Davis study still lacks self-selection control group (and the sample is still small)

[Ludo Waltman]

There is an essential difference between what Stevan Harnad says and  
what I am saying. Stevan states that the results of Phil Davis can be  
interpreted as "simply the failure to detect any citation advantage at  
all". He also states that "this failure to replicate is almost  
certainly due to the small sample size as well as the short  
time-span". We seem to agree that no OA citation advantage can be  
detected in Phil's data. What we do not agree about is whether or not  
this is likely to be caused by a small sample size. As indicated in my  
previous post, I consider this to be unlikely. Phil's results show not  
only that there is no OA citation advantage in his sample, but also  
that an OA citation advantage of reasonable size is unlikely to exist  
in the underlying population.

Ludo Waltman


Quoting Stevan Harnad <amsciforum at GMAIL.COM>:

> Adminstrative info for SIGMETRICS (for example unsubscribe):
> http://web.utk.edu/~gwhitney/sigmetrics.html
>
> On Wed, Nov 24, 2010 at 11:52 PM, Ludo Waltman <ludo at ludowaltman.nl> wrote:
>
> LW:
>
> Phil Davis has published interesting results on the question whether open
>> access leads to a citation advantage. In my view, Stevan Harnad's criticism
>> of Phil misses the point...
>
> In my view, Phil has convincingly shown that, at least for the journals and
>> the time intervals he studied, there is no meaningful OA citation advantage.
>
>
> I don't understand Ludo Waltman's point, since this is exactly what I said:
>
> SH:
>
> Phil Davis's dissertation results are welcome and interesting, and include
>> some good theoretical insights, but insofar as the OA Citation Advantage is
>> concerned, the empirical findings turn out to be just a failure to replicate
>> the OA Citation Advantage in that particular sample and time-span... it is
>> most definitely not a demonstration that the OA Advantage is an artifact of
>> self-selection, since there is no control group demonstrating the presence
>> of the citation advantage with self-selected OA and the absence of the
>> citation advantage with randomized OA across the same sample and time-span:
>> There is simply the failure to detect any citation advantage at all.
>
>
> Stevan Harnad
>