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Dear Weihua
Something along the lines you describe was carried out in England. The RCT was called ASSIST and it was led by Rona Campbell at Bristol University. You might want to look at some of the references below and use them to inform the project you have in mind.
with regards

Campbell R, Starkey F, Holliday J, Audrey S, Bloor M, Parry-Langdon N, Hughes R, Moore L. An informal school-based peer-led intervention for smoking prevention in adolescence (ASSIST): a cluster randomized trial. The Lancet. 2008;371:1595-1602

Audrey S, Holliday J, Campbell R. Commitment and compatibility: Teachers’ perspectives on the implementation of an effective school-based, peer-led smoking intervention. Health Education Journal 2008;67(2):74-90 (DOI: 10.1177/0017896908089387)

Audrey, S. Holliday J. Campbell R. It's good to talk: Adolescent perspectives of an informal, peer-led intervention to reduce smoking. Social Science & Medicine 2006:63:320-334.

Audrey S, Holliday J, Parry Langdon N, Campbell R. Meeting the challenges of implementing process evaluation within randomised controlled trials: the example of ASSIST (A Stop Smoking In Schools Trial) Health Educ. Res. 2006 21;3:366-377. doi:10.1093/her/cyl029

Starkey F, Moore L, Campbell R, Sidaway M, Bloor M. and ASSIST (A Stop Smoking in Schools Trial) Rationale, design and conduct of a comprehensive evaluation of a school-based peer-led anti-smoking intervention in the UK: the ASSIST cluster randomised trial [ISRCTN55572965]. BMC Public Health 2005, 5:43. doi:10.1186/1471-2458-5-43.

From: Social Networks Discussion Forum [[log in to unmask]] On Behalf Of Weihua An [[log in to unmask]]
Sent: 29 January 2010 18:07
To: [log in to unmask]
Subject: soliciting ideas on social network experiment

***** To join INSNA, visit ***** Dear all,

I wonder if you could please shed light on how to conduct a project involving social network experiment. Basically, suppose I can conduct the experiment in roughly 60 middle schools and the outcome I am interested in is the prevalence of cigarette smoking among students. What experimental design with social network component will you view or suggest as innovative and important?

I can think of this on two lines. One is to test an important proposition in social network analysis that opinion leaders can accelerate the diffusion of (positive) attitudinal and behavioral changes. There will be three experimental conditions. The control condition is with no intervention. The first treatment condition is randomly picking changing agents. The second treatment condition is picking the opinion leaders as change agents. Then we compare the efficacy of these three conditions. Of course, we can add some twist to the procedure of how to pick opinion leaders, like contrasting opinion leaders chosen using in-degree with those chosen with eigenvector centrality or others, etc. I know there were a lot of studies using variations of this kind of design (Kelly et al. 1991; Latkin 1998; Valente and Davis 1999; Sikkema et al. 2000; Larkey et al. 2002; Stoty et al. 2002; Woff et al. 2004; Valente 2005), but I did not see any studies directly and purely using this design in public health literature. Does this design seem too obvious? I am also concerned that the individual-based interventions of this design may not be effective at all.

The other is to use group intervention. For example, Wing and Jeffery (1999) showed that group treatment was more effective than individual treatment in a weight loss program.

Some studies like Buller et al. (2000) and Valente (2003) combined the above two approaches, using opinion leaders to lead group interventions. I am concerned with interference between groups or cliques as called in Buller et al. (2000).  Also, the combination makes it hard to disentangle which network feature, between opinion leaders and group cohesion, matters in terms of preventing cigarette smoking.

I am also concerned with the unit of analysis. Because the number of schools are small (some may even drop off when they are asked to sign up), I thought about conducting the randomization on classroom level. But the interference between classrooms may become a big problem for inference of the intervention effects.

Whether you happen to work on this area or not, I would really appreciate your comments on my concerns and suggestions on how to make an "innovative" social network experiment given the above constrains, etc. Any perspective will be extremely welcomed. Thanks very much!



Weihua (Edward) An

Ph.D. Candidate in Sociology
Doctoral Fellow in Social Policy
Graduate Associate of IQSS
Harvard University
568 William James Hall
33 Kirkland Street
Cambridge, MA  02138<>
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