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Articles

Part-time learners in open and distance learning: revisiting the critical importance of choice, flexibility and employability

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Abstract

In this article, we argue that, if open learning seeks to (re)assert a social justice mission, issues of openness and flexibility are more critical than ever. Drawing on qualitative data from a National Union of Students Wales/Open University study, which explored, in the voices of Welsh students, the identity, motivation and barriers faced by part-time distance learners, three key findings emerged. First, the chimaera of ‘choice’ – for part-time distance learners whose personal circumstances prevent any other mode of study; second, the vacuity of policy assertions around ‘flexibility’ in HE – what personalised learning means for part-time distance learners should be contested and re-examined; third, the mantra of ‘employability’ – for part-time distance learners, employability is a conundrum which needs to be understood in a far more inclusively nuanced way. We conclude that the voices of part-time distance learners need to be heard by policy makers and should inform open universities’ continuing efforts to enable vulnerable and marginalised learners to access HE.

Introduction

In 2010, this journal dedicated an issue to the relationship between openness, access and e-learning. In a key editorial, Gaskell (Citation2010) asked ‘Does e-learning promote inclusion?’ Drawing on early analyses around open educational resources, Gaskell equated the empowerment of individuals not ‘affiliated with formal educational programmes’ (Wiley & Hilton III, Citation2009) with the social justice agenda that first inspired the development of ‘open learning’. It is to this social justice issue the authors wish to return. We question the extent to which barriers to learning have been sufficiently addressed, to say nothing of ‘overcome’, by a distance learning paradigm in which enabling people to study anywhere, and at a time to suit themselves, is ‘enough’ to address learning inequalities. We argue that the potential for open/distance/e-learning remains only partially fulfilled in terms of enabling access to higher education (HE) for disadvantaged/excluded groups and that the prevailing focus on technological infrastructures (and the current sector hysteria accompanying MOOCs) is too narrow to meet learner needs. Warschauer (Citation2003, p. 216) talked about the need for the use of ICT in education for meaningful ends, to reduce ‘marginalisation, poverty and inequality and enhanc[e] economic and social inclusion for all’. We concur with this laudable aim, but argue the individual learner voice of the student for whom part-time study at a distance is the only option (HEFCW, Citation2014), is a crucial missing dimension which requires prioritising in any debate about openness.

We frame this article in terms of Tait’s (Citation2008) rhetorical question (again in this journal) ‘What are open universities for?’ His answer emphasised the mould-breaking tradition of innovative institutions using ‘distance’ in radical ways to improve openness, as highlighted by Harold Wilson (UK Prime Minister at the time the OU first opened its doors): ‘the aim … is to widen opportunities for HE by giving a second chance to those who can profit from it, but who have been, for one reason or another, unable to go to a university … on leaving school’ (Wilson, Citation1971, p. 534). Nonetheless, Tait reminds us:

It is important to remain sensitive today to the possibility that distance learning continues to offer opportunities that are difficult to succeed with for so many ...because of the inherent difficulty of part-time distance learning … [and] the engrained disadvantages of non-traditional educational backgrounds in all their complexity …(Citation2008, p. 87)

One-third of undergraduates in the UK (600,000) study part-time. Ninety per cent of those are mature students, and the Open University has a significant impact on the shape of part-time provision across the UK (Department for Business, Innovation and Skills (BIS, Citation2012). In considering the challenge to succeed for those part-time adult students without conventional educational qualifications, the function of open universities to ‘widen access to new groups of students’ (Perraton, Citation2000, p. 90) is refined by Tait (Citation2008) as ‘providing individual opportunity and social justice that the HE system cannot or will not satisfy because of its own interests or limited vision’ (p. 92). In this context, it is worth re-stating the OU’s openness in terms of having, generally, no entry requirements for its undergraduate programmes of study: a risky agenda informed by values which run counter to prevailing orthodoxies around a marketised HE sector. We propose the insertion of part-time distance learner voices to remind policy makers of the kind of barriers which continue to limit access to HE and to strengthen the discourse around openness in HE and social justice.

