Today I hope to cover some of the technical considerations required in implementing command chaining in Ubiquity, and I will follow up soon with a blog post on the linguistic considerations required as well.

Technical considerations: hooking the pipes together

I’d first like to lay out some technical challenges and questions. These can be broken into two different categories: (1) how the parse and display of suggestions is affected and (2) how the execution is affected.

Matching inputs and outputs

We’ll first consider how command chaining may affect the parsing. Ubiquity commands each specify the types of argument inputs that it expects using different noun types, such as noun_arb_text which accepts anything, noun_type_number which accepts numbers, or noun_type_language, which takes the name of a language. For example, the translate verb takes maximally three arguments: a noun_arb_text object, a noun_type_language goal (the language to translate into), and a noun_type_language source (the source language). In implementing command chaining, it will be necessary to identify the appropriate noun types for the output of a command.

The first question we must address here is “what is the chaining output of a command”? Is it the preview text? Some text output from the execution?

Big fish eat da lil fish by joemud, CC-SA-NC

To put this question into perspective, we note that Ubiquity commands can be broadly classified into two types: lookup and action execution. Here’s a classification which I believe to be exhaustive:²

In light of this classification I believe we can say that lookup commands are much more likely to be the first verb in a command chain—conversely, chains such as email hello to Blair and then do ... or twitter hello and then ... are quite unlikely. What is much more likely is for the first verb to be a lookup function.

Thus in the same way that not all commands have a useful execution³ perhaps only lookup commands will have a chainable output: the results of the lookup. Even with this restriction, we will most likely need to implement a new “chainable output” method or getter in these commands. This means that commands will need to opt-in to become chainable, but I believe this is a necessary evil.

The second question we must address is “when do we establish the noun type of a command’s chainable output?” One unsung but crucial feature of the way Ubiquity works now is that suggestions’ previews are not computed until that suggestion is selected (except for the first suggestion, which in most skins gets previewed immediately). Should we wait for all of the first verbs’ chainable output to be computed and then run them through the noun type detection system? Or should verbs with chainable output also a priori specify what noun types their output will be?

Both of these approaches have their problems. If we compute the chainable output of the first verb, run a noun type detection on it and then suggest the full combination if it matches what the second verb was expecting, this will have clear performance implications, not to mention that it could greatly complicate our parsing algorithm. While the latter approach doesn’t have these performance implications, it does mean that it will have to list (by name or reference) the noun types that will match its output, meaning that if a command author is unaware of someone else’s noun type, that chain will be impossible, even if the chainable output itself does indeed match that noun type. The a posteriori approach would never have this issue. What other benefits or problems do you forsee with either of these approaches? Is there another approach which avoids these pitfalls?

(A)synchronous composability

Once we have the noun types, parsing, and suggestions down, all that remains is to compute the previews and implement the composite execution. Since the Ubiquity command manager already wraps the preview and execute functions in a wrapper to facilitate localization, among other uses, it would be easy to make the command manager compose asynchronous processes pseudo-synchronously. No major changes should be necessary to do the previews and executions, though, again, there will be a performance cost.

Conclusion

There are a number of technical questions which must be answered, mostly in the parsing/suggesting stage. The key questions to answer are:

1. What is the chaining output of a command?
2. When do we establish the noun type of a command’s chainable output?

I’ll make another post soon on the linguistic considerations necessary in making command chaining happen in a natural fashion.

Related posts:

1. Command Chaining with Oni?
2. Ubiquity Commands by The Numbers
3. Ubiquity Parser: The Next Generation Demo

Related posts brought to you by Yet Another Related Posts Plugin.

It’s time for one more installment of Nountype Quirks, where I review and tweak Ubiquity’s built-in nountypes. For an introduction to this effort, please read Judging Noun Types and my updates from Day 1 and Day 2.

Today I ended up spending most of the day attempting to implement (but not yet completing) major improvements to the geolocation-related nountypes whose plans I lay out here.

Note: this blog post includes a number of graphs using HTML/CSS formatting. If you are reading this article through a feed reader or planet, I invite you to read it on my site.

noun_type_geolocation

noun_type_geolocation is the nountype used by the weather command for its location argument in input like “weather near Chicago”. The neat feature of noun_type_geolocation is that it has a smart default value which uses Firefox’s geolocation system to give you your current location by default, so I can enter “weather” and get the suggestion “weather near Broomfield, Colorado” (not completely correct, but close enough for the weather). Otherwise, however, noun_type_geolocation does not do too hot… for any input you give it, it’ll just accept it with a score of 0.3, much like noun_arb_text. We could do better.

