Current understanding

to re-examine …

to revisit …

… the long-standing issue of …

… the long-standing question

to take up and build on earlier research

The issue, problem, cause etc. of …

… merits further study

… deserves further consideration

… is worth examining more closely

… is worth exploring further

… has not yet been addressed fully

… is neglected in current theory

… is not yet clearly understood

… is not yet completely understood

… is not well understood

… is poorly understood

successive attempts have failed to solve

this approach gives a better basis for …

The problem is a complex one.

… presents a difficult set of problems

… poses a number of problems:

… poses particular problems in cases where …

the prevailing view is that …

… is widely perceived as …

the question has been raised whether …

Present understanding of … is limited.

the field of … is still relatively undeveloped

there is as yet or at present no consensus on …

As yet, no one explanation has gained acceptance.

there is at present little agreement on the causes of etc. …

there is at present no general agreement on the causes of etc. …

there is still considerable disagreement on the causes of etc. …

the mechanism by which … is unknown or not well understood

the controversial question of …

much of our knowledge of … comes from …

the task of … is complicated further by …

The impact of … on … is not easy to determine

The effect of … on … has not been examined in detail.

its effects on … have not previously been studied in detail

Importance of the study

The study is important for a number of reasons:

The study is of relevance because …

It is important to …

the importance of …

an important aspect of …

… is an important or urgent subject for study

… is needed

… is necessary

… warrants further investigation

… warrants closer scrutiny or examination

The problem merits further investigation.

… is worth examining for its own sake

… to shed light on a number of issues or problem areas in current theory

Resolution of this problem would …

the prospect of a breakthrough in …

Other authors have also called for …

This study, thesis, paper etc.

… may show or reveal …

… may stimulate the debate on …

… may provide evidence of or for …

… may contribute to our understanding of …

… may contribute towards a better understanding of …

… may offer an alternative view or explanation of …

… may enable a better explanation of …