of dyslexia, and may be as important as the autocomplete function.