Preposition Class Analyses

(Under Development)

The representative instances collected in The Preposition Project (TPP) Pattern Dictionary of English Prepositions (PDEP) provide a comprehensive view of prepositions and an opportunity for examining the landscape of meaning expressed by prepositions. More specifically, the preposition senses and patterns can be aggregated into classes or clusters of semantic relations. Each class may be viewed as a coarse-grained set of meanings. Each class may then be analyzed in detail to provide a fine-grained set of meanings for the class. TPP has identified 12 classes, which are grouped and described briefly below, each of which contains a link to the fine-grained dimensional analysis for that class. This compares to 33 clusters assigned by Stephen Tratz (A Fast, Accurate, Non-Projective, Semantically-Enriched Parser) and 32 general semantic relations assigned by Vivek Srikumar (Modeling Semantic Relations Expressed by Prepositions). The number of classes or categories is undergoing refinement as instances are being examined; see below for a description of this process and a description of the class tables.

Classes

• Activity: This category embraces prepositional senses that require the name of some (usually human) activity for complementation. By implication, agents appear somewhere in the sentence in which these are found, occasionally as a point of attachment (especially when the PP follows a copula and is the entire predicate). There are many instances, however, especially in complex sentences, where the agent is not so closely related to theactivity that appears as the complement of the PP. This class contains 35 senses under 24 prepositions. This category contains the following subclasses: {Ongoing Activity; Proposed Activity; Activity Avoided}
• Backdrop: Prepositional senses in this category are very often couched in disjuncts and subjuncts, i.e., prepositional phrases serving as sentence adverbs or quasi-independent observations, describing circumstances or features that are present as a way of characterizing or coloring how the subject and predicate are interpreted. This class contains 63 senses under 52 prepositions. This category contains the following subclasses: {Supplementing; Contrasting {Negative}}
• Cause: The complements in this category identify the cause for something – sometimes for the governor, but also for other things named in the sentence. Cause here is broadly interpreted to refer to a Cause–Purpose spectrum that includes Cause, Reason, Motive, Purpose, Destination, and Target. There are 89 cause senses under 60 prepositions. This category contains the following subclasses: {Cause, Reason, Motive {Cause; Reason, Motive}; Purpose, Intended Destination; Recipient, Goal, Target {Recipient; Beneficiary {Employer}; Goal, Target}; Source, Origin}
• Agent: This category includes prepositional complements denoting an agent – that is, a doer of some action. All such sentences could, in theory, be rewritten in a way that would make the agent the subject of a sentence, thus eliminating the prepositional construction. This rewrite is to be taken in a very broad sense here: not merely rearranging the words present, but expressing the same idea using different words. It may properly be viewed as a subcategory of Cause. This class contains 58 senses under 33 prepositions. This category contains the following subclasses: {Direct Agent; Indirect Agent; Involved Party {Possessor; Attribute}}
• MeansMedium: This category takes in all prepositional senses where the complement identifies the means by which, or the medium through which, something happens or is done. This category roughly corresponds to a grammatical instrumental case. This class contains 94 senses under 60 prepositions. This category contains the following subclasses: {Manner {Negative}; Means {Negative}; Instrument {Negative}; Medium; Agentive {Negative}; Stimulus}
• Membership: This category is for senses that establish a relationship of membership between the governor and complement, wherein either can be a member of the genus that the other represents; the salient thing is that the preposition (and very often, along with other words in proximity) state that the relationship is one of genus and species. This class contains 49 senses under 33 prepositions. This category contains the following subclasses: {Group; Species}
• Exception: This category of prepositional senses includes mostly subjuncts and disjuncts that indicate something constituting an exception or exclusion to what is predicated in the related clause. This class contains 30 senses under 26 prepositions. It may properly be viewed as a subcategory of Membership. This category contains the following subclasses: {Exception; Exclusion}
• Scalar: Scalar prepositions hold complements that have reference to a scale. Most often, they identify a point on a continuum, but they may also establish the existence of a scale, or the top or bottom values on one. The complements of many scalar prepositions are quantities or have some entity characterized numerically. There are 127 scalar senses under 74 prepositions, This category contains the following subclasses: {Scale Identification; Relational {Equivalence; Greater than; Less than}; Age; Mathematical}
• Spatial: This class is used to express properties of a location or to use the complement (an entity) as a reference point for some other entity or for some stative or eventive expression. There are 251 spatial senses under 112 prepositions in this class. This category contains the following subclasses: {Simple Position {As a destination; As a place of origin; As a conveyance}; Relative Position {Vertically {Above; Below; Equal}; Horizontally {Behind; Before; Beside; In the presence of}}; Path (Passage); Orientation; Pervasiveness}
• Tandem: This category contains senses that do not fall easily into some other category and that establish some sort of relationship between the complement and the point of attachment (governor) or the complement and another sentence element. This class contains 72 senses under 39 prepositions. This category contains the following subclasses: {CoParticipants; Opponent; Fulfillment of the Governor {End State}}
• Temporal: These prepositions establish a temporal relationship between the complement and some other sentence element, sometimes the point of attachment or governor, sometimes the subject or some other object. It is broken down further into senses that denote a point in time and senses that denote a period or duration. This class contains 93 senses under 75 prepositions. This category contains the following subclasses: {Time Position {Simple time point {Time origin; Time finished}; Time preceding; Time following}; Duration {Period when something persists or happens}}
• Topic: This category contains many synonymous and related prepositions that establish a topic about which other sentence elements make some statement. In general, the complements of all prepositions in this class identify the subject of discussion and each preposition can be paraphrased as on the subject of. This class contains 54 senses under 44 prepositions. This category contains the following subclasses: {Focus of reference; Focus of attention; Focus of connection}

