Abstract: Conversations in social media often contain the use of irony or sarcasm, when the users say the opposite of what they really mean. Irony markers are the meta-communicative clues that inform the reader that an utterance is ironic. We propose a thorough analysis of theoretically grounded irony markers in two social media platforms: $Twitter$ and $Reddit$. Classification and frequency analysis show that for $Twitter$, typographic markers such as emoticons and emojis are the most discriminative markers to recognize ironic utterances, while for $Reddit$ the morphological markers (e.g., interjections, tag questions) are the most discriminative.

Introduction: With the advent of social media, irony and sarcasm detection has become an active area of research in Natural Language Processing (NLP) BIBREF0 , BIBREF1 , BIBREF2 , BIBREF3 . Most computational studies have focused on building state-of-the-art models to detect whether an utterance or comment is ironic/sarcastic or not, sometimes without theoretical grounding. In linguistics and discourse studies, BIBREF4 (2000) and later BIBREF5 (2010) have studied two theoretical aspects of irony in the text: irony factors' and irony markers. Irony factors are characteristics of ironic utterances that cannot be removed without destroying the irony. In contrast, irony markers are a meta-communicative clue that “alert the reader to the fact that a sentence is ironical” BIBREF4 . They can be removed and the utterance is still ironic. In this paper, we examine the role of irony markers in social media for irony recognition. Although punctuations, capitalization, and hyperboles are previously used as features in irony detection BIBREF6 , BIBREF7 , here we thoroughly analyze a set of theoretically-grounded types of irony markers, such as tropes (e.g., metaphors), morpho-syntactic indicators (e.g., tag questions), and typographic markers (e.g., emoji) and their use in ironic utterances. Consider the following two irony examples from INLINEFORM0 and INLINEFORM1 given in Table TABREF2 . Both utterances are labeled as ironic by their authors (using hashtags in INLINEFORM0 and the /s marker in INLINEFORM1 ). In the INLINEFORM2 example, the author uses several irony markers such as Rhetorical question (e.g., “are you telling” ...) and metaphor (e.g., “golden age”). In the INLINEFORM3 example, we notice the use of capitalization (“AWESOME”) and emoticons (“:P” (tongue out)) that the author uses to alert the readers that it is an ironic tweet. We present three contributions in this paper. First, we provide a detailed investigation of a set of theoretically-grounded irony markers (e.g., tropes, morpho-syntactic, and typographic markers) in social media. We conduct the classification and frequency analysis based on their occurrence. Second, we analyze and compare the use of irony markers on two social media platforms ( INLINEFORM0 and INLINEFORM1 ). Third, we provide an analysis of markers on topically different social media content (e.g., technology vs. political subreddits).

Question: What type of frequency analysis was used?
Answer: Mean of occurrence per utterance and the standard deviation is calculated for every marker type; the means between each pair of types is compared via independent t-tests