One issue with this noun_type_geolocation is a conceptual one. Is this nountype supposed to accept only municipalities? Countries? Or should it accept landmarks or addresses as well? Part of the issue is that it’s only used by one built-in command in Ubiquity now, weather. But to be called a general “geolocation” nountype, its output should not be specific to weather’s usage, which is to throw the result at the Weather Underground API.

I propose that we change this to be something like noun_type_geo_town and also make similar nountypes like noun_type_geo_country, noun_type_geo_region, going all the way down to noun_type_address (which already exists—see below). All of the nountypes in this family could use a geocoding API such as Google’s or Yahoo’s. Their data properties could include all of this geocoded geographic data (in English) and also the latitude/longitude coordinate data.

The weather command could then accept noun_type_geo_town but, as some municipalities are not in Weather Underground or, for some countries, it is only as granular as administrative districts, we could just display the results of the geocoding API but then give Weather Underground the geocoded latitude/longitude data.

noun_type_async_address

noun_type_async_address attempts to do exactly what I’ve laid out above for the most granular level: that of geolocations with data all the way down to the street level. This is the nountype which is used for the built-in map command and uses the Yahoo geocoding service to accomplish this. Let’s see what kinds of results it returns:

input	suggestion
mitcho	mitcho	0.5
grenada	grenada	0.9
jono	jono	0.9
mountain view	mountain view	0.9

Let’s lay out some immediate quirks:

1. All scores are either 0.5 or 0.9. In general, if the Yahoo API returns some geocoded interpretation, it gets 0.9, but otherwise it accepts everything with 0.5.
2. The results that came back from the Yahoo service doesn’t add any useful information like the country or administrative region. Even the case stays lowercase.
3. Since when is Jono a location!? I’ll get back to this later.

For starters, the Yahoo! Maps API terms of service dictate that we can’t use its geocoding service if we’re not also displaying Yahoo maps, so I rewrote it using the Google API which also had the advantage of offering JSON output.

One quirk of the Google Geocoding API, though, is that all of the resulting municipality names are only in English. Try for example queries for Wien or 東京 (Tokyo). Since we want our suggestions to only add information to our input, not replace the input entirely (and especially not in another language), we’ll then only take results which have the input as an initial substring. On the other hand, if none of the results have the input as a proper prefix of the return value, we will take the geocoding information from the first result but with the original input as the display text. Such results will have a markedly lower score.¹

As this is the address nountype, we’ll penalize results which do not have detailed information such as street address or town-level information. All of this is very easy to judge as every result from the API has a geocoding accuracy value.

The best laid plans of mice and men…

I spent a good few hours this afternoon and evening attempting to implement this new family of nountypes, including this new nountype_geo_address, but also nountype_geo_subregion, nountype_geo_region, and nountype_geo_country. Some of the quirks of the weather and map commands, however, have prevented me from completely replacing the legacy noun_type_address and noun_type_geolocation described above. I hope to continue this work again soon and actually make this transition, ideally before 0.5.2.

Look forward to one (or maybe two?) more episode(s) of Nountype Quirks where I hope to definitively explain, analyze, and tweak matchScore, the scoring algorithm which underlies the majority of the nountypes in Ubiquity. As always, I look forward to your comments and feedback.

Bonus: Where’s Jono?

It turns out that noun_type_async_address was recognizing “Jono” as an address because Jono is actually a location afterall! Not only that, but Jono is in Japan!!

You clearly can’t take Japan out of Jono, but it turns out you can’t take Jono out of Japan either.

Related posts:

1. Nountype Quirks: Day 2
2. Nountype Quirks: Day 1
3. Judging Noun Types

Related posts brought to you by Yet Another Related Posts Plugin.

Today I’m continuing the process of reviewing and tweaking all of the nountypes built-in to Ubiquity. For a more respectable introduction to this endeavor, please read my blog post from a couple days ago, Judging Noun Types and my status update from yesterday, Nountype Quirks: Day 1.