Special Class

• Tributary: This category is only for the small group of prepositions in the inventory that are merely orthographic variants of some other preposition and can substitute for any sense of that preposition. These prepositions have been given sense inventories corresponding to the base preposition. This class contains 24 senses under 24 prepositions.

Classes Merged

• Barrier: The complement represents a physical thing that stops action. There is some kinship with Target, below. This category is similar, except that the barrier may not be an intentional stopping place or destination, whereas the target is. This class contains 6 senses under 5 prepositions. This class was merged with Spatial, since the complements all specify a location where the governor occurs.
• Consequence: This class contains 3 senses under 3 prepositions, all identifying a penalty resulting from the governor. These have all been moved to the Tandem category under the End State subcategory.
• Doubles: Doubles is confined to only two prepositions (between and among) whose complements, in the senses included, are always dual or plural, since the prepositions essentially stipulate a relationship embracing two or more things. Typically the point of attachment indicates the nature of the relationship. This class contains 8 senses under 2 prepositions. Senses in this category have been merged into Tandem, Spatial, Temporal, Scalar, and Membership, reflecting the affinity of their senses to these classes.
• Party: This category is for senses whose complement is a person (though not the main actor, and so not directly classifiable under Agent). Despite this, the category has been merged into Agent as a subcategory Involved party. In principal, all SRTypes that contain Party can be placed in this category; if they are assigned elsewhere it is because their placement reflects a more important or useful classification. This class originally contained 9 senses under 9 prepositions.
• Possession: A relatively small category for complements representing something that is owned, held, or worn by the complement. All such sentences could, in theory, be written with the complement or POA as subject and some form of the verb have. By implication then, this category was absorbed into Agent, subsumed under Involved Party, where no direct agency in involved. This class contains 8 senses under 5 prepositions.
• Quantity: This category holds complements that can be expressed as a number or some other quantity. Quantity prepositions have a quantity as the complement, but the type of quantity is established by the preposition itself or by some other element in the sentence, usually the governor or point of attachment. This class contains 39 senses under 31 prepositions. Senses in this class have been merged into Scalar prepositions.
• Substance: The complements identify some uniform substance or thing that constitutes the contents or constituents of the POA. This class contains 3 senses under 2 prepositions. (These senses have been moved to the Membership category.)
• Target: This smallish category is for senses that identify the object or target of some action. The POAs are usually verbs, though they can also be adjectives when the adjective describes some attitude or feeling that is directed or felt toward a particular person or thing. The prepositions included are a rather small set, and include nearly all the senses of toward, which is the targeting preposition par excellence. This class contains 18 senses under 11 prepositions. Senses in this category were moved to other categories, primarily the Cause category, since they seem to be at the end of the cause/purpose spectrum, and to the Spatial, Tandem, and Scalar categories.
• Void: This category is for senses which note a complement designated as missing or not present by other sentence elements. This class has been merged into Backdrop, as a Negative contrasting subcategory. This class contains 4 senses under 4 prepositions.