This article draws upon qualitative data from an NUS Wales/Open University collaborative study investigating the experiences of part-time HE learners in Wales. That study focused on who part-time students were, why they chose to study part-time, and what barriers they faced: Wales offered an interesting case study as a nation with significant areas of rural and post-industrial deprivation, and thus a setting in which part-time distance learning might provide opportunities for adult learning unmet by traditional face-to-face HE. The contextual backdrop for the study was around three specific issues: first, falling UK part-time undergraduate enrolments, consistently in Wales (24% over the period 2007–11 [Rees & Rose-Adams, Citation2014]), albeit not as steep as in England (40% between 2010–2011 and 2012–2013 [Universities UK, Citation2013], where the spike in tuition fees which followed the 2011 White Paper Students at the Heart of the System (BIS, Citation2011) provoked anxiety across the sector); second, an unhelpful state of flux and uncertainty in the support arrangements for those studying part-time (Heller & Callender, Citation2013); third, in the disparate funding for HEIs which offered little incentive for sustaining part-time provision (Universities UK, Citation2013). Crucially, in the UK in general and even in Wales, where part-time HE was prioritised (Welsh Government, Citation2013), there was a recognition that discussion around the purpose and benefits of part-time study had been crowded out by a shrill policy discourse valuing only full-time HE, leading to a knowledge gap in relation to the experience of part-time distance learners, especially those from what might be termed a widening participation background (for example, economically disadvantaged adults, those with few prior qualifications, those with a significant gap since previous educational study, and those balancing study with work and/or caring responsibilities).

In Wales, part-time HE is recognised as an attractive option for some of those students – in other words, learners from what has been in England termed a ‘widening participation’ background. The quantitative survey data from the original study has already been reported as It’s About Time (Rees & Rose-Adams, Citation2014), concluding ‘Part-time opportunities are at the forefront of widening access and employability in Wales … widening access is about offering every person, regardless of circumstances, the opportunity to a higher level learning experience that is appropriate, relevant and valuable’ (p. 26). Here, we draw upon the interviews with part-time distance learners in Wales, conducted to complement the survey data, to argue that the voices of individual students, those for whom distance learning is the only option given the personal barriers faced, is missing both from the discourses around Open Learning theory and practice, and from broader policy debates about access to HE.

Methodology

In seeking to elicit ‘hard-to-reach’ student voices, the study drew on a purposive sample of 20 part-time learners in Wales studying Open University courses at a distance. The interviewees had identified themselves in the national survey as willing to be contacted for follow-up questioning. Semi-structured telephone interviews were conducted in Autumn 2013 by two consultants. The interviews were framed as offering the opportunity for in-depth exploration of individual experiences and perceptions of part-time study, with personal circumstances emerging from narratives offered, rather than prompted directly. Interviews were recorded and transcribed. Analysis was conducted by the authors using grounded theory methods (Glaser & Strauss, Citation2009) in order to enable key themes and individual voices to emerge. For this article, we excluded the small number of additional interviews with other part-time students at non-OU Welsh institutions, in order to present a coherent case study (Yin, Citation2009) of distance learners.

Respondents were given pseudonyms to preserve anonymity. While the majority were female, a broad age range (mid 20s–70) was represented, and voices ranged from those embarking on their first ever taste of HE on an Access course (L3/4), across those part-way through an OU degree, to one returning to study at Masters level (L7).

Findings

The voices reported here (some of HE’s most vulnerable and hard-to-reach groups, often isolated, remote rural learners) speak powerfully about their personal learning experiences, their individual learning journeys in which part-time distance learning was recognised as their only option. Emerging from the data were a series of three related themes which offer an authentic counter-narrative to some of the prevailing debates around part-time and distance/e-learning HE policy – issues to do with choice, flexibility and employability. These themes are potentially powerful drivers in re-theorising our understanding of part-time distance learners, given their expression by individuals who have overcome enormous barriers to become students. First, and most significant, was the issue of students having no choice in mode of study: this emerged from a reiteration and amplification of the impact of the wide range of personal circumstances which necessitated part-time distance learning as the sole HE study option. The second theme was a reminder that flexibility is the most crucial element of part-time distance learning: this emerged from a range of student voices emphasising that flexibility requires ‘open’ institutions to operationalise a highly responsive and personalised approach to meet the needs of learners. The third theme challenged those sector mission statements which blandly assert employability as a key purpose of university study: students interviewed expressed a more nuanced understanding of the alignment between part-time distance learning and employability, suggesting that a fully inclusive discourse needs to be adopted to encompass a wider range of individual employability aspirations, dependant on personal circumstances.

