Algorithm to determine how positive or negative a statement/text is

Question

I need to implement sentiment analysis. Can anyone point me to examples/reference implementations?

Answer 1

http://www.uclassify.com/ http://www.uclassify.com/browse/prfekt/Mood

Answer 2

One approach is:

1. assemble a corpus of statements and text
2. manually classify each statement as positive or negative
3. ensure your corpus is "large enough" in size, e.g. ~1,000 classifications
4. run the corpus through pattern recognition software such as CRM114: http://en.wikipedia.org/wiki/CRM114%5F%28program)
5. use the resulting "brain file" to classify future statements