Procedure for Class Analysis

The analysis of preposition classes proceeds from a bottom-up examination of the TPP corpus instances for each individual sense. The particular sense under investigation is opened in PDEP. The objective is to complete its behavioral characterization, identifying the types of complements and the governors, the feature selectors for the complements and the governors, the TPP class and relation, the Tratz cluster, and the Srikumar semantic relation. This is done by opening the OEC instances, the FrameNet instances (if any), and the TPP instances. While an attempt is made to enter as much behavioral information as possible, a particular focus is to understand the nuance in meaning within the TPP class. In general, this analysis proceeds for the senses that have been identified for one class, with the objective of building an analysis of the nuances in that class. When a sufficient number of senses in a class has been analyzed and the dimensions of the class begin to emerge, this analysis is linked into PDEP. Then, whenever examining a sense that has a preliminary class analysis, the PDEP sense will have an Analysis menu item that can be clicked to bring up the analysis. This analysis will identify all senses in that class, with a discussion of the general characteristics of the class and any dimensional analysis for the class.

Description of Class Summary Tables

For several of the classes, the links lead to an in-depth discussion of the class. For all the classes, a current summary table is generated. For those with a discussion, the table appears after the discussion.

Each summary table includes a list of all the preposition senses in a given TPP class. A row in this table identifies the Preposition, the Sense number, and the TPP relation (labeled Srtype). The Count column indentifies the number of CPA instances that have been tagged with this sense. The percent column (Pct) identifies the percent of the instances for the preposition that have been tagged. When the percent is less than 100 percent (i.e., not all instances have yet been tagged), there is the possibility that more instances will be tagged with this sense.

The last column in a row is a normalized frequency (NF). This is an estimate of the number of instances per one million prepositions in the written portion of the British National Corpus. As discussed in detail elsewhere, the instances for each preposition is a sample drawn from the BNC. The target sample size was 250, with a larger sample for the most common prepositions with many senses. When the number of instances in the BNC was fewer than 250, all instances were used. When the samples were drawn, the total number of instances for each preposition was recorded (b_i). When summing this number over all prepositions, the total N was 5,391,042. (For of and in, the total number of instances was 1,000,000, so that the estimate for the total is likely somewhat higher. As a rough order of magnitude, this is not likely to be very signficant.) To compute the normalized frequency for each sense, we first compute the proportion of the preposition's instances that have been tagged with the specific sense, i.e., p_i = c_i/n_i, where c_i is the count tagged for the sense and n_i is the size of the sample for the preposition. Next, f_i = p_i*b_i is computed as an estimate of the frequency of instances in the BNC that have this sense. Finally, nf_i is computed as (f_i/N)*1000000.

A minor adjustment was made for very infrequent occurrences. All prepositions and all senses have been attested, but they may not appear in the instances we have drawn. The frequency in the BNC (b_i) is assumed to be at least 1. The count tagged in our sample (c_i) is assumed to be at least 1. The sample size in the CPA for the preposition (n_i) is assumed to be at least 1. For cases where all these conditions hold, the estimated frequency per million prepositions (nf_i) is 0.19 (i.e., less than 1/5th of an occurrence per million prepositions).

References

1. Quirk, R., Greenbaum, S., Leech, G., and Svartik, J. 1985. A Comprehensive Grammar of the English Language. Longman: New York.