PennNames Generate Algorithm

Following is a discussion of how PennNames are generated when using the PennNames Generate command.

• Terminology
• Overview
• Sources of the Names
• Basic Generation of the Names
• Extended Generation of the Names
• Name-material weighting
• Name Validation and Results

In this discussion of the Generate command algorithm the following terminology will be used:

Term		Description		Example
PennCommunity-Fullname		This is the full name of the user as stored in PennCommunity, in the format, LAST_NAME FIRST_NAME MIDDLE_NAME.		Smith, John H
User-Supplied-Name		This is any name information supplied as an optional argument to the Generate command in the <FULLNAME> variable. This may be the full name of the user, or it may be something completely arbitrary.		Jack Smith
Seed		This is a string which the user prefers for his/her username. This information is supplied as an optional argument to the Generate command in the <SEED> variable, the string that is prepended by a colon when issuing the Generate command. Please note that the colon is not factored into the algorithm. It has the highest weight.		bozo
Name-Material		This is the combination of data from PennCommunity_Supplied_Fullname plus the Seed or the User-Supplied-Name plus the Seed and is used to generate a list of potential usernames. Any punctuation is stripped out so that "John H. Smith, Jr." becomes "John H Smith Jr".		bozo Jack Smith

A good-looking username consists of a large portion of one part of a user's name, either followed by or preceeded by a small portion of another part of his/her name.

For example, let's consider the user whose PennCommunity FIRST_NAME is "Ziggy", whose PennCommunity LAST_NAME is "Bozo", and who doesn't have a PennCommunity MIDDLE_NAME. It is likely that Ziggy would prefer the following names:

• bozo
• ziggy
• zbozo
• bozoz
• ziggyb

In practice, some of those names will be unavailable since they might be assigned to some other person on campus or reserved by another sponsor. Likely secondary choices for Ziggy might be:

• bozo2
• ziggy2
• zbozo2
• bozoz2
• ziggyb2

Of course there are a lot of variables. There's no guarantee that we'll have a middle initial. Even if we do, it's possible that the user prefers to go by their second name, the user could have two middle names, the PennCommunity information might be inaccurate, and so on. So a wide variety of names should be generated to try and cover as many of these possibilities as is practical.

Previous versions of the PennNames name generation algorithm were considered to have too high a weight on the middle name since the first name, last name and middle name had been weighted equally. The current version of the algorithm tries to deduce which name is the middle name, and give it a lower priority than other seed material.

The implemented algorithm has three sources of potential Name-Material. They are :

• the PennCommunity-Fullname
• an optional User-Supplied-Name
• an optional Seed

The basic premise is that all seed material falls in to one of three categories: high, medium or low weight. The PennCommunity-Fullname is examined, and middle names are given a low weight. The optional Seed, if provided, is given a high weight. Titles and suffixes (e.g. Mrs., Jr., Sr.) are discarded. Everything else is given a medium weight.

The namestream is a series of "lazy enumeration" functions which generate more results on demand. These functions are stacked on top of each other such that the generate results from the high priority material first; then the high and medium priority material; then the high, medium and low material in conjunction. The lazy enumeration will only do as much work as it needs to in order to return the target number of suggested names.

There is also a time limit placed on the namestream generator. If the time expires then the result list will be cut short. This prevents a runaway server or malfunctioning service from denying access to the PennNames service.

The mixing of names is done in stages:

• Each piece of material by itself
• Mixed pairs of material
• Mixed triplets of material

No more than three pieces of material are ever considered for a generated name.

In our simplest example where the PennCommunity FIRST_NAME is "Ziggy", the PennCommunity LAST_NAME is "Bozo", the PennComunity MIDDLE_NAME is blank, and no User-Supplied-Name or Seed has been supplied, the Name-Material will be "Bozo Ziggy" (note: last name first) and we will generate these names:

bozo ziggy bozoz ziggyb bziggy zbozo bozozi ziggybo bz

zb boziggy zibozo bozozig ziggyboz bzi zbo boz zib

bozziggy zigbozo bozozigg zboz bzig zibo bozi zigb bozz

ziggbozo bzigg ziboz bozig zigbo bozzi ziggb bozigg zigboz

bozzig ziggbo bozzigg ziggboz bo zi zig zigg

Those are the only 44 possible names generated from the given source material.

As a final resort, the lazy enumerator will begin to postpend numbers if the material is completely used up. The names generated will look like this:

You'll notice that this starts with the first results from the initial generate, above. The order in which the seeds themselves are consulted is guaranteed, but the point at which they're used is not. In this case there are two uses of 'boz o', then one of 'ziggy'. This may not be true of all cases. In general, this number-postpending mechanism is considered a mechanism of last resort so it is hoped that one need not rely on the efficacy of the extension; if you get here, nothing that you want is avaiable anyway.

