Transactions on Graph Data and Knowledge (TGDK) welcomes proposals for Special Issues (SIs) devoted to a specific topic that is within its scope. Successful proposals will focus on research or application areas of emerging significance or for which innovative and novel work is being done.

Proposals

An SI proposal should include the following information:

• Two or more people who will serve as the SI Guest Editors and work with the TGDK Editors-in-Chief and/or an Associate Editor to produce the issue. A short biography should be submitted for each. Please select one Guest Editor to be the lead point of contact.
• A concise description of the SI topic along with a justification of why an SI is appropriate at this time.
• A description of the research communities that the SI will draw from or be of interest to.
• Any papers or authors that the SI Guest Editors intend to invite.
• Any constraints or preferences for publication date.

Proposals should be sent to the Editors-in-Chief via email to contact@tgdk.org.

Timeline

The actual publication date and number of pages for accepted SI proposals will be decided by the EiCs in consultation with the SI Guest Editors and is subject to the constraints imposed by the publisher. A typical schedule will allow for three to six months before submissions are due, two months for the initial reviews, one month for subsequent revisions, and one month for a final version. A well expedited SI can complete in eight months.

Submissions

All SIs must have an open call for submissions to which members of the research community can respond by submitting papers. The SI Guest Editors are free, of course, to invite submissions. The SI Guest Editors will be expected to advertise the call in appropriate venues.

To avoid the appearance of a conflict of interest, the SI Guest Editors are expected not to submit papers to the SI or be a co-author on papers submitted. They are free, of course, to submit papers on the SI topic as regular papers to the journal.

Review Process

All papers, whether invited or submitted to a Special Issue, will undergo the same thorough review process used for regular papers submitted to the journal. This normally involves seeking reviews from three qualified reviewers. The SI Guest Editors will be responsible for recruiting potential reviewers prior to the submission due date and ensuring that their reviews are done in a timely manner and are of high quality.

The submission and review process must be carried out using the standard journal platform as indicated by the EiCs. This includes accepting initial submissions, recruiting and assigning reviewers, entering reviews, issuing decisions, submitting revised version and providing the final version of accepted papers.

When submissions are received, the SI Guest Editors should examine the papers to ensure that they are within scope, of appropriate length, and meet minimum standards for organization and readability. Papers that fail any of these criteria should be rejected without review by the SI Guest Editors. Papers that meet the criteria should be assigned to three reviewers, who should be given four to eight weeks to complete their reviews. After all of the reviews for a paper are completed, the SI Guest Editors should decide on one of the following results:

• Reject: The paper will not be considered further.
• Major revision: The paper requires significant changes before it can be accepted. These might include additional discussion, sections, analyses of data or even further experiments. If and when a revision is submitted it should be sent back to the original reviewers who will enter new reviews, typically within one month. When all of the reviews are in, the SI editors should then decide on one of reject, minor revision or accept, i.e., a second major revision decision should not be made.
• Minor revision: Relatively small changes are required before the paper is accepted. When a revised version is received, the SI editors will review the paper to ensure that the changes were made rather than sending it back to the original reviewers.
• Accept: The paper is accepted as is and requires no additional changes.

Final decisions of accepted papers must be approved by an EiC.

Instructions for SI Guest Editors

1. It is worthwhile to do a first check with respect to the quality of the papers submitted. It is our experience that 25% or more of the paper submissions are outside the scope of SI or are of such low quality that it is not worthwhile to hand them over to reviewers. In such cases we suggest that you skim the paper and give two or three concrete reasons why the paper will not be acceptable by any means in its current form. This is sufficient to reject such papers. If the paper is outside the SI scope but looks to be of reasonable quality and within the scope of the journal, you can suggest that the authors consider re-submitting it as a regular paper.
2. For all other papers we expect three detailed reviews. If you have a particularly expert reviewer in mind who might be overburdened with other tasks you might consider adding a fourth review to increase the chances of getting three reviews in time.
3. For SI's we expect the following cycle:
   1. Original submission by authors: Papers are classified by SI Guest Editors as reject (frequent), major revision (frequent), minor revision (occasional), or accept (rare).
   2. Major changes by authors: The paper must be re-reviewed by the reviewers to see whether it is now acceptable. Sometimes reviewers have the opinion that papers can only get better and hence their judgement can only go up (e.g. from major to minor revision). This is of course wrong, if authors fail to meet expectations by reviewers a paper may have to be rejected after a major revision.
   3. Minor revision: These changes should usually be checkable by SI Guest Editors. If a paper is basically accepted and trivial changes are to be applied (e.g. typo correction), then a paper must not be classified as "accept" but rather as minor revision.
   4. Accept: From here on the paper goes into production for publication. Authors no longer have the possibility to change the paper, they can only correct mistakes inadvertently introduced via proofs supplied in the paper production process.
   EiCs usually accept SI Guest Editor decisions, but we keep an eye on all decisions with the following objectives:
   1. To have a process and decisions that are as transparent to authors as possible
   2. To not have decisions that are in stark contrast with reviewers' opinion – unless explained otherwise.
4. Submission and acceptance rates: We do not enforce any kind of acceptance rate on SIs but we enforce high quality. The acceptance rate may depend on the maturity of the sub-community, the perceived breadth of the topic, and whether the call is likely to attract off-topic papers.
5. We try to publish SI papers in a shorter time span. It can happen that a paper is very worthwhile, but needs a longer time for changes. In this case, rather than reject it, there is the option to redirect it to a normal issue of the journal under the rationale that we do not want to turn away good papers.
6. If any question remains unanswered please to not hesitate to get in touch with us at: contact@tgdk.org.