Note: this blog post includes a number of graphs using HTML/CSS formatting. If you are reading this article through a feed reader or planet, I invite you to read it on my site.

noun_type_twitter_user

Let’s begin again by considering the suggestions and scores that a variety of different inputs to this nountype return and see what quirks we find.

To test this nountype, I made sure I had logged into Twitter once with the login mitchoyoshitaka.

input	suggestion
mitcho	mitchoyoshitaka	0.85
	mitcho	0.5
mitchoyoshi	mitchoyoshitaka	0.94
	mitcho	0.5
test	test	0.5
テスト	none
hello world	none
@test	none

As nountypes go, this is looking pretty good. For usernames which look like logins we’ve saved before, we’re using matchScore to get decent differential scores.¹ It’s even ruling out impossible twitter username strings, according to Twitter’s own restriction:

One possible improvement we could make is to let @ strings be accepted. I went ahead and made this improvement. The initial @ will be stripped off and then will be checked as normal, but the final score will receive a slight boost using an nth root formula. The twitter command was also updated to deal with inputs with and without the initial @.

input	suggestion
mitcho	mitchoyoshitaka	0.85
	mitcho	0.5
@mitcho	@mitchoyoshitaka	0.88
	@mitcho	0.57
test	test	0.5
@test	@test	0.57

Although the noun_type_twitter_user nountype is currently most used by the built-in twitter command to specify the user’s username, in theory it could also be used for example in a command which pulls up another user’s tweets. With that in mind, perhaps in the future we could check the browser history and/or bookmarks for entries of the form http://twitter.com/... and suggest those as well (trac #846).

noun_type_number

input	suggestion
text	none
0.5	0.5	1
0.5.1	none

This nountype has an incredibly simple job and does it with ease. I’m going to leave it alone.

noun_type_date and noun_type_time

noun_type_date and noun_type_time both use the magical Date.parse method to parse date- and time-like strings. Let’s first take a look at some of its suggestions:

input	date suggestion	time suggestion
June 8th 5pm	2009-06-08	05:00 PM	1
5pm	2009-07-30	05:00 PM	1
5	2009-07-05	12:00 AM	1
June 8th	2009-06-08	12:00 AM	1
today	2009-07-30	12:00 AM	1
now	2009-07-30	02:40 PM	1
5pm is a good time	none	none

The quirks in these outputs can be summed up into these two factors:

1. There is no differential scoring at all.
2. Both nountypes parse the input with Date.parse and then just spit out the date or time components of the result. Thus time-only inputs get the default date and date-only inputs get the default time with equal scores.

I just rewrote both nountypes and also added a new noun_type_date_time. Here are some of the features of the new implementation:

1. If the input only contains digits and spaces, it is marked down.
2. With the exception of the outputs ‘today’ and ‘now’, if the resulting Date object’s date is today, its date suggestion is scored lower; equivalently for time being the default value, “12:00 AM”.
3. Scores (with the exception of ‘today’ and ‘now’) which are shorter than the output string get a slight penalty. This factor reflects the intuition that a longer output than input means some generic information was added and thus there is less confidence in the output.

Here’s what some of the inputs give now:

input	suggestion
June 8th 5pm	date: 2009-06-08	0.7
	time: 05:00 PM	0.7
	date_time: 2009-06-08 05:00 PM	0.86
5pm	date: 2009-07-30	0.27
	time: 05:00 PM	0.81
	date_time: 2009-07-30 05:00 PM	0.49
5	date: 2009-07-05	0.53
	time: 12:00 AM	0.19
	date_time: 2009-07-05 12:00 AM	0.34
June 8th	date: 2009-06-08	0.95
	time: 12:00 AM	0.35
	date_time: 2009-06-08 12:00 AM	0.58
today	date: 2009-07-30	1
	time: 12:00 AM	0.45
	date_time: 2009-06-08 12:00 AM	0.7
now	date: 2009-07-30	0.7
	time: 12:00 AM	1
	date_time: 2009-06-08 04:34 PM	1

In addition, looking to the future we’d like to make nountypes localizable as well, and these two nountypes in particular will surely require some good thinking and planning to make localizable.

noun_type_email and noun_type_contact

noun_type_email and noun_type_contact are two closely related nountypes. noun_type_email simply validates email address-looking strings, while noun_type_contact will return the noun_type_email suggestions and additionally return contacts from GMail if available.