As mentioned above, not every piece of Name-Material carries the same weight. For example, if we add a middle name ("Quartermaine") for Ziggy, we then have the Name-Material "Bozo Ziggy Quartermaine" and generate these names:

bozo ziggy bozoz ziggyb bziggy zbozo bozozi ziggybo bz zb boziggy zibozo bozozig ziggyboz bzi zbo boz zib bozziggy zigbozo bozozigg zboz bzig zibo bozi zigb bozz ziggbozo bzigg ziboz bozig zigbo bozzi ziggb bozigg zigboz bozzig ziggbo bozzigg ziggboz bozoq ziggyq bo zi qu qbozo qziggy zig qua bozoqu ziggyqu zigg quar bq zq qb qz bozozq bozoqz ziggybq ziggyqb quart qubozo quziggy quarte bozoqua ziggyqua quarter bqu zqu qbo qzi bozozqu bozoqzi ziggybqu ziggyqbo quarterm boq ziq qub quz bziggyq zbozoq qbozoz qziggyb quabozo quaziggy bozoquar qboz bqua zqua

qubo qzig bozozqua bozoqzig qziggybo boqu ziqu quab quzi bziggyqu zbozoqu ziggyqub qbozozi bozq zigq quarbozo quaz bozoziq bozoquz ziggyboq zqbozo qzbozo quboz bqziggy qbziggy bquar quabo qzigg boqua zquar quarb quzig zqb qbozozig qzb bozqu ziqua quazi bozoquzi zbozoqua zigqu quaboz quarz bozoziqu bqz qbz bquart ziggq quarbo bzq zbq zqbo qzbo boquar quartb quzigg quziggyb bozqua zquart quazig ziquar quarboz quarzi bqzi zqboz qbzi qzboz bquarte zigqua quartbo quartz qubozoz boquart ziggqu quarteb bozquar quazigg bzqu zbqu zqubozo qzibozo zquarte quartboz quarzig boziggyq bqzig zibozoq qbzig bquarter ziquart quartebo

quartzi qubozozi boquarte zigquar quarterb quartez bozoquaz zqub qzib bozquart ziggqua bquziggy ziqbozo qboziggy quzbozo quarzigg bqzigg qbzigg zquarter quartzig zqubo qzibo ziquarte quartezi bzqua zbqua ziqb quzb zigquart quarterz bquz zibozoqu ziggquar bozozigq boqziggy zquboz qubziggy qziboz ziqbo quzbo bquzi qbozi boqz ziqboz qubz quzboz bzquar zbquar bquzig zquabozo qbozig qzigbozo boqzi qubzi bziq zboq quabozoz zquab qzigb bquzigg ziqubozo qbozigg quzibozo boqzig qubzig zquabo qzigbo ziqub qbozz quzib bzquart zbquart zigqbozo quazbozo boqzigg zquaboz qubzigg qzigboz ziqubo quzibo bziqu zboqu zigqb qbozzi quazb bquaz zibq ziquboz quziboz zigqbo quazbo

qbozzig bquazi qubozi boquz zigqboz quabz quazboz bzquarte zbquarte qbozzigg qziggb bquazig qubozig bziqua boquzi zboqua quabzi bozqz zibqu qziggbo zigbozoq zquarb quzigb bquazigg qubozigg boquzig quabzig qziggboz bozqzi zquarbo quzigbo ziquab qubozz quazib boquzigg zquarboz quabzigg quzigboz bozqzig ziquabo quazibo zigqub qubozzi quarzb bziquar bquarz zboquar zibqua ziquaboz quaziboz bozqzigg zigqubo quarzbo zbozq ziggqb qubozzig bquarzi quabozi boquaz zigquboz quarbz quarzboz ziggqbo quziggb bquarzig quabozig boquazi ziggqboz quarbzi bozquz quziggbo bziquart zboquart zquartb quazigb zibquar boquazig quarbzig bozquzi zbozqu zquartbo quazigbo bzigq ziboq ziquarb quabozz quarzib bozquzig ziquarbo quarzibo zigquab

quabozzi quartzb bquartz zigquabo quartzbo zibquart ziggqub bquartzi quarbozi boquarz zbozqua quartbz bzigqu ziboqu ziggqubo boziq zigbq quaziggb boquarzi quartbzi bozquaz zquarteb quarzigb bozquazi ziquartb quarbozz quartzib zbozquar bzigqua ziboqua boziqu zigbqu bozzq zigquarb quartezb bquartez ziggquab boquartz quartebz bzigquar ziboquar boziqua zigbqua bozzqu bozquarz bziggq zibozq boziquar zigbquar bozzqua bziggqu zibozqu bozigq zigboq bozzquar bziggqua zibozqua bozigqu zigboqu bozziq ziggbq bozigqua zigboqua bozziqu ziggbqu boziggq zigbozq bozquarz bziggq zibozq boziquar zigbquar bozzqua bziggqu zibozqu bozigq zigboq bozzquar bziggqua zibozqua bozigqu zigboqu bozziq ziggbq bozigqua zigboqua bozziqu ziggbqu boziggq zigbozq

Note that the middle name is not consulted until the other Name-Material is nearly exhausted (at position 41). This means that typical generate request which is usually for 15-25 names will not generally use the middle name at all.

Since this algorithm uses a lazy iterator, the results are vetted immediately upon generation. Names which are not available are immediately discarded. This results in a significantly faster algorithm than the previous iteration; generating 1000 names takes approximately 8 seconds with the new algorithm, whereas we saw generates of 100 take over 30 seconds with the previous algorithm. This should help avoid server deadlock under high load.

The list of results is returned to the PennNames client, up to but no more than the maximum number of names that were requested. This iterator should never run out of material (there are an endless supply of numbers), and so should always return the exact number of requested names. Even so, do not assume that asking for 25 names will return 25 names. It will return up to 25 names. Some cases wind up returning only one name, or only the set of names that are already held for a given PennID. It is only guaranteed that the server will not return more results than what you requested.