How Avela Match Runs Lotteries

When more students apply to a school than there are available seats, Match uses a lottery to determine placement. This article explains how lotteries work in Avela and how they can be configured to reflect your organization's policies.

How the lottery works

Each Avela match requires three inputs: applications, priorities, and capacities. It also generates one input for you: the random lottery number for each applicant.

The lottery will:

• Take in all of the applications you select
• Check those applications for attributes you want to prioritize
• Assign each application a random lottery number to rank applicants of equal priority, and
• Output an ordered list of applications at each school and grade.

Based on the available capacity at each school and grade, the lottery will assign the top applications to receive offers, and the rest to be placed on the waitlist.

Capacities

The first input is the available capacity at each school and grade included in the lottery. This can be entered in Avela well in advance. You can read more about Capacities here.

Applications

The next input is the pool of applications to be included in the lottery. These might be only the applications for a single grade within a school, for all grades in a single school, or for all schools within a district or charter network. When conducting a lottery, you will filter to the pool of applications that you want to include, select them all, and choose the bulk action “Run Match”.

Priority groups

Priority groups define who gets considered for seats first. Every school in a match can have its own priority group configuration, and applicants are sorted into groups based on the tags on their application.

Think of priority groups as tiers. All applicants in the first group are considered before anyone in the second group, and so on.

Priority groups in Avela are extremely flexible and can be configured to meet your organization’s policies. Groups can be set up so that:

• They require multiple tags on the same application (i.e., “And” logic)
• There can be multiple tags that grant the same priority (i.e., “Or” logic)
• They exclude applications that have a certain tag (i.e., “Not” logic)

“And” logic

If a group uses “and” logic, an applicant must have all of the specified tags to land in this group.

Example: A group configured for both Sibling and InDistrict only includes applicants who have both tags. An applicant with only Sibling does not qualify.

“Or” logic

If a group uses “or” logic, an applicant needs any one of the specified tags to qualify.

Example: A group configured for either Sibling or InDistrict includes applicants who have at least one of those tags.

“Not” logic

An applicant must not have the specified tag to qualify.

Example: A group configured for not InDistrict includes every applicant who does not have the InDistrict tag. This is useful for creating a lower-priority group for out-of-district applicants beneath a higher-priority in-district group.

Combining group logic

These logic types can be combined. For example, you could configure a group for applicants who have Sibling and do not have OutOfState. Or you could configure your highest priority group to be applicants with (Sibling and InDistrict) or (Employee Child and InDistrict), if you prioritize them equally.

Lottery Number

Once applicants are sorted into priority groups, they must be further ranked individually within the group: this is where the lottery number comes in. Every applicant in a match receives a lottery number — a randomly assigned value generated at the time the match is run. This number determines an applicant's position within their priority group when seats are awarded.

Lottery numbers are assigned once and persist across match runs. If you run a match multiple times, applicants keep their original numbers. This ensures consistency and prevents applicants from being disadvantaged or advantaged simply because a match was re-run.

Weighted lottery

A weighted lottery gives certain applicants more chances at a favorable lottery number by assigning them additional draws. Each draw is an independently generated lottery number. The best number across all of an applicant's draws is the one used in the match. More draws means better odds — the same idea as giving a student extra lottery tickets.

Example: A school wants to give applicants who qualify for free or reduced lunch a stronger chance. Applicants tagged FRL are configured to receive 3 draws, while all other applicants receive the default of 1. An FRL applicant gets three independently generated lottery numbers and uses the best one.

How this differs from SchoolMint

If your organization is moving from SchoolMint, it's worth knowing that "weighted lottery" means something different in each system.

In Avela, a weighted lottery works through extra lottery draws. Applicants in a weighted group get multiple independently generated lottery numbers and use their best one. This preserves randomness as the underlying mechanism: higher-weighted applicants have statistically better odds, but placement is not guaranteed by weight alone. An applicant with fewer draws who receives a very favorable lottery number can still rank ahead of a more heavily weighted applicant who drew less favorable numbers.

In SchoolMint Enroll, a weighted lottery assigns a fixed numerical weight to each priority group (for example, 5, 3, or 1). Students in a higher-weight group are always placed above those in a lower-weight group — randomness only applies among applicants within the same weight value. Avela’s weighted lottery is equivalent to Schoolmint’s Enroll’s Extra Entry Sub Lottery.

In legacy SchoolMint Enrollment, weighted lotteries are the same as Avela weighted lotteries.

Both approaches increase the likelihood of placement for priority groups. The difference is that Avela's model keeps the lottery probabilistic, while SchoolMint's weighted lottery removes randomness between weight tiers entirely and can be achieved with Avela’s Priority Groups.

If you have any questions about converting your lotteries, work with your Avela Client Services Rep.
 

How the lottery handles siblings

In addition to the configurations listed above, Avela Match can employ special rules for how to handle siblings that are included in the same lottery. These might differ if the siblings are applying in different grades (i.e., “dynamic siblings”), or if they are applying to the same grade (i.e., twins or “tuplets”).

Dynamic siblings

When siblings apply to the same school in the same enrollment period at different grade levels, they can be automatically linked during the match.

When siblings are detected, a temporary tag is applied to the eligible sibling(s) during the match. This tag can be placed in any priority group, so siblings automatically sort into the appropriate tier without requiring staff to tag them manually.

Example: Two siblings apply to the same school — one for Grade 3, one for Grade 5. The school's configuration places anyone with the dynamic sibling tag in the highest priority group. During the match, the student in Grade 3 is selected to receive an offer. The sibling in Grade 5 is then automatically granted the dynamic sibling tag, and is placed into the top priority group for Grade 5.

A few things to keep in mind:

• Dynamic sibling tags are removed after each match completes. Because different match runs can produce different results, the tag is recalculated fresh each time.
• Applicants who land on the waitlist via the sibling priority will need to be manually tagged or enabled via an autotagging rule if you want to preserve their dynamic sibling priority on the waitlist.
• The lottery, and therefore sibling detection, runs from the lowest grade to the highest. This means that a student applying for Grade 1 will not receive any priority if their sibling is made an offer at Grade 4; the placements for Grade 1 will have already occurred.

Dynamic sibling priority is optional and is configured at the same time as other priorities. Schools wishing to grant dynamic sibling priority will need to include it at the desired place within their priority groups.

Tuplets

A tuplet is a set of siblings applying to the same school and the same grade who share at least one parent or guardian (twins, triplets, etc.). Avela detects tuplets automatically based on guardian relationships.

When a tuplet is detected, the group is given sequential lottery numbers clustered around the best number among them, keeping the siblings as close together in ranking as possible.

Example: Three siblings (a set of triplets) all apply for Kindergarten at the same school. Their original lottery numbers are 10, 22, and 5. Because they are a tuplet, the best number (5) is kept, and the other two are assigned 5.01 and 5.02. All three siblings rank near each other rather than being scattered across the list.

Tuplet handling is optional and is configured per match. When enabled, the group clusters together in the ranking. When disabled, each sibling in the tuplet is treated as an independent applicant.