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Relatively
Surprisingly
Remarkably
Comparatively
few
studies have
analysed …
assessed …
examined …
measured …
investigated …
little
research has
While
Whilst
Although
some research has been
carried out on X,
no single study exists which ...
no studies have been found which ...
no controlled studies have been reported.
there is very little scientific understanding of ...
only two studies have attempted to investigate ...
there have been few empirical investigations into ...
the mechanism by which ... has not been established.
little if any empirical work has been done to investigate …
several studies have shown
that …,
Highlighting inadequacies or weaknesses of previous studies (also refer to Being Critical)
Previous studies of X have not dealt with ...
Researchers have not treated X in much detail.
Such expositions are unsatisfactory because they ...
Such approaches, however, have failed to address …
Most studies in the field of X have only focused on ...
Previous published studies are limited to local surveys.
Half of the studies evaluated failed to specify whether ...
The research to date has tended to focus on X rather than Y.
Previously published studies on the effect of X are not consistent.
Smith’s analysis does not take account of ..., nor does she examine ...
The existing accounts fail to resolve the contradiction between X and Y.
Most studies of X have only been carried out in a small number of areas.
However, much of the research up to now has been descriptive in nature ...
The generalisability of much published research on this issue is problematic.
Research on the subject has been mostly restricted to limited comparisons of ...
However, few writers have been able to draw on any systematic research into ...
Short-term studies such as these do not necessarily show subtle changes over time …
Although extensive research has been carried out on X, no single study exists which ...
However, these results were based upon data from over 30 years ago and it is unclear if ...
The experimental data are rather controversial, and there is no general agreement about ...
However, all the previous X research was cross-sectional in design. Therefore, it is unclear if …
Although there are many reports in the literature on the outcome of X, most are restricted to ...
Some evidence suggests that ..., although further work using X is required to confirm this finding.