Part-time distance learning: the chimaera of choice

I’m working hard thank you, but I have to fit it round another life. It’s the problem of being part-time. (Bella)

It might be unsurprising, but its importance needs underlining, that studying as a part-time distance learner is the only (and therefore) necessary choice for many students on Open University modules. This was a strong message in this sample: for the students we spoke to, part-time distance learning is not an ‘option’ to be measured against full-time face-to-face study – it is that mode or nothing. For policy makers and learning designers, the privileging of full-time face-to-face campus based study for 18- to 21-year-olds as a paradigm of HE, exemplified by prevailing conceptions of HE outreach programmes as those working with local schools and colleges, simply excludes potential students for whom that opportunity has passed, or was never practicable in the first place. Conceptions of choice for part-time distance learning students are less to do with selecting from a wide range of possible study choices in terms of where, when and how as faced by full-time 18-year-old university applicants, but more to do with fitting in to the only ‘choice’ available to them.

The qualitative data from this study reveals a very wide range of reasons for students only being able to study part-time at a distance:

I have six children, five living at home … my eleven year-old has chronic fatigue syndrome and he’s borderline Asperger’s syndrome … my husband is virtually disabled … I’m diabetic and I have macular degeneration in one eye … I dropped out of A levels because I was in care and at eighteen they could no longer look after me …(Amanda)

Or

I was made redundant and given early retirement … and I’ve still got youngish children and one of them has become severely mentally ill and I spend a lot of time caring for him. (Christopher)

Part-time distance learners in this study expressed formidable and varied time pressures to overcome around studying – whether in the demands of caring for disabled partners and children while studying: ‘My husband is disabled and has hospital appointments, I have hospital appointments, one of my daughters has hospital appointments’ (Amanda), or in balancing intensive work pressures (whether part-time or full-time), voluntary work and family commitments (caring for elderly relatives) while studying (Bella) or ‘being disabled, I have to balance my voluntary work and care for my children and have to use all my spare time for studying’ (Sarah). Others had to fit study around three or four part-time jobs, with working ‘odd hours’ (Rachel) presenting a particular challenge for anything but the most flexible study patterns. Such quotations encapsulate the urgent need of flexibility being designed into course design and delivery as both temporal (choice of when to study) and geographical (choice of where to study) if open learning is to address social justice.

Cost is also a limiting factor: for one interviewee (Ruth), working full-time in a ‘very stressful job’ and with two children not only meant any traditional HE was ‘out of the question’, but even the possibility of part-time study was only opened up by fee waivers (‘Tesco Clubcard vouchers initially meant the first two modules were affordable … if the cost of modules goes up, like in England, that would be a problem for me … I guess I hoped to go on further, but I’ll probably not be able to if the costs increase’). Another student, working as a freelance consultant while juggling ‘lots of taxiing for two sporty children’ (Sandy) admitted:

financially I could only do it part-time, I couldn’t take 12 months out, I am reliant on my income … in the future, I could see myself trying to do some other learning, but I would be hard-pushed to justify the cost and time at present.

For Simone, study has to fit around working full-time and running a part-time business, and ‘could only be part-time because I need income to pay the rent’. We wonder if open learning is sufficiently open to those without spare economic resources?

Health issues were also raised (although it should be noted not in any sort of defensive ‘victim’ mode, but in describing the realities of life as a part-time distance learner): whether in studying while coping with long-term mental health problems (which had originally prevented university attendance at 18), manifested when a student feels fine one day and is unable to do anything the next: ‘I’m on medication for treatment of depression and anxiety … a lot of the time I find it difficult to go out of the house …’ (Luke); or in embarking on HE study following a recent diagnosis of MS (causing work to be given up) when the stress of managing hospital appointments and physiotherapy has to be balanced against studying in relation to the personal concern that ‘my personal horizons will get very small … if I don’t do it now I am never going to do it’ (Michaela); or in being housebound and thus unable to consider face-to-face HE (Greg), or when poor health (mobility issues) ‘dictates part-time study’ (Sarah).