The first thing to note is that I’ve often found the GMail contact lookup to be finicky in my own use. Reading through the code, I discovered the solution: GMail must either be open in a tab or you must use the “stay signed in” option and close the GMail tab.² With this mystery solved, and some code cleanup done to this contact fetching, let’s take a look at some example suggestions: (suggestions overlapping with noun_type_email are not listed here)

input	suggestion
aza@m	aza@mozilla.com	0.42
jono	jdicarlo@mozilla.com	0.28
jdicarlo	jdicarlo@mozilla.com	0.19

In general, we see that these scores all look pretty poor. In particular, though, note that the “jono” input yielded a higher score for the same suggestion than “jdicarlo”, even though “jdicarlo” is longer and thus, intuitively, has more informational content and should maybe do better. Digging into the code I realized why this is. It was computing the scores by comparing “jono” and “jdicarlo” not simply to “Jono DiCarlo” and “jdicarlo@mozilla.com” respectively, but to the combined string “Jono DiCarlo <jdicarlo@mozilla.com>”. Now with this change in place, both the email address and name are analyzed individually and, due to the way nountype detection works in Parser 2, no duplicates are returned. Here are the updated results:

input	suggestion
jono	jdicarlo@mozilla.com	0.83
jdicarlo	jdicarlo@mozilla.com	0.85

That’s much better!

Now let’s consider the suggestions from noun_type_email. Here are what they originally looked like:

input	suggestion
bpung	none
bpung@m	bpung@m	1
bpung@mozilla.com	bpung@mozilla.com	1

noun_type_email is based on a very robust regular expression for RFC 2822. Unfortunately this means that it completely rules out strings such as “bpung” which could be a proper prefix of an email address—something that I’ve advocated for avoiding before (see footnote 2 of Judging Noun Types). Moreover, due to a quirk of how nountypes based on regular expressions are scored, all results are given the score of 1.

I just committed a change so that this behavior is improved. The new version accepts strings which match the username part of the email address spec sans @ and domain, but with a great score penalty.³ Moreover, domains which do not have a final label (the top level domain) with more than one letter (unless it’s an IP address) or do not have any periods (.) in the domain will be penalized as well. Here’s what the same inputs produce now:

input	suggestion
bpung	bpung	0.3
bpung@m	bpung@m	0.8
bpung@mozilla.com	bpung@mozilla.com	1

Same time, same channel

I hope this post sheds light on the many changes I made together as well as the underlying thought process. If you don’t agree with any particular fix or analysis, please comment! I’ll be back again tomorrow with another installment of Nountype Quirks. Stay tuned!

Related posts:

1. Nountype Quirks: Day 1
2. Judging Noun Types
3. Big Issues and Small Issues with Parser 2

Related posts brought to you by Yet Another Related Posts Plugin.

Today I began the process of going through all of the nountypes built-in to Ubiquity using the principles and criteria I laid out yesterday—a task I’ve had in planning for a while now. As I explained yesterday, improved suggestions and scoring from the built-in nountypes could directly translate to better and smarter suggestions, resulting in a better experience for all users. Here I’ll document some of the nountype quirks I’ve discovered so far and what remedy has been implemented or is planned.

Note: this blog post includes a number of graphs using HTML/CSS formatting. If you are reading this article through a feed reader or planet, I invite you to read it on my site.

noun_type_percentage

Here’s what a few different inputs originally returned:

input	suggestion
20	20%	1
20%	20%	1
0.2	20%	1
0.2%	20%	1
20.0	2000%	1
2 hens in the garden	2%	1

Let me highlight a couple obvious quirks:

1. In certain cases, where the numerical expression includes a decimal and is less than one, it is interpreted as a proportional, rather than percent, value, e.g. “0.2” → “20%”. “0.2%” is not even an option. This is the case even when explicitly adding a % sign.
2. All suggestions, including those where the numeral was extracted from a long string of text (e.g. “2 hens in the garden”), get the same score of 1.

I just committed a fix so noun_type_percentage now…

1. Counts the number of characters in the input which match [\d.%] and caps the score by (number of acceptable characters)/(length of input).
2. Strings which do not include “%” get a 10% penalty.
3. In the case of decimals less than 1 without a % sign, the proportion interpretation is also suggested (e.g. “0.2” → “20%”) in addition to the original suggestion (“0.2%”), but with a slight penalty.

