This document describes ITVENSES, a symbolic system for aspect-based sentiment analysis. It walks through an example of how ITVENSES analyzes a sentence in Italian, tagging parts of speech, determining syntax and semantics, identifying aspects and polarities, and outputting an evaluation. ITVENSES uses sieves and rules to analyze sentences at different levels of representation and combine analyses to determine overall sentiment. Performance results on test sets are provided, showing ITVENSES achieves good accuracy for binary and multiclass sentiment classification tasks.
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Present eval
1. ITVENSES - A SYMBOLIC
SYSTEM FOR ASPECT
BASED SENTIMENT
ANALYSIS
RODOLFO DELMONTE
DIPARTIMENTO DI STUDI LINGUISTICI E CULTURALI COMPARATI
UNIVERSIT CA FOSCARI
EMAIL: DELMONT@UNIVE.IT WEBSITE: RONDELMO.IT
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8. WALKTHROUGH EXAMPLE
FROM ITGETARUNS TO ITVENSES
Try Match Aspect/s from refexs, i.e. Nouns, Verbs,
Adjectives - bagno aspect 2; mancare aspect 3
Try Match Polarity/ies from refexs, i.e. Nouns,
Verbs, Adjectives - mancare marked as negative
sievesall: recomposes aspects and polarities which
can be multiple for every sentence in a text
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9. WALKTHROUGH EXAMPLE
FROM ITGETARUNS TO ITVENSES
sievescheck: invertpols (invert polarities for the current aspect)
sievescheck: focalizers (spots focalizers, minimizers, downtoners)
sievescheck: checknegpriv (finds negation and its scope)
sievescheck: syntax sieves (deletes current aspect assignment identifiers)
Ind=2;Ind=3;Ind=6;Ind=7 - bagno Ind=2 (deleted)
Ind=3 albergo;hotel;struttura & centro;centrale;a_due_passi
Ind=2 camera;moquet;asciugamano;stanza;ambiente;bagno;letto &
spazioso;comodo & + pulito
Ind=7 strada;piazza & rumoroso
Ind=7 arrivare;raggiungere & difficile;distante;scomodo;scarso
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10. WALKTHROUGH EXAMPLE
collapseall: recovers all clause level analysis of the current
sentence both at propositional and at subjective/factivity level and
collects them together
now each evaluation term is made up by a text index - a set of
semantic propositional level representations for that sentence - one
aspect assignment - one associated polarity assignment, made up
by a positive and a negative slot
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11. WALKTHROUGH EXAMPLE
AUGMENTED PREDICATE ARGUMENT STR.
1240342904-[
1240342904_1-mancare(neg,statement,dentifricio-dentifricio-3,
bagno-bagno-5)]-
[mancare]- Aspect seeds
[[],[Manca]]- Polarities: Positive+Negative
3] Aspect Identifier
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12. WALKTHROUGH EXAMPLE
evalothers: evaluates sentences marked with aspect n.8 and
associates semantic representations
reduceevals: collapses evaluation terms for the same sentence
with identical values
othersieve: sieves and modifies aspect value using combinations
of aspect assignments present at text level; fires preferences for
combined aspect values which modify one or more value
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13. WALKTHROUGH EXAMPLE
comparevals: sieves and modifies those texts declaring tutto bene
or the opposite with an all aspects positive/negative marking
checks for texts made up by a couple of aspects each evaluated to
the contrary
checks for texts which have a semantic propositional level analysis
as nonfactual or as negated and marks them with negative polarity -
if + double negations
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14. WALKTHROUGH EXAMPLE
Outputs the resulting 0/1 string
1240342904-[0,0,0,0,0,0,1,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0]-true
www.rondelmo.it
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