For others, the juggling of study with full-time work and a new baby is worth it now that previous ill-health has been overcome, ‘I have the brains, it’s just a slow process doing it part-time … getting to any face-to-face study would be hard … missing out at 18, I never thought I could afford to go to university, but I can’t afford not to work’ (Sharon). Or the student who:

planned to go to university at 18 from school, but the combination of health issues and hospital appointments prevented it – I chose part-time because I didn’t want to overwhelm myself … see if I could juggle … my illness fluctuates up and down … studying at sixth form college was very structured and it was difficult to fit my health issues around. (Teresa)

Another student’s part-time study patterns were affected by health: ‘I study late at night as steroids make me hyperactive’ (Simon, a career, semi-retired through ill-health).

Others explained the impracticality of studying full-time or face-to-face when having to make decisions about attending tutorials by public transport and living remotely from other students: ‘I live in a rural location in mid-Wales … I have elderly parents who I visit quite regularly … tutorials are a three hour journey to get there in an evening’ (Julia) or ‘I don’t drive because of my medication … and I live in a rural area – you can’t get into university for class times on public transport’ (Luke). For self-employed students, part-time was the only possibility, and even start dates ‘had to be fitted around work pressures’ (Sally). For other individuals, studying was viewed as a hobby by members of their family and was done when others’ needs were met (Christopher).

Time pressures (time poverty) were perceived as impacting on both learner engagement and assessment performance. Allied to this, health issues and transport costs increase the challenge faced by individuals of financing HE study, so part-time distance learning was not only the sole practicable study option, but was also the only economically feasible option for students in our study. Such examples of highly personal autobiographical perceptions and descriptions are important as challenging any notion that policy makers can continue to adhere to a homogenous composite of the part-time distance learner, to the extent that ‘the part-time market risks operating in neither the interests of students, employers nor the economy’ (Universities UK, Citation2013, p. 1).

Part-time distance learning: the need for more flexibility?

If the OU didn’t ‘accept’ my mental illness, I would have found it a lot harder … (Gemma)

There is a small irony that part-time distance learning continues to be considered as a necessarily, and inevitably, more flexible study route than full-time face-to-face HE. To some extent it of course is – students do not need to ‘attend’ face-to-face, and can study (within the limitations of assessment deadlines) at times to suit them. However, it is also apparent that more and more ‘full-time’ provision (however that is interpreted) is increasingly adopting a blended approach to offer pedagogic flexibilities (McClinden, Citation2013). Proponents of flexibility (Barnett, Citation2013) seek institutional change in relation to more flexible systems and pedagogies, whether those institutions’ values are market-driven or mission-driven. But the extent to which such flexible approaches are sufficiently personalised and responsive to the range of students’ individual circumstances that impact on their study and support needs is far from clear.

So the distinctions are becoming blurred – other than in fee setting of course. But data from this study suggest that a clearer understanding of flexibility is required in the sector, one which addresses the wide range of barriers to study faced by individual students: ‘I had to give up work about two years ago, I have MS and I’m a full-time wheelchair-user … it’s pretty full-time, with hospital appointments and doing physio every day’ (Michaela).

Barriers to HE entry remain significant disincentives. One student’s story is familiar from adult education autobiography, but is nonetheless instructive of the need to revisit openness: ‘I left school when very young with no qualifications (so traditional university was not possible) and subsequently I have needed to keep working … I was very new to studying, absolutely raw, I had never even planned an essay’ (Rachel).

Flexible support is crucial in such situations, but while some students found peer support through day schools or tutorials helpful (despite or because of their study isolation), many students felt excluded from accessing these due to a combination of time, distance and cost. Although some mentioned support provided by online student forums, most did not rely on these, either because of poor broadband internet access (associated with rural locations), or because they were put off by the competitiveness or ‘obnoxiousness’ (Sharon) of some student comments and, being socially anxious, coped better studying on their own.

For many of these isolated students, it was the peer-initiated Facebook groups which were reported as beneficial in terms of supporting continuance of study: ‘with Facebook, you get a reply within 10 min to a query, with a broad spectrum of replies … it gets you thinking’ (Luke). For others, the intense level of physical and technical support needed to enable study to occur at all was much appreciated – this kind of disabled student allowance-funded study facilitation, whether through the provision of speech recognition software to address intermittent writing/word processing problems, or the availability of a learning mentor once per week to organise a student’s study time, was considered crucial.

