Using Multiple Lists
Some tracks have special requirements that can only be satisfied by submitting multiple Rank Order Lists for a single track. Using Multiple Lists, it is possible within the matching algorithm to attempt to recruit a particular "mix" or distribution of applicants based on specific applicant characteristics.
Review Common Scenarios for Using Multiple Lists
The examples provided below are representative only. Contact NMS to discuss your situation.
- A track with multiple positions would like to rank several applicants from a specific group (e.g., from one school or one state) but does not want to give special priority to the group, and would like to limit the number of applicants matched from the group. The track can use the multiple list option to offer their positions in a manner consistent with their overall ranking preferences while ensuring the track does not match with more than a specified maximum number of applicants from the group.
- A track would like to improve diversity by ensuring that at least one of its matched applicants is from a specific group (gender, ethnicity, language, location of residence, school, etc.), but the track does not want to have unfilled positions if the track is unable to match with an acceptable applicant from that group. The track can use the multiple list option to give priority to filling at least one position from the group, while allowing for matching with more than one applicant from that group if that is consistent with their overall preferences. In addition, the track can use the reversion option to ensure that if all ranked applicants from that group match to other programs, the track can still fill all its positions with other acceptable applicants (even though that may not meet their diversity preferences).
Programs offering more than one track in the Match can choose to submit multiple lists for some or all of their tracks, if desired. For example, a program offering a scholarship track and a track with no funding could choose to submit two lists for the scholarship track and only one list for the track with no funding, if that was necessary to satisfy their requirements.
When a track sets up Multiple Lists, each List is assigned a unique list identifier (e.g., A and B) to distinguish each List within the NMS Match System. In cases where the same applicant is ranked on more than one List and can match on more than one List, the list identifier also imputes an alphabetic priority to the Lists, and the applicant will match on the List with the higher priority (e.g., List A ahead of List B).
Applicants being considered for a track that chooses to submit Multiple Lists only need to rank the single Match Code Number originally assigned to the track. Applicants do not need to know that the track is submitting Multiple Lists, or on which specific List(s) they will be ranked.
When the Match results are distributed to you, the applicants matched from the various Lists will be combined together, so that you will receive a single integrated list of applicants matched to the track.
Special Cases within Multiple Lists
Ranking the Same Applicant on More than One List
It is likely that, in most cases, an applicant will appear on only one of the Lists submitted for the track. However, it is permissible to rank a single individual on more than one List for a track, and to assign a different rank number to the applicant on each List if desired.
If you rank the same applicant on Multiple Lists for the same track, a situation can arise where that applicant can match to the track on more than one List. The matching algorithm addresses this situation by assigning a priority to each List that determines on which List the applicant will match.
Each List is automatically assigned an alphabetical priority (e.g., A, B, C,). An applicant who can match on more than one List will be matched on the List with the higher alphabetic priority. For example, if an applicant can match on both List A and List B, then the applicant will match on List A, and the position on List B will be filled by another applicant from List B if possible.
You must consider this alphabetic priority when setting up your Multiple Lists.
Note: The alphabetic priority for each List is relevant only when the same applicant can match on more than one List, and does not affect the matching process in any other way.
Revert Unfilled Positions Between Lists
Finalize your Multiple List setup before adding any reversion.
For each Multiple List you set up, you should consider whether or not you wish to revert any unfilled positions from that List to another one of the Multiple Lists for the same track, or to a Rank Order List for a different track at your program.
Reverting unfilled positions from one List to another may reduce the likelihood that the track will be left with any unfilled positions after the Match.
Note: One of the usual restrictions on reversions is that you cannot specify a reversion of unfilled positions from List A to List B, and another reversion from List B to List A (i.e., a circular reversion). However, there is a technique that can be used to circumvent this restriction for the reversion of positions between Multiple Lists for the same track. Refer to the example on Preference for Composition of Applicants From Two Different Groups below.
Multiple List User Guide
Consult the Multiple List User Guide for detailed instructions for submitting Multiple Lists using the NMS Match System.Multiple List User Guide
Multiple List Examples
The examples provided below are representative only. If you are uncertain as to whether your requirements can be accommodated using Multiple Lists, please contact NMS as soon as possible.
Preference for At Least One Applicant With a Certain Characteristic
Suppose a track has 3 positions and 8 applicants, some of whom are bilingual. The overall preferences for these applicants (ignoring each applicant's bilingual capabilities) are:
Rank Applicant Bilingual? 1 George no 2 Mary yes 3 Greg no 4 Sally yes 5 Ruth no 6 Frank no 7 Jane no 8 Bob yes
Now suppose that the track’s requirements for matching with these applicants are as follows:
- It is important that the track fill at least one position with a bilingual applicant. More than one bilingual applicant would be acceptable, but a strong preference must be given to filling at least one position with a bilingual applicant.
- The track will only accept a match with Bob in order to match with a bilingual applicant. If the track matches with one of the other preferred bilingual applicants, the track would rather have an unfilled position than match with Bob.
