Since the 1990s, a trend in the UK museum sector for developing communitypartnerships has witnessed a 'participatory drive' that aims to embrace socialdiversity by engaging communities in the cocreation of exhibitions and othermuseum work. In this context, the Internet broadly, and social media inparticular, are seen as complementary to museum processes of reciprocalexchange and public access. However, as this thesis stresses, treating theInternet and social media as complementary and convergent with theparticipatory drive in museums is assumptive and has been underanalysed, andits difficulties and complexities understated.In this context, this practicebased research carefully unpicks and criticallyanalyses naturalised assumptions about online resources and social mediapractices in museums by tracing the cultural history through which theparticipatory museum has developed and contrasting it with the much latersociology of the Internet. The participatory drive is seen to be mediated throughsociety's agencies for local governance, healthcare and education services, aswell as neighbourhood groups and families. These structures act then as abridge organising people in space and time. In turn, museums' digital practicesoften assume similar social organisation in their approach towards publicengagement. However, the distributed architecture of the Internet has the effectof compressing time with space, enabling group organisation and public spacesto bypass society's structures and instead place the individual at the centre of anetwork of relationships that selforganises according to the social capitaldisplayed in online behaviour. Accordingly, the thesis argues, there is anapparent mismatch between museums on the Web and the online public, whichaffects negatively public engagement online.By bringing Bourdieu's theories of social space and social capital into the realmof the Internet, drawing on cultural historical activity theory and reflecting on aresearch residency at the Whitworth Art Gallery, this thesis goes on to examinewhy museums find it challenging to engage with online publics. Its researchpractice aimed to 'open' the digital collections of the participating museum intothe same time and space as the online public. This included triggering, following,documenting and critically reflecting upon processes, challenges and actions ofdigital engagement and the people involved in them. The thesis reflects on theresearch practice's organisational and cultural challenges, which relate to thefact that it contradicted the museum's existing departmental organisation andsymbolic representation of public access and engagement. It goes on to arguethat when digital practices of museums are attuned to the ecology and spatialstructure of the online public, the outcomes are misrecognised as unrelated tomuseums' core practices of social inclusivity. Instead, the argument continues,museums need to open up to emerging concepts of digital public space andpublicness, in order for their digital practices to be relevant to online publics.