Inflexible barriers resulting from time pressures (especially at assessment points) can increase the stress of juggling competing priorities (i.e. the balancing act itself is precarious – ‘there are a lot of pressures with work, with family commitments, trying to fit everything in …’ (Julia). Aligned to this is the suggestion that distance learning tutors themselves need to be flexible and not assume studying has to be done in a certain way: ‘Because I am not in a 9–5 job, it is more difficult to fit study around it … there is a conflict if I have a commission to finish, and if I am working away, I am in my camper van so internet access is difficult’ (Sally).

Health barriers again came through strongly in participant comments, suggesting HE providers need to accept the study implications of (say) mental illness, and offer patience as much as flexibility. Key points include recognising the disruption caused by ‘juggling study and doctor’s appointments’ (Teresa) or the obvious but crucial point: ‘I find it much easier to study when I feel well enough to do so, rather than missing set times when I am not well … face-to-face would be more difficult’ (Sharon).

A key conclusion appears to be a perception that, because students’ time was so limited ‘study suffered’ (Sandy). Students with a range of personal responsibilities requiring flexible approaches to study often emphasised the difficult decision to commit to starting HE study, given that circumstances meant it was ‘never a good time’ (Julia).

Flexibility needs to take account of how and when students access part-time distance learning HE, recognising the wide range of learner diversity found even in this research (including potential barriers to be overcome resulting from age, disability/health problems, role as parent/carer, working part- or full-time including volunteering, or looking for employment). Perhaps notions of flexible part-time distance learning need revisiting in the context of access and inclusive approaches to HE: ‘I live remotely, in a rural area … I am juggling my father’s death and a relationship break-up … I can’t really afford the time or the money to study full-time’ (Mark). For many students, barriers exist in near-toxic combinations, and as a consequence, open universities need to be dexterous enough to adjust the intensity of study to meet individual needs.

Part-time distance learning: the conundrum of employability?

HE study has made me feel like I’m achieving something, avoiding the spiral of not feeling worth anything if I’m not working [while on medication] … people said my life was over when I had children, but I really wanted a degree, even though I know in this day and age it doesn’t guarantee a career or a job. (Luke)

Access made me get back in the mind-set that despite being stuck in a dead end job I could achieve things. (Simone)

It was particularly striking that, grounded in these data, was a commitment from part-time distance learning students to enhancing their employability through HE – but that the notion of employability they discussed was one informed by personal circumstances and personal values rather than the language of government diktats: ‘I’m not aiming for a career as an 18 year-old … it’s a different process being part-time … there’s an attitude that I’m dabbling but I’m not’ (Bella). Many comments were around the skills for/in employment agenda, but some were noticeably ‘values-driven’ (Gerwyn), rather than in relation to pure careers goals. So students talked of not being a burden, of ‘doing something worthwhile … I don’t want to be sat at home doing nothing’ (Amanda), of ‘possibly improving my career when I graduate … I didn’t want to do the same job I was doing for the next 40 years … have more options open’ (Sharon), of ‘I want to have a career in the future, so taking steps to get there’ (Teresa).

Others talked passionately about a long-term aspiration to help others with similar circumstances and characteristics to their own: ‘I want to go into mental health work … I was told I had post-natal depression and I was bipolar and there was absolutely no help for me’ (Gemma), or ‘aspiring to work as an adult education tutor, sharing with others what I have learned myself’ (Michelle).

A significantly different perspective was voiced by those students who sought to develop self-organising skills valuable for potential self-employment:

Employment would be brilliant, but because of my health and the stigma … I don’t like to set myself unrealistic goals … so in the medium term I am looking at self-employment … in the current job market I won’t have to justify myself to anyone. (Luke)

Or those acknowledging a personal drive to move on: ‘being bored with being in an entry-level job, so a stepping stone into getting a better career and improving prospects’ (Sharon).

Some students talked of positioning themselves for a ‘late career change … in a few years’ time, when I want to change jobs I think it’s going to be a useful tool’ (Julia), or of ‘not wanting to stay in the same job forever … People say what have you done this degree for? I’ve done it for me, not looking to change jobs or anything … see where it takes me, see if it opens up doors’ (Michelle). Others were very consciously preparing themselves to take up employment at an opportune time, as circumstances allowed: ‘I want to use my degree, once I’ve got it … in the future, once my son’s at secondary school’ (Margaret).