- If the track does not match with any of the bilingual applicants, it would prefer to fill all 3 positions with applicants who are not bilingual, rather than have an unfilled position after the Match.
This track can satisfy its requirements by submitting two Lists and a reversion, as follows:
List A (Bilingual) - 1 position Rank Applicant 1 Mary 2 Sally 3 Bob List B - 2 positions Rank Applicant 1 George 2 Greg 3 Sally 4 Ruth 5 Frank 6 Jane
Reversion: If the position is not filled on List A, revert the unfilled position to List B.
List A, with 1 position, consists of all the bilingual applicants and only the bilingual applicants in preference order. By separating these applicants on List A, which is given priority in the Match, the track will attempt to fill at least one position with a bilingual applicant.
List B, with the other 2 positions, consists of all applicants in preference order except for Mary and Bob. These two applicants have been omitted from List B for different reasons:
- Mary could have been ranked on List B as well, between George and Greg, but there is no point in doing so. Since Mary is the first choice on List A, and List A is given priority in the Match over List B, if Mary matches to this track, she will do so on List A.
- Bob is desirable only as a bilingual candidate, and will be matched only on List A if necessary to fill the bilingual position. If he is not matched on List A, the track does not want to match with him on List B.
On the other hand, Sally is included on both Lists. If the track matches with Mary on List A, the track would still be happy to match with Sally as a second bilingual applicant, provided the track does not fill the positions with more preferred applicants. Hence, Sally is also included in the appropriate position on List B.
If the position on List A remains unfilled, the track has specified that the position should revert to List B. If the track is unable to match with a bilingual applicant, it will attempt to fill all three positions with non-bilingual applicants before it ends up with an unfilled position after the Match.
Preference for Composition of Applicants From Two Different Groups
Suppose a track has 4 positions and 9 applicants. The track is involved in some research projects and would like to fill 2 positions with applicants who have indicated a desire to devote a portion of their time to these research projects, and 2 positions with applicant who are not interested in spending time on the research projects.
The track can classify its applicant pool into 2 distinct groups based on the applicants’ interests in participating in the research projects. For example, the applicant pool might be grouped as follows:
Interested in Doing Research Not Interested in Doing Research Lynn David Sandra Mark Rahim Rhonda Ellen Boris Bella
While the track would prefer to match with 2 applicants from each group, it is prepared to forego this distinction entirely in order to ensure that it fills all its positions. In other words, it is prepared to fill up to 4 positions with applicants from either group, if necessary, to avoid having any unfilled positions.
Because the track has no idea which List might fill and which List might be left with unfilled positions, it wants to set up a reversion from List A to List B and then add a second reversion from List B to List A. However, this type of "circular" reversion is not allowed.
One way to address this requirement is to set up Multiple Lists and a reversion as follows:
List A - 2 positions Rank Applicant 1 Lynn 2 Sandra 3 Rahim 4 Ellen List B - 2 positions Rank Applicant 1 David 2 Mark 3 Rhonda 4 Boris 5 Bella 6 Rahim 7 Ellen
Reversion: Revert all unfilled positions from List A to List B.
List A consists of all those applicants with an interest in doing research. An attempt will first be made to fill 2 positions from this group of applicants. However, if any unfilled positions remain on this List, the positions are reverted to List B in order to attempt to fill the positions with additional applicants who are not interested in research.
The first 5 ranks on List B are all those applicants who are not interested in doing research. An attempt will first be made to fill 2 positions from this group of applicants. Furthermore, for example, if only one applicant is matched on List A and the first 2 choices are matched on List B, then the unfilled position will be reverted from List A to List B, and an attempt will be made to fill the position with other applicants from List B.
But what if List A fills with the first 2 choices, and only 1 applicant is matched on List B from the top 5 choices on that List (the applicants not interested in research)?
Instead of reverting the unfilled position from List B to List A (which is not allowed), the additional applicants from List A have been added to the end of List B, so that an attempt will be made to fill the position with another applicant who is interested in research. Note: There is no point in adding the first 2 applicants ranked on List A to List B - if Lynn or Sandra match to this track they will do so on List A, since List A is given priority and has 2 positions.
However, adding Rahim and Ellen to the end of List B provides the opportunity to match with additional applicants interested in research if both Lynn and Sandra match on List A and one or both of the positions on List B remain unfilled.
As a minor variation on this approach, suppose the preferences for Rahim and Ellen are different depending on whether they are being matched from List A or List B. For example, Rahim may have more research skills than Ellen and therefore is more preferred on List A if the research positions are not filled with other more preferred applicants.
The only reason these applicants might match on List B is if the research positions are filled on List A and the positions on List B are not filled by applicants who are not interested in research. In this case, the track might actually prefer Ellen to Rahim, since the track has already matched with other strong research applicants. As a result, the track might choose to reverse the rankings of these applicants on List B by ranking Ellen 6th and Rahim 7th, therefore giving Ellen preference over Rahim on List B.
This technique for circumventing circular reversions can only be used for Multiple Lists submitted for a single track. It cannot be used for reversions between different tracks, since there is no guarantee the applicants will rank both Match Code Numbers.