Here is what they now return:

input	suggestion
20	20%	0.9
20%	20%	1
0.2	0.2%	0.9
	20%	0.81
0.2%	0.2%	1
20.0	20%	0.9
2 hens in the garden	2%	0.05

noun_type_tag

Here’s what a few different inputs originally returned. Keep in mind that currently in this test profile, the preexisting tags are “animal”, “help”, “test”, and “ubiquity”.

input	suggestion
animal	animal	0.3
mineral	mineral	0.3
anim	animal	0.7
	anim	0.3
help, test, ubiq	help,test,ubiquity	0.7
	help,test,ubiq	0.3
google, yahoo, ubiq	google,yahoo,ubiquity	0.7
	google,yahoo,ubiq	0.3
google, , yahoo	google,yahoo	0.3

Here are a few of noun_type_tag’s quirks:

1. There are only two scores ever given out: 0.3 and 0.7.
2. Only the last tag in the list and whether it exists or not is taken into account.
3. When the last tag is incomplete, the completion is suggested with a higher score, but if the last tag is exactly equal to an existing tag, it gets the lower score.

Ideally, we want noun_type_tag to look at each of the tags given to it, with higher scores for when there are more preexisting tags and fewer new ones. Keep in mind, though, that we only have to suggest the completion of the very last tag as that may be one where the user hasn’t completed typing yet… for earlier tags, we can assume (safely or not) that the user placed the comma where they meant to. We can’t teach Ubiquity to read minds, after all.¹

With this in mind, I just made a change to noun_type_tag which aims to follow these principles. The basic idea is that we start with a base score of 0.3 but then raise it via nth root for every tag in the sequence which is preexisting. Here’s what the same inputs return now. Recall that the preexisting tags are “animal”, “help”, “test”, and “ubiquity”.

input	suggestion
animal	animal	0.55
mineral	mineral	0.3
anim	animal	0.55
	anim	0.3
help, test, ubiq	help,test,ubiquity	0.86
	help,test,ubiq	0.74
google, yahoo, ubiq	google,yahoo,ubiquity	0.55
	google,yahoo,ubiq	0.3
google, , yahoo	google,yahoo	0.3

noun_type_awesomebar

input	suggestion
moz	http://www.mozilla.com/	0.8
	https://wiki.mozilla.org/Labs/Ubiquity/ Parser_2_API_Conversion_Tutorial	0.8
	http://en-us.start3.mozilla.com/ firefox?client=firefox-a&rls= org.mozilla:en-US:official	0.8
	http://en-us.www.mozilla.com/en-US/firefox/about/	0.8

There are a couple quirks here:

1. All suggestions are returned with the same scores.
2. The nountype returns the URL of the entry as the HTML-formatted result and the title as the text-formatted result, which clearly does not make sense. However, it’s not clear to me whether the title, URL, or some combination of both is what we should be returning as the suggestion text presented to the user.²

I just rewrote noun_type_awesomebar to actually do some differential scoring. This new version also presents the URL or title depending on whichever had a better match using the matchScore function.³

input	suggestion
moz	www.mozilla.com	0.7
	https://wiki.mozilla.org/Labs/Ubiquity/ Parser_2_API_Conversion_Tutorial	0.63
	http://en-us.start3.mozilla.com/ firefox?client=firefox-a&rls= org.mozilla:en-US:official	0.61
	http://en-us.www.mozilla.com/en-US/firefox/about/	0.6

noun_type_url

The purpose of noun_type_url’s suggest function is two-fold: first, to accept strings which may look like a URL and, second, to suggest URL’s from the history just like noun_type_url, but only based on URL matches and not title matches.⁴ Here are a few sample inputs:

input	suggestion
moz	http://www.mozilla.com/	0.9
	http://moz	0.5
	https://wiki.mozilla.org/Labs/Ubiquity/ Parser_2_API_Conversion_Tutorial	0.9
	http://en-us.start3.mozilla.com/ firefox?client=firefox-a&rls= org.mozilla:en-US:official	0.9
	http://en-us.www.mozilla.com/en-US/firefox/about/	0.9
test	http://test	0.5
http://	http://	0.5
http:	http:	0.5
http	http	0.5
_test	http://_test	0.5
hello world!	http://hello world!	0.5

Oh, where to begin!? Here are some initial quirks… it’s possible that you could think of more!

