Winking face emoticon most effective to convey sarcasm

The simple winking face emoticon may be the most effective device to convey sarcasm in an ambiguous message, according to new study.
Researchers at the University of Nottingham in the UK conducted two experiments involving nearly 200 undergraduate students.
In the first experiment the context of each message was made clear, making any sarcasm pretty unambiguous. In the second, no explicit context was described, so a message from one person to another could be taken literally or sarcastically.
Across the two experiments, the researchers tested the effect of various emoticons and punctuation on the students' perceptions of each message's sarcasm, and their perceptions of its likely emotional impact on the recipient.

The emoticons tested were the winking face ;-) and the tongue face :-P.
The researchers used the simple text-based versions of these emoticons, not the cartoon-style emoji equivalents. The punctuation marks tested were an exclamation mark, an ellipsis, or a simple full-stop.

The findings published by the British Psychological Society's Research Digest showed that when the context for a sarcastic message was explicit and unambiguous, neither emoticons nor punctuation devices did anything to increase the likelihood that it would be perceived as sarcastic.
However, the two emoticons and ellipsis did make literal messages seem more sarcastic. Also, in these unambiguous contexts, an exclamation mark or emoticon tended to make the messages seem more positive.

When the context for a message was ambiguous, the winking face emoticon was the most effective device for provoking in students the perception that the message was sarcastic, whether it was superficially positive or negative.
According to researchers, if you want your message to be interpreted sarcastically in an ambiguous context, the best way to ensure this is to add a winking emoticon.
In an ambiguous context, sarcastic criticism was perceived as more negative when it was accompanied by a wink (or an ellipsis).
Conversely, a sarcastic comment intended as praise was perceived as more positive when combined with a wink.

If you want to praise or criticise someone by text, and you want to blunt the emotional impact, using sarcasm is one way to achieve this effect, researchers said.