Despite the barriers reported by individuals in this series of interviews, it was striking how often highly personalised skills like resilience and persistence underpinned transformations into potential employability: ‘The OU has changed my life, my confidence levels, I wanted to prove to myself I could do it’ (Rachel), or ‘courses have opened up a different way of seeing things, which has given me a sense of achievement and confidence in myself’ (Michelle). A number of students were ‘studying for self-improvement … were motivated to finish’ (Sandy). Sharon was determined to study as ‘due to a period of unemployment and temporary ill-health I didn’t like to do nothing … I am motivated to better myself, studying things I want to study I am more inclined to stick with it’. The boost to perceptions of an individual’s own value is significant: ‘I’m impressed with myself if I’m honest … I’m not a confident person, I think I don’t deserve to do well … it is convincing myself that I can do it … the marks help!’ (Gemma).

Pegg and Carr suggest that part-time and distance learners often ‘positioned themselves very specifically in terms of their engagement with the fields of learning, working and personal life’ (Citation2010, p. 88) and found that ‘learners already both problematised the idea of graduate employability and adopted a critical and reflexive approach to their own learning’ (Citation2010, p. 89). These part-time distance learners, with significantly different (and highly personal) conceptions of employability than 21-year-old graduates, appear to embody Bridgstock’s view that the vital aim of employability policy should be to support ‘graduates to proactively navigate the world of work and self-manage the career building process’ (Citation2009, p. 31).

Conclusion

Because I took a break from studying, it did knock my confidence a bit – but it’s been good since I started this course, there is lots of validation about how you are doing. (Teresa)

I would have found it hard to imagine myself studying at this sort of level … it’s challenged me … there is a massive amount of satisfaction from doing it … things I got out of it I never thought I’d be able to do. (Julia)

The voices of these part-time distance learning students, disadvantaged, under-represented, or otherwise marginalised by their circumstances, crave parity and equity for part-time HE. For such students, it is part-time or nothing. The open and distance learning communities need to remember that their part-time provision is persistently at the forefront of enabling vulnerable and hard-to reach individuals to access HE – a critical social mission and one recalling those radical disruptions envisioned of early open universities.

However, although part-time study at a distance offers the only viable route for many students to access HE, the importance and extent of flexibility cannot be taken for granted. Student voices heard in this study described flexibility in terms of their own specific circumstances, which were often complex and challenging. Distance and open HE providers must continually re-assess the extent to which the flexibilities they provide are sufficient to support successful outcomes for diverse learners. Yorke and Longden (Citation2008) recommend programmes of study that are not just cut-back versions of full-time offerings, with adequate administrative and academic support services available where and when part-time students need them. The students heard in the present research speak to the need for institutions to maintain the highest levels of responsiveness in order to adequately support their students.

A key finding from this research is that the most disadvantaged students accessing HE through part-time distance learning understand the value of employability skills, but on their own (highly contextualised) terms. National policies for employability which focus on graduate outcomes for the traditional school-leaver, (the 21-year-old graduates) will inevitably fail to capture the nuanced experiences and career plans of students who do not fit that standard mould, and in so doing, fail to achieve the ambitions for a responsive workforce serving the needs of the economy in a competitive global marketplace, by marginalising many who would otherwise make a strong contribution. Open universities need to develop a far stronger advocacy role on behalf of the kind of student voices reported here and to ensure that issues of choice, flexibility and employability in HE are understood by policy makers in a far more inclusive way than at present in the UK.

Notes on contributors

John Butcher is the deputy director of Access and Curriculum at the Open University, UK. He has recently led a research project on part-time learners across the UK, and previous projects include inclusive assessment in HE and learning through partnerships in HE. He has published numerous articles on academic development and mentoring in HE and post-compulsory teaching skills. He is the author of Developing Effective 16–19 Teaching Skills and co-editor of Leading professional Development in Education. He has supervised and examined many doctorates, and served as an external examiner at a number of universities.

John Rose-Adams is Strategy Manager at the Open University, UK. He has published articles on Widening Participation in HE and has research interests in HE policy.

Acknowledgement

Data used in this article was originally collected by researchers from the Aimhigher Research Network for a National Union of Students Wales/Open University (2014) study of part-time HE ‘It’s About Time (Available at http://www.nusconnect.org.uk/asset/News/6156/Its-About-Time-2014.pdf’).

Disclosure statement

No potential conflict of interest was reported by the authors.

References