1. There is no differential scoring… only 0.9 for suggestions from history and 0.5 for URL-like strings.
2. A number of invalid domain names are being accepted and turned into suggestions (“hello world!”, “_test”, etc.).
3. It’s trying to be smart by suggesting “http://” as a default URI scheme but doing so even for prefixes (initial substrings) of the word “http” itself.

With these thoughts in mind, I just took a first stab at improving this situation. Here are some features of the new implementation:

1. History entries are scored in the same way as in noun_type_awesomebar, using matchScore.
2. URLs without an explicit URI scheme (like “http://”) get a 10% penalty.
3. “http://” is only suggested if one of a long list of common URI schemes are not detected.
4. It repairs schemes which are missing a slash or two, suggesting for example “http:hello.com” → “http://hello.com”.
5. It actually uses Firefox’s own IDNService to check if the domain name is a valid internationalized domain name. If it’s an IDN as opposed to LDH (“letters, digits, and hyphens”), it gets a 10% penalty. If it’s not even a valid IDN, it is ruled out (see last two example inputs below).
6. There are also penalties for only being a domain name with no path and for the domain not having any periods (.) in it.

Here is what our suggestions now look like:

input	suggestion
moz	http://www.mozilla.com/	0.6
	http://moz	0.65
	https://wiki.mozilla.org/Labs/Ubiquity/ Parser_2_API_Conversion_Tutorial	0.63
	http://en-us.start3.mozilla.com/ firefox?client=firefox-a&rls= org.mozilla:en-US:official	0.61
	http://en-us.www.mozilla.com/en-US/firefox/about/	0.6
test	http://test	0.65
http://	http://	1
	shttp://	0.75
http:	http://	0.9
	shttp://	0.7
http	http://	0.72
	https://	0.71
	shttp://	0.68
	http://http	0.65
_test	none
hello world!	none

See you tomorrow~

Alright, enough nountype wrangling for one day. I’ll be back again tomorrow for another installment.

Related posts:

1. Localizing Commands for Ubiquity 0.5
2. Judging Noun Types
3. A Demonstration of Ubiquity Parser 2

Related posts brought to you by Yet Another Related Posts Plugin.

Different arguments are classified into different kinds of nouns in Ubiquity using noun types.¹ For example, a string like “Spanish” could be construed as a language, while “14.3” should not be. These kinds of relations are then used by the parser to introduce, for example, language-related verbs (like translate) using the former argument, and number-related verbs (like zoom or calculate) based on the latter. Ubiquity nountypes aren’t exclusive—a single string can count as valid for a number of different nountypes and in particular the “arbitrary text” nountype (noun_arb_text) will always accept any string given.

In addition to the various built-in nountypes, Ubiquity lets command authors write their own nountypes as well.

The functions of a noun type

Nountypes have two functions: the first is accepting and suggesting suggestions and the second is scoring.

Accepting and suggesting

Nountypes don’t just have to accept the exact string they were given—they can also return suggestions which are based on that input. For example, the noun_type_language can take the input “span” and return “Spanish.” A nountype can return multiple suggestions which may or may not include the trivial suggestion, i.e. the original input as is. If there is no way that that input could possibly be part of an accepted value, it should return no suggestions, i.e. [].²

Scoring

Ubiquity 0.5 with Parser 2 introduced the notion of a nountype suggestion score. For example, two different nountypes can accept the same input, but with different scores. Scores range from 0 to 1 where 1 is a perfect or exact suggestion and 0.1 or so is a very very improbable suggestion.³ These scores are used in the scoring of parses. Because verbs specify certain nountypes for each of their arguments, the scores that individual nountypes return for each argument are a crucial component of the scoring algorithm and can even determine whether a parse is returned or not.

With this in mind, you may be tempted to make your nountype return a score of 1 on any input so your verb will show up in the suggestions highly. While this would work, it will only act to make your verb annoying and a poor Ubiquity citizen. Appropriate scores must be given to noun suggestions, with higher values reflecting confidence and lower values reflecting imprecision. But how exactly do you figure out what’s an appropriate value?

Judging nountypes with the Nountype Tuner

The Nountype Tuner is a new tool I’ve been building to help both Ubiquity core developers and command authors to check their nountypes against others and to “tune” their behavior and scores. The nountype tuner will take your input and throw it against all of the nountypes referenced in your active verbs and display the suggestions returned with their scores. You can think of it as the Playpen’s little sister.

The Nountype Tuner can be found at chrome://ubiquity/content/tuner.html, though I am pretty sure it is broken in Ubiquity 0.5 and 0.5.1. It has been fixed now and I will make sure it’s in good shape for 0.5.2.

The heart and soul of the Nountype Tuner is this scale:

This scale tells you, in plain English, what different scores represent and correspond to, in two sets of vocabulary: “in terms of a guess” and “in terms of a match.” While still subjective, this scale helps developers just different input/output pairs and their scores. For example, “lian” → “http://lian” is given 0.5, so it’s an okay guess or a possible match… does that seem right to you? Or “lian” → “Italian” being between “okay” and “good.” Appropriate? We can look at such statements, decide how we feel about them, and tweak if necessary.

Good nountype scores have roots

CC-BY Aaron Escobar

…not that kind of root, but more like this kind of root… let me explain…

When comparing the scores that individual nountypes return for different inputs, we must compare those scores within the same nountype’s family of suggestions to see if higher scores truly correspond to higher confidence. For example, the language nountype should give the suggestion “French” for both the inputs “f” and “fren,” but the scores of these suggestions should be different—i.e. the score of “f” → “French” should be much lower than the score for “fren” → “French,” reflecting the additional informational value. We refer to this relation of the scores of successive prefixes of a single suggestion all returning that same suggestion as the score curve and in general it should be non-decreasing.⁴

One could say the most trivial score function then is the linear one. For a series of converging prefixes of the same suggestion (“Dutch”), under a linear approach we could naively let the score be (length of the input)/(length of the suggestion), as below:

This linear model is represented below by the black line.

The problem with the linear model is that earlier transitions (additional keystrokes) add more information than the later ones. Once we’ve entered “dutc,” after all, we would like to be pretty darn sure that we mean “Dutch,” so the score difference between “dutc” and “dutch” should be less than the score difference between, say, “d” and “du.” We want a score curve that looks more like the solid or dotted red lines above.

For this reason, I strongly advocate the incorporation of an nth-root in the score computation. Nth-rooted score functions over [0,1] have the feature that they are increasing but also that earlier transitions affect the score more than later ones, which is exactly what we’d like to see. (The solid red line above is x^1/2 and the dotted one is x^1/3.)⁵

Conclusion

Properly tuning both the built-in nountypes and custom nountypes is crucial to producing more accurate and relevant parse suggestions. I’ll be using the principles and criteria laid out above, combined with the new Nountype Tuner, to tune the built-in nountypes (trac #746) in the coming days in preparation for our 0.5.2 release. I invite you to use the Nountype Tuner in 0.5.2 to tune your custom nountypes as well.

Related posts:

1. Scoring and Ranking Suggestions
2. Ubiquity Localization: What’s New, What’s Next
3. Ubiquity Parser: The Next Generation Demo

Related posts brought to you by Yet Another Related Posts Plugin.

As we look to move forward with incorporating the next generation parser into Ubiquity proper, it thus becomes important to take a look at the current command ecosystem to see how possibly disruptive this move will be. To this end last night I wrote a quick perl script to scrape the commands cached on the herd and get some quantitative answers to my questions.

(1577 different verbs were analyzed. None of these computations below are weighted by feed popularity.)

Q: Are there a lot of commands which use more than one argument?

A: The vast majority (>85%) of commands take one or no arguments, requiring no modifiers. Only those remaining 15% will require a switch to refer to different arguments by semantic role.

Q: Do many commands introduce custom noun types?

A: 147 different noun types (lumping anonymous inline objects as one type) were detected. The vast majority of all takes (direct object) arguments were of type noun_arb_text, although many modifiers arguments used custom noun types. The other standard (built-in) noun types are well represented as well, with noun_type_language coming in at second place. Here’s a chart with all the noun types which had more than one use.

Q: Are commands with modifiers using natural-language delimiters?

A: Most of the modifiers detected were English prepositions such as “from”, “to”, “as”, “with”, but other words were also seen such as “title”, “type”, “username”, and “message” and even a handful of commands with symbols such as “@”, “>”, or “#”.

Related posts:

1. Writing commands with semantic roles
2. Ubiquity Parser: The Next Generation Demo
3. Ubiquity in Firefox: Focus on Japanese

Related posts brought to you by Yet Another Related Posts Plugin.